This. Earth Centre. Malmo. Lillie Road. Fulham. Sweden Towards the less unsustainable city 192 192 193 195 195 196 196 197 197 197 198 198 198 199 199 200 200 202 202 203 205 205 206 207 207 208 209 211 212 212 214 217 217 218 225 235 236 238 viii . Doncaster Recycling strategy checklist 18 State of the art case studies The National Assembly for Wales Zuckermann Institute for Connective Environmental Research (ZICER) Social housing Beaufort Court. 2003 Beddington Zero Energy Development (BedZED) Beaufort court renewable energy centre zero emissions building 19 Integrated district environmental design Ecological City of Tomorrow. .CONTENTS 20 An American perspective Glenwood Park. Atlanta.
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at the same time. As populations increase and. Students and practitioners alike within the construction industry need to be aware of the importance of their role in creating architecture which not only raises the quality of life but also ensures that such quality is sustainable.Foreword This updated book is essential reading especially as it considers the ‘why’ as well as the ‘what’ of sustainable architecture. gravitate to cities. There is now wide agreement that halting global warming and its climatic consequences is likely to be the greatest challenge that we shall face in this century. Lord Rogers of Riverside xi . buildings old and new should be a prime target in the battle to reverse the demand for fossil-based energy.
David Hammond Architects. Nick White of the Hockerton Housing Project. Dr Adrian Pitts of Sheffield University. Bill Dunster Architects. Dr William Bordass for providing information from his ‘Probe’ studies. xii . Grimshaw Architects Ove Arup and Partners. Richard Rogers Partnership.Acknowledgements I should like to express my thanks to the following practices for their help in providing illustrations and commenting on the text: Bennetts Associates. Michael Hopkins and Partners. Ray Morgan of Woking Borough Council and finally Rick Wilberforce of Pilkington plc for keeping me up to date with developments in glazing. RMJM. Foster and Partners. Fielden Clegg Bradley. Studio E Architects. Jestico Whiles. I am also indebted to Dr Randall Thomas for his valuable advice on the text. Alan Short Architects.
Introduction This book calls for changes in the way we build.6 billion. This is followed by an outline of the international efforts to curb the rise in greenhouse gases.. A difficulty encountered by many architects is that of persuading clients of the importance of buildings in the overall strategy to reduce carbon dioxide emissions. at this rate by 2030 it will reach 1. The first part of the book seeks to set out those reasons by arguing that there is convincing evidence that climate changes now under way are primarily due to human activity in releasing carbon dioxide (CO2) into the atmosphere. The first chapters of the book explain the mechanism of the greenhouse effect and then summarise the present situation vis-à-vis global warming and climate change. a problem that will gather momentum as developing countries like China and India maintain their dramatic rates of economic growth. At the same time it is important to appreciate that there are absolute limits to the availability of fossil fuels. For change to be widely accepted there have to be convincing reasons why long-established practices should be replaced. The book is designed to promote a creative partnership between the professions to produce buildings which achieve optimum conditions for their inhabitants whilst making minimum demands on fossil-based energy. meaning that there is a constructive dialogue between architects and services engineers at the inception of a project. The crucial factor is that the great bulk of this population is concentrated in the great valleys of the Yangtze and Yellow Rivers and xiii .3 billion population. One of the guiding principles in the production of buildings is that of integrated design. Buildings are particularly implicated in this process. By 2005 it had reached 1. This being the case it is appropriate that the design and construction of buildings should be a prime factor in the drive to mitigate the effects of climate change. China may well serve to give a foretaste of the future.
A supply of energy sufficient to match the rate of economic growth is China’s prime concern. 50 per cent is absorbed and re-radiated.INTRODUCTION their tributaries. According to a spokesman for the Academy of Engineering of China. like the range of pollutants released by the burning of fossil fuels. The Earth receives annually energy from the sun equivalent to 178 000 terawatt years which is around 15 000 times the present worldwide energy consumption. The pre-industrial atmospheric concentration of CO2 was around 270 parts per million by volume (ppmv). China is on the verge of consuming more than it can produce. By 2025 it will be importing 175 million tonnes of grain per year and by 2030 200 million tonnes. 30 per cent is reflected back into space. the 800 plus figure looks ever more likely unless there are widespread and radical strategies that bypass political agreements. Carbon has been slowly locked in the earth over millions of years creating massive fossil reserves. an area about the size of the USA. which equals present total world exports (US National Intelligence Council). Between January and April 2004 demand for energy rose 16 per cent. The greatest potential for realising this change lies in the sphere of buildings. The problem is that these reserves of carbon are being released as carbon dioxide into the atmosphere at a rate unprecedented in the paleoclimatic record. Its appetite for steel and building materials is voracious and already pushing up world prices. In 2003 it spent £13 billion on hydroelectric. eight gas pipelines. Given the absence of a political consensus following the refusal of the US to ratify the Kyoto Protocol. The security of the planet rests on our ability and willingness to use this free energy without creating unsavoury side effects. The aim of the scientific community is that we should stabilise atmospheric CO2 at under 500 ppmv by 2050 acknowledging that this total will nevertheless cause severe climate damage. if the present trend is maintained we could expect concentrations exceeding 800 ppmv by the second half of the century. account for almost 50 per cent of all CO2 emissions. Today it is approximately 380 ppmv and is rising by about 20 ppmv per decade. The opportunity rests with architects and services engineers to bring about this step-change in the way buildings are designed. and this is where architects and engineers have a crucial part to play. in the UK. However. and 20 per cent powers the hydrological cycle. 20 nuclear power stations and 400 thermal power generators. Only 0.6 per cent powers photosynthesis from which all life derives and which created our reserves of fossil fuel. In the 1960s–1970s buildings were symbols xiv . coal fired and nuclear power plants – a rate of expansion that equals Britain’s entire electrical output every two years. which. six new oil fields. 26 Yanzhou coal mines. the country will need an additional supply equivalent to four more Three Gorges hydroelectric dams. Of that. Already demonstration projects have proved that reductions can reach 80–90 per cent against the current norm. The technology exists to cut this by half in both new and existing buildings.
large reductions of global emissions will be necessary during this century and the next. It concludes: ‘To limit the damage beyond that which is already in train. Smith January 2005 xv . In 2000 the Royal Commission on Environmental Pollution produced a report on Energy – The Changing Climate. Strong and effective action has to start immediately. Nowhere can this be better demonstrated than in the design of buildings. challenging nature at every step.’ Peter F. The turn of the millennium saw a new attitude gathering momentum in a synergy between human activity and the forces of nature.INTRODUCTION of human hubris.
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leaves. through photosynthesis. This should be good enough to persuade us that human action can ultimately put a brake on the progress of global warming and its climate consequences. etc. The mechanism of the carbon cycle operates on the basis that the carbon locked in plants and animals is gradually released into the atmosphere after they die and decompose. a commitment to renewable energy sources and bioclimatic architectural design should become unavoidable. The carbon then enters the food chain as the plants are eaten by animals. so. The former is estimated to 1 . There is widespread agreement among climate scientists worldwide that the present clear evidence of climate change is 90 per cent certain to be due to human activity mainly though the burning of fossil-based energy.Climate change – nature or human nature? Chapter One The key question is this: climate change is now widely accepted as being a reality. Carbon compounds in the atmosphere play a major part in ensuring that the planet is warm enough to support its rich diversity of life. There is also a geochemical component to the cycle mainly consisting of deep ocean water and rocks. Inspiring that commitment is the purpose of the first part of the book which then goes on to illustrate the kind of architecture that will have to happen as part of a broader campaign to avert the apocalyptic prospect of catastrophic climate change. Once the issues are understood.. Compounds of the element form the basis of plants. then it follows that we ought to be able to do something about it. The carbon cycle Carbon is the key element for life on Earth. On the other hand. if we accept that it is largely human induced. This atmospheric carbon is then taken up by plants which convert carbon dioxide (CO2) into stems. animals and micro-organisms. trunks.
when forests are converted to cropland the carbon in the vegetation is oxidised through burning and decomposition. The main greenhouse gases are water vapour. 2 . nitrous oxide and tropospheric ozone (the troposphere is the lowest 10–15 kilometres of the atmosphere). The greenhouse effect is caused by long-wave radiation being reflected by the Earth back into the atmosphere and then reflected back by trace gases in the cooler upper atmosphere. infra-red energy is determined by the temperature of the Earthatmosphere system. in turn. The main human activity responsible for overturning the balance of the carbon cycle is the burning of fossil fuels which adds a further 6 billion tonnes of carbon to the atmosphere over and above the natural flux each year. thus warming the Earth’s surface. The system is in equilibrium.ARCHITECTURE IN A CLIMATE OF CHANGE contain 36 billion tonnes and the latter 75 million billion tonnes of carbon. the CO2 in the atmosphere will treble by 2100. is pushing up global temperatures. biota. The burning of one hectare of forest gives off between 300 and 700 tonnes of CO2. every kilowatt hour of electricity used in the UK releases one kilogram of CO2. If fossil fuels are burnt and vegetation continues to be destroyed at the present rate. Without the greenhouse shield the Earth would be 33 C cooler. In addition. ice caps and the atmosphere. These are some of the factors which account for the serious imbalance within the carbon cycle which is forcing the pace of the greenhouse effect which. This terrestrial radiation in the form of longwave. The balance between radiation and absorption can change due to natural causes such as the 11-year solar cycle. The greenhouse effect A variety of gases collaborate to form a canopy over the Earth which causes some solar radiation to be reflected back from the atmosphere. Soil cultivation and erosion add further carbon dioxide to the atmosphere. Volcanic eruptions and the weathering of rocks release this carbon at a relatively slow rate. Under natural conditions the release of carbon into the atmosphere is balanced by the absorption of CO2 by plants. thus causing additional warming of the Earth’s surface (Figure 1. carbon dioxide. hence the greenhouse analogy. or would be if it were not for human interference. one third is reflected back into space and the remainder is absorbed by the land. Under natural conditions the solar energy absorbed by these features is balanced by outgoing radiation from the Earth and atmosphere. Even if there is decisive action on a global scale to reduce carbon emissions. atmospheric concentrations will still double by this date. Of the solar radiation which reaches the Earth. With the present fuel mix. The sun provides the energy which drives weather and climate. with obvious consequences for life on the planet. methane.1). oceans.
Finally. Ice core samples give information in four ways. the air trapped in the snow layers gives a measurement of the CO2 in the atmosphere in a 3 . rising population in the less developed countries has led to a doubling of methane emissions from rice fields. Climate change – the paleoclimate record In June 1990 scientists were brought up sharp by a graph which appeared in the journal Nature (Figure 1.CLIMATE CHANGE – NATURE OR HUMAN NATURE? a year Earth’s surface Figure 1. their melt layers provide an indication of the time span covered by the core. Second. It also revealed that present concentrations of CO2 are higher than at any time over that period. A third indicator is the heavy oxygen isotope 18O in air trapped in the ice. Nitrous oxide emissions have increased by 8 per cent since pre-industrial times (IPCC 1992). at the very least.2). It is more abundant in warm years. been maintained. In addition. a measurement of the extent to which ice melted and refroze after a given summer gives a picture of the relative warmth of that summer. cattle and the burning of biomass. Since then the rate of increase has. Methane is a much more powerful greenhouse gas than carbon dioxide. the combustion of fossil fuels and deforestation has resulted in an increase of 26 per cent in carbon dioxide concentrations in the atmosphere. It was evidence from ice core samples which showed a remarkably close correlation between temperature and concentrations of CO2 in the atmosphere from 160 000 years ago until 1989.1 The greenhouse ‘blanket’ Since the industrial revolution. First.
A major cause of climate fluctuation has been the variation in the Earth’s axial tilt and the path of its orbit round the sun. it will be necessary to consider the causes of dramatic changes in the past. In northern latitudes warmth is the decisive factor. Some of the best data come from within the Arctic Circle where pine logs provide a 6000-year record.ARCHITECTURE IN A CLIMATE OF CHANGE Figure 1. at the peak of the last ice age 20 000 years ago.2 Correspondence between historic temperature and carbon dioxide given year. Their orbits produce a fluctuating gravitational pull on the Earth. Another source of what is called ‘proxy’ evidence comes from analysing tree rings. the more favourable the climate to growth. Causes of climate fluctuation To be able to see the current changes in climate in context. This can give a snapshot of climate going back 6000 years. Other data from ice cores show that. The thicker the ring. sea level was about 150 m lower than today. affecting the angle of its 4 . The Climate Research Unit of the University of East Anglia has made a special study of the evidence for climate changes from different sources and has concluded that there is a close affinity between ice core evidence and that obtained from tree rings. Also instrumental records going back to the sixteenth century are consistent with the proxy evidence. Each tree ring records one year of growth and the size of each ring offers a reliable indication of that year’s climate. The Earth is subject to the influence of neighbouring planets.
In the short term this can lead to a cooling as the dust cuts out solar radiation. So. The effect was to shut down the conveyor belt. what is the relevance of the icebergs? As these armadas of icebergs melted as they came south they produced huge amounts of fresh water which lowered the density of surface water undermining its ability to descend to the ocean floor. Particularly salty and warm surface water migrates from the tropics towards the north Atlantic. Cambridge University Press. (2004) Global Warming. As a result northern Europe was periodically plunged into arctic conditions and scientists are concerned that there is now evidence that this process is beginning to happen due to melting ice in the southern tip of Greenland. when plates collide. It accounts for 25 per cent of the heat budget of northwest Europe. In themselves mountains add to the stirring effect on the atmosphere in concert with the rotation of the Earth. This. draws warmer water from the tropics which is why it is also called the conveyor belt or deep ocean pump. as a consequence. They also generate fluctuations in atmospheric pressure. After the melted iceberg water had dispersed. It has been calculated that the current orbital configuration is similar to that of the warm interglacial period 400 000 years ago. The surface of the Earth is constantly shifting. the conveyor started up again 5 . A third factor may be a consequence of the second. A feature of plate tectonics is that. the axis could move to 90 degrees from the vertical meaning that half the planet would have permanent summer and the other endless winter. As it moves north it gradually becomes cold and dense. In the longer term. one plate slides under the other. (For more information on climate fluctuations over the past million years see Houghton J. thanks to the stabilising pull of the moon. in turn. and. in turn.) A second factor forcing climate change is the movement of tectonic plates and the resultant formation of volcanic mountains. all of which affect climate. Without the moon. We may indeed be in the early stages of an interglacial episode and the accompanying natural warming which is being augmented by human induced warming. large injections of CO2 lead to warming. Paleoclimate data show that there have been periodic surges of ice flows into the north Atlantic which. As the Earth wobbles. vast ice sheets wax and wane over a cycle called a Milankovitch cycle. To understand why the ice flows affect the Gulf Stream we need to look at what drives this rather special current. notably the Gulf Stream. the variation in tilt is contained within limits which preserves the integrity of the seasons. However.CLIMATE CHANGE – NATURE OR HUMAN NATURE? axis. The collision of plates accounts for the formation of mountains. this is called subduction. 3rd edn. releasing vast quantities of debris and CO2 in the process. affect the deep ocean currents. near Greenland it plunges to the ocean floor. In the process rocks are heated and forced through the surface as volcanoes. since CO2 has a relatively long life in the atmosphere. But it is volcanic activity which can cause dramatic changes.
the worst being from 1000 to 1270 (Nature. The stability of that planet – no plate movement or vegetation to hide the evidence – ensures that we have a picture of meteor bombardment over hundreds of millennia. Changes in energy levels emitted by the sun are also implicated in global fluctuations. it is the third in the sequence that warrants most attention because it has contemporary 6 . This. Photosynthesising plants were deprived of their energy source and food chains collapsed resulting in the extinction of 75–80 per cent of species. notably the dinosaurs. However. and the evidence indicates that cooling was relatively slow whilst warming was rapid – 10–12 C in a lifetime. 403. For some reason these forays of icebergs stopped about 8000 years ago. Periods of high water have higher concentrations of algae on the lake floor which translates to a higher carbon content in the annual layers of sediment. Sediment in Lake Naivasha in the Kenya Rift Valley reveals the levels of lake water over the past 1000 years. In June 1999 the journal Nature (vol. leads to huge demands for CO2 which is drawn from the atmosphere. There were long periods of intense drought leading to famine and mass migrations. of all the other mass extinctions. The Earth will have been no different. Some of the best evidence for the climatic effects of varying levels of radiative output from the sun comes from Africa. 437) published research evidence from the Rutherford Appleton Laboratory in Didcot. in turn. creating relatively stable conditions which facilitated the development of agriculture and ultimately the emergence of urban civilisations. The dinosaurs will testify to the effect on climate of meteor strikes creating perpetual night. vol. 399. There is strong historic evidence that life on Earth has a precarious foothold. The most widely known on the popular level is the final one which occurred at the end of the Cretacious period 65 million years ago. p. A fourth factor may seem ironic. New sites of catastrophic impacts are still being discovered on the Earth. but if we want a true picture of the historic record of meteor impact we can see it on Venus.ARCHITECTURE IN A CLIMATE OF CHANGE leading to rapid warming. we cannot ignore wider cosmic effects. The result of this stripping of atmospheric CO2 is a weakening of the greenhouse shield. yet the rate of warming has been increasing. because ice ages can be triggered by warm spells leading to the rapid expansion of forests. It is widely attributed to one or more massive meteorites that struck the Earth propelling huge quantities of debris into the atmosphere masking the sun probably for years. This cycle occurred 20 times in 60 000 years. 410). resulting in sharply dropping temperatures. The palaeontological record shows that there have been five mass extinctions in the recorded history of the planet. However. Finally. indicating that increased greenhouse gases are the culprit. Oxfordshire which suggests that half the global warming over the last 160 years has been due to the increasing brightness of the sun. p. since 1970 the sun has become less responsible for the warming.
It took 50 million years for the planet to return to anything like the previous rate of biodiversity (New Scientist. European Union Research Commissioner). At the end of the Permian period. For the next 5 million years the remaining 5 per cent of species clung to a precarious existence. ‘Wipeout’). Greater extremes of the hydrological cycle are leading. 251 million years ago. A chain of events caused massive expulsions of CO2 into the atmosphere which led to rapid warming and plant growth. on the one hand. In July 2004 Southeast Asia experienced catastrophic floods due to exceptional rainfall. It is the widescale evidence of anomalous climatic events coupled with the rate at which they are occurring that has persuaded the IPCC scientists that much of the blame lies with human activity. In both cases there is a loss of carbon fixing greenery and food producing land. 26 April 2003. and. This had the effect of stripping much of the oxygen from the atmosphere leading to a collapse of much of the biosphere. The following year saw a similar occurrence with the rivers Elbe and Rhone bursting their banks. to increased area of desert. a catastrophic chain of events caused the extinction of 95 per cent of all species on Earth. thereby intensifying the dynamics of weather systems. At the same time central China also 7 . Plants and animals literally suffocated. In the first months of 2000 Mozambique experienced catastrophic floods which were repeated in 2001. The prime cause was a massive and prolonged period of volcanic eruptions. on the other. not from mountains but from extensive fissures in the ground in the region which ultimately became Siberia. The importance of this evidence lies in the fact that this mass extinction occurred because the planet warmed by a mere 6 C over a relatively short period in the paleoclimate timescale. In 2002 devastating floods occurred across Europe inundating historic cities like Prague and Dresden creating ‘one of the worst flood catastrophes since the Middle Ages’ (Philippe Busquin. rendering 30 million homeless in Bangladesh and the Indian state of Bihar. greater intensity of rain storms which increase run-off and erosion of fertile land.CLIMATE CHANGE – NATURE OR HUMAN NATURE? relevance.. The evidence ● ● ● There has been a marked increase in the incidence and severity of storms over recent decades. Over the past 50 years high pressure systems have increased by an average of three millibars whilst low pressure troughs have deepened by the same amount.
There is even talk that the El Niño reversal may become a fixture which would have dire consequences for Australia and Southeast Asia. Insurance companies are good barometers of change. The people of Ethiopia are facing starvation in their millions because of the year-by-year failure of the rains. Sea temperatures in Antarctica are rising at five times the global average. states that claims due to storms have doubled in every decade since 1960. 22 October 2000). In that decade there were 16 disasters costing £30 billion. km of the Larson B ice shelf has serious implications. following the collapse of the Larson ice shelf ‘inland [land based] glaciers have surged dramatically towards the coast in recent years’. Besides the effect of increasingly steep pressure gradients another factor contributing to the intensification of storms is the contraction of snow fields. Munich Re. Yet. losses will be ‘unimaginable’. The increased frequency of storms and floods in this area during the last decade of the twentieth century adds weight to this conclusion. January 2001). by the middle of this century. at present a 2. these extreme climatic events are only part of the scenario of global warming. In the May 2003 edition of Scientific American it was reported that. The recent breakaway of the 12 000 sq.65 km ● ● ● ● ● ● 8 . One of the largest. Up to now much of the sea level rise has been due to thermal expansion. These have in the past created high pressure zones of cold stable air which have kept at bay the Atlantic lows with their attendant storms. In itself it will not contribute to rising sea levels. In Iceland Europe’s largest glacier is breaking up and is likely to slide into the north Atlantic within the next few years. This barrier has weakened and shifted further east allowing the storms to reach western Europe.5 C increase since the 1940s. The Loss Prevention Council has stated that.ARCHITECTURE IN A CLIMATE OF CHANGE suffered devastating floods whilst Delhi experienced a major draught. The Arctic ice sheet has thinned by 40 per cent due to global warming (report by an international panel of climate scientists. The major threat lies with the potential break-up of land-based ice. El Niño has produced unprecedentedly severe effects due to the warming of the Pacific. Receding polar ice is resulting in the rapid expansion of flora. In the last decade of the century there were 70 disasters costing £250 billion. In the first years of this century the pace has quickened.25 and 1. highlighting the threat to sea levels from land-based ice (The Observer. Munich Re has reported that the 700 natural disasters in 2003 claimed 50 000 lives and cost the insurers £33 billion. Sea level has risen 250 mm (10 inches) since 1860. Antarctic summers have lengthened by up to 50 per cent since the 1970s and new species of plants have appeared as glaciers have retreated. Satellite measurements have shown that the two main glaciers have advanced 1. The danger lies in the fact that the ice shelves act as a bulwark supporting the land-based ice.
Whilst snow reflects much of the solar radiation back into space. houses subsiding and world famous ski resorts becoming non-viable. at the same time releasing huge amounts of carbon dioxide into the atmosphere – a classic positive feedback situation. in part. cit. 22). op. Together these pose serious threats to the survival of the subsistence-indigenous Eskimos (New Scientist. reducing summer rainfall. trees keeling over. as it will.5 C in the twenty-first century. 14 November 1998).3 and 0. p.CLIMATE CHANGE – NATURE OR HUMAN NATURE? respectively. This is another indication of the instability of the West Antarctic ice sheet. 23 July 2004). The average global surface temperature in 1998 set a new record surpassing the previous record in 1995 by 0. the bare tundra absorbs heat. increasing storm intensity. This may. At the same time there has been massive melting of glacier ice on mountains. They anticipated that temperatures would rise between 1 and 3. migration patterns and numbers of some wildlife species. serious infrastructure problems are occurring due to the melting of the permafrost.. March 1999). this will raise sea level by 5 m (Scientific American. the Pine Island glacier.4 metres per day.2 C – the largest jump ever recorded (Worldwatch Institute in Scientific American. The sea is moving inland at the rate of 3 m a year (BBC News. This makes it probable ● ● ● ● 9 . Roads are splitting apart. Some houses have already fallen into the sea. in only a short time the rate of warming is already equivalent to a 3 C rise per century. The warmest year on record was 1999. Global mean surface air temperature has increased between 0. Global warming is increasing at a faster rate than predicted by the UN IPCC scientists in 1995. drying tundra. According to the Director of the US National Climate Data Center. is rapidly thinning – 10 metres in eight years – and accelerating towards the sea at a rate of 8 metres a day. be due to the melting of the snow fields exposing tundra. That represents a rate of 1. In Alaska there is general thinning and retreating of sea ice. others are crumbling due to the melting of the permafrost supporting their foundations. In Alaska and much of the Arctic temperatures are rising ten times faster than the global average – 4. The International Commission on Snow and Ice has reported that glaciers in the Himalayas are receding faster than anywhere else on Earth. Even more disconcerting is the fact that the largest glacier in Antarctica. In April 1999 The Guardian reported that this ice shelf was breaking up 15 times faster than predicted. When the West Antarctic ice sheet totally collapses. From Alaska to Siberia. The Alps have lost 50 per cent of their ice in the past century..6 C since the later nineteenth century.4 C in 30 years.8 and 2.
this is the highest concentration in 55 million years. According to Sir David King. concentrations could reach 800–1000 ppmv by 2100. A study of European gardens found that the growing season has expanded by at least ten days since 1960. Most of the increase has occurred over the last 50 years. this threatens the Gulf Stream or deep ocean pump and on the other. not only in terms of peak temperatures but also their ● ● ● ● ● 10 .5 C. The pre-industrial level was 590 billion tonnes or 270 parts per million by volume (ppmv). February 1999). Spring in the northern hemisphere is arriving at least one week earlier than 20 years ago. 29 January 2000. it leads directly to a rise in sea level. 42–43). Bearing in mind the observed rate of temperature increase as mentioned above. The summer of 2003 saw heatwaves across Europe that were exceptional. The previous highest concentration was 300 ppmv 300 000 years ago (New Scientist. UK Chief Government Scientist. vol. some estimates put it at 11 days. the aim now should be to prevent the planet crossing the threshold into runaway global warming whereby mutually reinforcing feedback loops become unstoppable. The conclusion was that spring arrived on average six days earlier and autumn five days later over a 30-year period (Nature. Altogether it would seem that a temperature rise of at least 6 C is very possible with the worst case scenario now rising to 11. A 40-year survey by Nigel Hepper at the Royal Botanical Gardens at Kew involving 5000 species indicates that spring is arriving ‘several weeks earlier’. Over the past 20 years the polar ice cap has thinned by 40 per cent. Water is lost through sweating and this leads to higher levels of red blood cells. Munich scientists studied 70 botanical gardens from Finland to the Balkans (616 spring records and 178 autumn). pp. The process starts within 30 minutes of exposure to sun. NASA scientists report satellite evidence of the Greenland landbased ice sheet thinning by 1 m per year. On the one hand. 719). The majority of heat-related deaths are due to a lethal assault on the blood’s chemistry. 5 March 1999). Extreme heat episodes are becoming a feature of hitherto temperate climate zones. At the present rate of emission. Altogether it has lost 5 m in southwest and east coasts. Then there was no ice on the planet. Concentrations of CO2 in the atmosphere are increasing at a steep rate. now it is 760 billion tonnes or around 380 ppmv and rising 1.ARCHITECTURE IN A CLIMATE OF CHANGE that the end of century temperature level will be significantly higher than the IPCC top estimate (Geophysical Research Letters. 27. Even if emissions were to be reduced by 60 per cent against 1990 levels by 2050 this will still raise levels to over 500 ppmv with unpredictable consequences due to the fact that CO2 concentrations survive in the atmosphere for at least 100 years. clotting factors and cholesterol. p.5–2 ppmv per year. threatening coastal regions (Nature.
Worldwide the assessment is £50 billion. Harvard University. which not only means higher temperatures but also more extensive swings of atmospheric pressure.CLIMATE CHANGE – NATURE OR HUMAN NATURE? duration. nasty and irreversible’ change (Bill Clark. the cost of premature death due to rising numbers of heatwaves is reckoned to be £14 billion a year in the EU and £11 billion in the US. Towards the latter part of the century they predict such an event every second year. quoted in New Scientist. As they warm they are becoming less efficient at absorbing CO2. 11 . According to the UN Environment Protection Agency director. This has not happened since prehistoric interglacial warming. on the evidence of climate changes to date. To repeat. this kind of sustained summer temperature could normally be expected every 450 years. 22 November 2003). where there were 29 sudden deaths in one night. The study also showed that a drop in temperature of 10 C increases the risk of a heart attack by the same percentage (reported at a meeting of the American Heart Association. North Australia. Research at the University of Lille has indicated that when the pressure falls below 1006 millibars or rises above 1026 millibars the risk of heart attacks increases by 13 per cent. The evidence from ice cores reveals that the planet has sometimes swung dramatically between extremes of climate in a relatively short time due to powerful feedback that tips the system into a dramatically different steady state. Scientists meeting for a workshop in Berlin in 2003 concluded. The year 2000 saw an unprecedented catalogue of warnings. According to scientists in Zurich reporting in ‘Nature on-line’. Oceans are the largest carbon sink. The latest prediction is that the carbon absorption capacity of oceans will decline by 50 per cent as sea temperatures rise. Methane emissions from natural wetlands and rice paddy fields are increasing as temperatures rise. the assumption generally held by policy makers is that a steady rise in CO2 concentrations will produce an equally steady rise in temperature. 35 000 died in August across Europe and 14 800 in France alone from heat-related causes. According to the Earth Policy Institute in Washington DC. methane is a much more potent greenhouse gas than CO2 and levels are rising rapidly.5 C which was the highest early February temperature since records began in 1772 according to the UK Meteorological Office. November 1998). The warming that is eroding Europe’s largest glacier in Iceland also created clear water across the North West Passage at the top of Canada making navigation possible. Dallas. Other estimates put the figures at 20 000 and 11 000 respectively. That month was also the occasion of a severe heatwave in Brisbane. that the planet could be on the verge of ‘abrupt. On 4 February 2004 the temperature in central England reached 12. One of the predicted results of global warming is that there will be greater extremes of weather. ● ● ● ● Finally.
There is a serious risk of this happening to the West Antarctic and Greenland ice sheets and their loss would mean a 12 m rise in sea level (Geology. Singapore and its reclaimed territories will be at risk if the sea level rises above 20 cm. Ultimately. 14 July 2004). Many millions of people live below one metre above sea level. vol. 27. This would occur if all the world’s vast ice sheets disintegrated. For example. at its extreme. words attributed to Jonathan Gregory of the Hadley Centre. The same report stated that Alaska is 8 C warmer than 30 years ago. According to a BBC report (28 July 2004) the Greenland ice sheet is melting ten times faster than previously thought. Here are some of the predictions. p. 375). Ancient shorelines show that. The condition of the Greenland ice cap is another cause for concern. Since May 2004 the ice thickness has reduced by 2–3 m. sea level was 20 m (70 ft) above the present level during an interglacial period 400 000 years ago. The mean high tidal water level has increased between 40 and 50 cm since the 1970s. ● ● ● ● Historic sea levels are well recorded in the Bahamas and Bermuda because these islands have not been subject to tectonic rise and fall. This BaU scenario assumes some changes and improvements in efficiency in technology. The Guardian. Hamburg is 120 kilometres from the sea but could be inundated. The Thames barrage is already deemed to be inadequate. 12 . 22 November 2003). In 2001 Antarctic scientists indicated that sea levels could rise by 6 m (20 ft) within 25 years (Reuters). ‘Doomsday Scenario’. According to one scenario ‘warming of less than 3 C – likely in that part of the Arctic within a couple of decades – could start a runaway melting that will eventually raise sea levels worldwide by seven metres’ (New Scientist.
Salination following storm surges will render this land sterile.PREDICTIONS ● In the UK rising sea levels threaten 10 000 hectares of mudflats and salt marshes. The University of East Anglia Environmental Risk Unit predicts that the 1 in 100 year storm and related floods will show a return rate by 2030 for: Milford Haven Cardiff Portland Newhaven Colchester 3. Sir David King. predicts that global warming. coastal erosion and the practice of building on flood plains will increasingly raise the level of risk of loss of life and extensive property damage. The panel of scientists behind the report considered four scenarios. But the most serious threat is to 50 per cent of England’s grade 1 agricultural land which lies below the 5 m contour (Figure 2.1 Land below 5 metre and 10 metre contours 13 .5 yrs 5 yrs 5 yrs 3 yrs 4 yrs ● A report from a committee chaired by the UK’s Chief Government Scientist.1). The two worst case scenarios more or less correspond to the IPCC Land below 5 m AOD Land between 5 and 10 m AOD Lowestoft Colchester Sheerness Newhaven Figure 2.
6 million today to 3. The cost to the economy could be £27 billion per year (Future Flooding.ARCHITECTURE IN A CLIMATE OF CHANGE Business as Usual scenario in which there is unrestricted economic development and hardly any constraints on pollution.6 million by the 2080s. He went on: ‘I am sure that climate change is the biggest problem that civilisation has had to face in 5000 years’ which gives added weight to his pronouncement in January 2004 that climate change poses a greater threat than international terrorism. cities like London. On current trends. since which time the swings have been much more moderate. April 2004) (Figure 2. ● It was stated earlier that the geological record over 300 million years shows considerable climate swings every 1–2000 years until 8000 years ago. The danger is that increasing atmospheric carbon up to treble the pre-industrial level will trigger a return to this pattern.2). The report concludes that the population at risk from coastal erosion and flooding could increase from 1. since we are melting ice so fast.2 Areas in England and Wales at risk of flooding by 2080 under worst case scenario (from the Office of Science and Technology Foresight Report. The IPCC Scientific Committee believes that the absolute limit of Figure 2. In an interview with The Guardian (14 July 2004) Sir David King stated: You might think it is not wise. New York and New Orleans will be among the first to go. a report from the Flood and Coastal Defence Project of the Foresight Programme. April 2004) 14 . Future Flooding. to have built our big cities on the edge of the sea where it is now obvious they cannot remain.
3). but that warming was rapid as stated earlier. seasonal malaria will have a firm foothold in southern Britain.PREDICTIONS accumulation of atmospheric carbon should be fixed at double the pre-industrial level at around 500 parts per million by volume (ppmv). The Department also estimated that there will be around 3000 deaths a year from heatstroke – a prediction seriously understated if the summer of 2003 sets the pace of change. including the deadly plasmodium falciparum strain which kills around one million children a year in Africa (Figure 2. It is already widely understood that illnesses like vector borne malaria and Leishmaniasis (affecting the liver and spleen) are predicted to spread to northern Europe. Pests and pathogens are migrating to temperate latitudes. The incidence of the fatal disease West Nile fever has increased in warm temperate zones. New York had an outbreak in 1999. IPCC scientists consider that the net ● ● ● Figure 2. A warmer atmosphere means greater evaporation with a consequent increase in cloud cover. by 2020. The UK Department of Health predicts that. Global warming poses a serious threat to health. 9 February 2001). Higher temperatures would also increase the incidence of food poisoning by 10 000 (Department of Health review of the effects of climate change on the nation’s health. Even this will have dramatic climate consequences.3 Predicted spread of seasonal malaria in Britain by 2020 15 . The paleoclimate record shows that generally cooling occurred at a slow rate. for example 12 C in a lifetime.
A report from the Calicut University. thus returning 77 gigatonnes (billion) of carbon to the atmosphere. p. Melting glaciers in the Andes and Rocky Mountains will cause similar problems in the Americas (New Scientist. However. For example. Some regions ● ● ● ● 16 . It is predicted that the largest of these lakes in the Sagarmatha National Park in Nepal currently holding 30 million cubic metres of water will break out within five years (New Scientist. The worldwide melting of glaciers and ice caps will contribute 33 per cent of the predicted sea level rise (IPCC). 8 May 2004). In the short term this could mean a net loss in the carbon fixing capacity of the forest since the understorey trees are slower growing and denser in carbon content. The Hadley Centre forecasts that global warming will cause forests to grow faster over the next 50 years. p. Taller. Indian and Nepalese researchers predicts that the great rivers of northern India and Pakistan will flow strongly for about 40 years causing widespread flooding. 5 June 1999). by British. average temperature rose by 5 C in 10 years 14 000 years ago. Meltwater is held back by the mound of debris marking the earlier extremity of the glacier path. Historically relatively abrupt changes in climate have been triggered by vegetation. Another danger is posed by the rapid accumulation of meltwater lakes. 12. the world’s largest reinsurance group. p. It is estimated that all the glaciers in the central and eastern Himalayas will disappear by 2035. Nature could still be the deciding factor. In the longer term the latter trees are likely to be more susceptible to die-back through heat and drought (New Scientist. Canopy trees are faster growing and lower in carbon content. Earlier it was said that the paleoclimate record shows that in the past the explosive growth of vegetation absorbed massive amounts of atmospheric carbon resulting in a severe weakening of the greenhouse effect and a consequent ice age. 13 March 2004). These mounds are unstable and periodically collapse with devastating results. He states: ‘There is reason to fear that climatic changes in nearly all regions of the Earth will lead to natural catastrophes of hitherto unknown force and frequency. faster growing trees are taking over from the slower growing trees of the understorey of the forest. Already there is evidence of changes in growth patterns in the Amazon rainforest. This will bring a high risk of runaway global warming. This is attributed to the higher levels of CO2 in the atmosphere. 18. 7. Water vapour is a potent greenhouse gas. After this date most of the glaciers will have disappeared creating dire problems for populations reliant on rivers fed by melt ice like the Indus and Ganges. predicts that claims within the decade 2040–2050 will have totalled £2000 billion based on the IPCC estimates of the rise in atmospheric carbon. from about 2050 the increasing warming will kill many of the forests. The head of research at Munich Re. absorbing more than 100 billion tonnes of carbon.ARCHITECTURE IN A CLIMATE OF CHANGE effect will be to increase global warming. Kerala.
by the middle of the century. Global warming is causing peat bogs to dissolve.2 billion will rise to 9. The US Census Bureau predicted in March 2004 that the present population of 6. At present the greatest concentrations of population are in coastal regions which will be devastated if sea level rise predictions are fulfilled. The model suggested that warming could reach up to 10 C on the basis of a doubling of atmospheric CO2 which is widely regarded as inevitable. We have to add to these natural events the prediction that there will be a substantial increase in world population. There it feeds bacteria in the water which. DOC from peat bogs could be as great a source of atmospheric CO2 as the burning of fossil fuels. 24 July 2004).2 billion by that date. The worry is that global warming will either reduce the global level of cloud cover or change the character of the clouds and their influence on solar radiation. Even at present 1. in turn. Research in the University of Wales at Bangor indicates that ‘The world’s peatland stores of carbon are emptying at an alarming rate’ (Chris Freeman). Recent modelling conducted by James Murphy of the Met Office Hadley Centre for Climate Prediction has factored in a range of uncertainties in cloud formations such as cloud cover. The uncertainty with perhaps the greatest potential to derail current predictions about global warming is the role of the clouds. mostly in areas which can least accommodate it. 3 February 2001). Add them to climate models and some frightening possibilities fall out’ (Fred Pierce. It then believes that the rate of fertility will fall below the replacement level. Peat bogs store huge quantities of carbon and the evidence is that this is leaching into rivers in the form of dissolved organic carbon (DOC) at the rate of about 6 per cent per year. Bacteria in rivers rapidly convert DOC into CO2 that is released into the atmosphere. Freeman predicts that.3 billion. New Scientist. described by New Scientist as ‘the wild card in global warming predictions. The UN Population Division estimates that the world figure will reach 8. of the total world population live in extreme poverty on less than $1 per day. ● Recent uncertainties An article of 10 July 2004 in New Scientist was headed ‘Peat bogs harbour carbon time bomb’. It appears to be another feedback loop in that an increase in CO2 in the atmosphere is absorbed by vegetation which in turn releases it into the soil moisture. Cirrus clouds 17 .PREDICTIONS will soon become uninsurable’ (quoted in The Guardian. the lifetime of clouds and their thickness. breaks down the peaty soil allowing it to release stored carbon into rivers. or one third. David Stainforth of Oxford University warns of the possibility of a 12 C rise by the end of the century.9 billion by 2050. Recent research shows that DOC in Welsh rivers has increased 90 per cent since 1988.
According to Professor Beerling of Sheffield University: ‘Methane is being produced in increasing amounts thanks to the spread of agriculture in the tropics. Up to now the focus has been on limiting CO2 emissions almost to the exclusion of other greenhouse gases. At the present time it is cattle. This leaves a distinct isotope pattern which gives an indication of the sea temperature at a given time. 45–47).000 MILLION TONNES) USA EU China Russia Japan India +++ ++ 1990 2002 1994 only 6000 Figure 2. according to the UN. In the Eocene epoch 50 million years ago there was a catastrophic rise in temperature with seas 12 C warmer than today. At the time the Earth was carpeted with wetlands which produced high levels of methane which led to runaway warming. Another cause for concern stems from research finding from the Universities of Sheffield and Bristol. Rice is a particularly intensive source. different countries are making progress or otherwise in cutting their CO2 emissions.4 CO2 emissions by principal nations (UNFCCC 2004) 3000 4000 5000 1000 2000 0 ++1999+++2001 (both China figures include Hong Kong) SOURCES: UNFCCC (China figures from IEA) 18 . It transpires that this was due to emissions of methane. With a predicted steep rise in emissions from transport over the next decades. The evidence comes from oxygen trapped in the shells of marine fossils. United States Russia European Union Japan China India CO2 EMISSIONS (1. Evidence from plant fossils has shown that CO2 levels were similar to the present day and therefore could not have been responsible for that level of warming. 11 July 2004). pp. It should be noted that the improvement in the case of Russia is due to the collapse of its heavy industry since 1990 (Figure 2. It is time to spread the net more widely if there is not to be a rerun of the Eocene catastrophe. rice fields and termites which are major sources of the gas. 24 July 2004. It is expected that the next range of predictions by the IPCC due in 2007 will take account of feedback from cloud cover and produce significantly higher worst case temperature scenarios (from New Scientist. Car exhaust gases and nitrogen fertilisers are also increasing other gases’ (The Observer. ozone and nitrous oxide. all more powerful greenhouse gases than CO2. the latter point is a serious cause of concern.4). It is sobering to compare how.ARCHITECTURE IN A CLIMATE OF CHANGE are the most efficient at reflecting heat back to Earth and these are becoming more prevalent.
The only way it would be prepared to consider this kind if target is by carbon trading.. However.2 per cent globally based on 1990 levels. the most rapidly rising per capita emissions are occurring in Southeast Asia. p. Planting forests may look attractive but it presents three problems. However. an illegitimate recourse. Even more of a problem faces the USA.8 tonnes per person. As a first step on the path of serious CO2 abatement an accord was signed by over 180 countries in 1997 in Kyoto to cut CO2 emissions by 5. The average citizen in the North American continent is responsible for around 6 tonnes of carbon per year. The US has refused to ratify Kyoto but Russia has signed up which meant that the Treaty came into force in February 2005. members of the Royal Commission on Environmental Pollution. India and China. The US wants to use trees to balance its carbon books. Despite all the international conventions carbon dioxide emissions from developed countries are showing little sign of abating. Aviation’s share of the UK’s CO2 emissions will have increased four-fold by 2030. New Scientist. If aircraft emissions were also taken into account the situation would be substantially worse. One great anomaly is that air travel is excluded from the calculations of CO2. 7 August 2004. it all depends on the currency of exchange. since then it has enjoyed a significant economic boom with a consequent increase in CO2 emissions. The Department of Transport expects the numbers flying in and out of the UK to rise from 180 million in 2004 to 500 million in 2030 (reported in The Observer. To meet the Kyoto requirement it would now have to make a cut of 30 per cent. It has to be remembered that the UN IPCC scientists stated that a 60 per cent cut worldwide would be necessary to halt global warming. Though starting from a very low base. not. in itself. In 2003 there was a 1–2 per cent increase in CO2 emissions.5 per cent reduction target thanks to the gas power programme and the collapse of heavy industry. The UK was on track to meet its 12. these benefits have now been offset by the growth in emissions from transport.PREDICTIONS What is being done? The core of the problem lies in the disparity between the industrial and developing countries in terms of carbon dioxide emission per head. 22 March 2004). At the same time it should be noted that CO2 accounts for only one third of the global warming caused by aircraft (Tom Blundell and Brian Hoskins. The USA at twice the European average is still increasing its emissions which currently stand at 23 per cent of the world’s total. 19 . 24). later endorsed by the UK Royal Commission on Pollution. Kyoto set its reduction target against the 1990 level at 7 per cent. In Europe it is about 2. However.
8 per cent. Market forces are already powering the drive towards renewable energy in some industrialised countries. Overall. When you see oil companies investing in renewables then it must be the dawning of the realisation that saving the planet might just be cost effective.ARCHITECTURE IN A CLIMATE OF CHANGE First. Unfortunately there is not a reliable method of accounting for the sequestration capacity of a single tree let alone a forest. there have been attempts to equate the sequestration capacity of trees with human activities such as driving cars. releasing massive quantities of carbon into the atmosphere. Another problem recently exposed in the USA is that forests are inclined to burn down. This is mainly because growth in renewables will not keep pace with overall energy consumption. if governments and society fail to respond to the imperatives set by climate change. Technology and Climate Change Outlook’ offers an insight into a future still dominated by fossil-based energy. will increase their share of global CO2 emissions from 30 per cent in 1990 to 58 per cent in 2030. The last point refers back to the Hadley Centre prediction that there will be accelerating forest growth over the next 50 years. so. what they cannot escape is the inevitability of dramatic increases in the cost of fossil-based energy as demand increasingly outstrips supply as reserves get ever closer to exhaustion. then rapid die-back. China is the world’s second biggest emitter of greenhouse gases and the world’s biggest producer of coal. The reason for the difference is that there will be increasing use of coal as oil and gas prices rise and reserves. especially China and India. It predicts that CO2 emissions will increase by 2. It also estimates a fall in the share of energy from renewables from 13 per cent today to 8 per cent. In the final analysis.1 per cent per year for the next 30 years whilst energy use will rise by 1. five trees could soak up the carbon from an average car for one year. To meet its expected energy needs China plans to nearly treble its output from coal fired power stations by 20 . or 40 trees counteract the carbon emitted by the average home in five years. The report expects that energy use in the US will increase by 50 per cent and in the EU by 18 per cent over the same period. Developing countries. forests could possibly end up huge net contributors to global warming. The outlook for energy A report published in May 2004 from the European Union called ‘World Energy.
‘the kind of growth rates to which oil consuming countries are committed appear to be generating the demand for oil well above the underlying growth in the rate of supply .5 UK oil and gas reserves to 2020 (Association for the Study of Peak Oil and Gas 2004) 21 . So. the major reserves are located within countries that do not have a good record of stability. all appear to be past their production peaks’ (The Guardian. By 2020 the UK will be importing 80 per cent of its energy based on the current rate of consumption.0 4. As the economies of the world power ahead on the back of fossil fuels. which. with cities like Shanghai growing at an exponential rate. According to Stephen Lewis. The histogram in Figure 2. as a developing country.5 Gas 4. Oil consumption has doubled in the last 20 years and now stands at 80 million barrels per day. the spectre of diminishing reserves heightens anxieties within the corridors of government.5 3. an all time high.5 2.0 Already produced Future production Gas-Possible Oil-Possible Gas-2P Oil-2P 1967 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 2006 2009 2012 2015 2018 Figure 2. it is not required to do.5 0. . The North Sea reserves are already diminishing with a 5. There are conflicting estimates. As regards gas.PREDICTIONS 2020. but petroconsultants who advise the government claim that only one new barrel of oil is discovered for every four that are used. .0 2.0 1. .5 1. 9 August 2004).5 indicates the rate of decline of UK reserves of both oil and gas. Their estimate is that we are only two years away from the peak of oil production. for decades to come. the Middle East. the North Sea . The oil companies estimate that reserves will be exhausted within about 40 years but that is not so much the prime issue.5 Oil Oil equivalent (mmboe/day) 3. China is virtually ruling out measures to mitigate its CO2 emissions. . City economic analyst. the US. These new power plants are not being constructed to accommodate future CO2 sequestration equipment and they are likely to be in service for 50 years.0 0.
Even without including the prospects for China the current demand for oil worldwide is growing at 2 per cent a year. Beyond 2008. that both gas and oil worldwide will peak around 2008 (Figure 2. Campbell says we are ‘at the beginning of the end of the age of oil’. These states account for 35 per cent of the market. the point at which it is considered they are able to control prices at a time of rising demand. or even war. Iran and Nigeria (Ministry of Defence. For the US the Department of Energy estimates that imports of oil will rise from 54 per cent in 2004 to 70 per cent by 2025 due to its declining reserves and increasing consumption. Oil geologist Colin J. in particular the UK. The Chinese economy is growing at 8–10 per cent a year. 90 per cent of the UK’s gas will come from Russia. especially by developing countries on the rapid road to developed status. He predicts that after 2005 there will be serious shortages of supply with steeply rising prices and by 2010 a major oil shock reminiscent of the 1970s except that then there were huge reserves to be tapped. in a graph published on the website of the Association for the Study of Peak Oil (ASPO). By 2020 it is estimated that there will be one billion cars on the world’s roads. An updated 2004 scenario for world peak oil production by Colin Campbell shows.ARCHITECTURE IN A CLIMATE OF CHANGE life expectancy of 15–20 years. where it is expected that its North Sea fields will be exhausted by 2016. 2 March 2000). The Kuwait episode then the Iraq war should remind us of the sensitivity of the situation. In no time there will be one person in 50 then perhaps one in 20 owning a car.6). increasing price volatility for both oil and gas seems inevitable. The government was warned that another oil price shock could trigger a stock market crash. The government has acknowledged that. It has joined the World Trade Organisation and opened its markets to international trade which gives additional impetus to economic growth. According to the environmental policy analyst Dr David Fleming it is ‘not possible that we can survive without a dramatic increase in the price of oil’ (The Guardian. At the same time petrol geologists estimate that production of oil will peak in the first decade of 2000 and then output will decline by 3 per cent a year. 8 February 2001). In the oil shocks of the 1970s we were extricated from long-term pain by the discovery of large oil reserves in the North Sea and Alaska. Add to this the fact that at least half the remaining global reserves will be located in five autocracies in the Middle East who have already demonstrated their ability to manipulate prices causing the oil shocks of the 1970s. 22 . There are still large reserves but they are located in places like the states around the Caspian basin which Russia regards as its sphere of influence – not much comfort to the west. The world is one huge combustion engine which consumes 74 million barrels of oil a day to keep it running for now! At the present time in China one person in 125 has a car. by 2020. This time there are no escape routes.
renewables.East Heavy etc. Environment Data Services have described them as ‘heroically optimistic’. in 2008 the EU will enforce desulphurisation regulations on coal fired plants making them uneconomic. All but two of the Magnox stations have closure dates before 2008. Recently questions have been raised about the government’s estimates of future generation capacity within the nuclear industry. The pressurised water and gas cooled reactors have been beset with problems. After that.6 World oil and gas production to 2050 Coal 16 per cent Nuclear 16 per cent Renewables 10 per cent Gas 57 per cent. The projected fuel mix for the UK in 2010 is: ● ● ● ● Figure 2. However.. a verdict which therefore also applies to the government’s target of 20 per cent reduction in CO2 emissions by 2010 since that target assumes full bore production by its ageing reactors. As we have noted gas has its uncertainties. gas generation and possibly a new batch of nuclear generators will fill the vacuum. A plant 23 .PREDICTIONS 35 US-48 30 Billion barrels a year (Gb/a) 25 20 15 10 5 0 1930 Russia Europe Russia Other M. The use of biofuels may offer a future for coal fired power stations. the creaking nuclear industry will operate at full capacity with an unprecedented rate of efficiency. for the next decade. In fact nuclear output dropped 4 per cent in 1999 and 10 per cent in 2000 and in the latter year coal fired generation was up 13 per cent. The DTI’s energy predictions assume that.
The obvious conclusion to draw from all this is that buildings being designed now will. The pressure to incorporate the external costs like damage to health. By 2015 the UK could be facing an energy vacuum which emphasises the need to take the plunge into renewable technologies as a matter of urgency. say. by then. demand will probably have increased by more than this percentage and. many of the nuclear power plants are likely to have been decommissioned.ARCHITECTURE IN A CLIMATE OF CHANGE operated by Biojoule in East Anglia is already producing 15 000 tonnes a year of specially processed wood for partial fuel replacement in coal fired power plants. It states that within the European Union the share of renewable electricity rose from 12 per cent in 1990 to 14 per cent in 2001. at the same time. in most cases.. ten years’ time. still be functioning when the screws on fossil fuels are really tightening. it will be impossible to make accurate predictions as to running costs in.7 Comparison of electricity derived from renewables in 25 EU states 0 . What is certain is that energy prices will rise steeply since there is still only patchy evidence of the will to stave off this crisis by the deployment of renewable energy technologies. For buildings wholly reliant on fossil-based energy. buildings and above all the biosphere into the price of fossil will intensify as the effects of global warming become increasingly threatening. The government undertaking is to meet 10 per cent of electricity demand by 2010 from renewable sources. What tends to be overlooked is. a European Environment Agency Update on selected issues. (Figure 2. The EEA has produced a histogram which shows the relative performance of member states.7) (EEA 2004. 25 . Copenhagen.PREDICTIONS by 2010. May 2004).
Earthscan 2002. July 2003).6 million tonnes of oil equivalent (mtoe). even exceed. Hermann Scheer. The Solar Economy. this capacity without help from nuclear? This is a key question since the Energy White Paper of February 2002 put nuclear on hold pending a demonstration that renewables could fill the void left by the decommissioning of the present cluster of nuclear facilities.7 mtoe (UK Energy in Brief. Is it fantasy to support that renewable energy sources could equal. 7 The UK energy picture In 2002 total inland energy consumption in the UK was 229. DTI. Oystein Dahle.Chapter Renewable Three technologies – the marine environment Two quotes set the scene for this chapter: A sustainable energy system is probably the single most important milestone in our efforts to create a sustainable future . p.3 mtoe to the total. . Decarbonisation of the energy system is task number one.4 per cent for renewables by 2010 and an aspiration to achieve 20 per cent by 2020. The government has declared a target of 10. . . Chairman. Renewables and energy from waste accounted for a mere 2. Nuclear contributed 21.
xi). Government claims that energy suppliers operate within the framework of a free market and on a level playing field is based on flawed economics.RENEWABLE TECHNOLOGIES – THE MARINE ENVIRONMENT suppliers. We have the bizarre situation that a highly subsidised. being relatively high capital cost but low running cost technologies. will be exhausted sooner rather than later. According to Hermann Scheer this would threaten the long-term ambitions of the power industry which sees the prospect of ultimately controlling information transmission as well as energy. In contrast. it concludes that the real cost of electricity from coal and oil is about double the current economic cost to the producers. The problem is that renewables with their high investment costs violate one of the founding laws of accountancy that investors want a high return on capital in the short term. Only now is it being widely realised that reserves. ‘They hold all the cards they need to construct a comprehensive commodity supply and media empire’ (ibid. At the same time the market pays scant regard to its environmental responsibilities. Never has it been more apparent that oil and gas are high risk commodities that can have a powerful negative impact on the Stock Index due to price volatility. This is the market situation in which renewables have to compete and it constitutes a sharply tilted playing field in favour of the fossil fuel industries. The European Commission’s ExternE project has sought to quantify the externalities. This is clearly an abuse of the 27 . the 20 per cent threshold may well be regarded as the ‘red line’ beyond which they will be forced to run on less than full capacity. Beyond this percentage the grid would have to be reconfigured to encompass extensive distributed generation. p. Repayment of capital and operating costs are largely fixed and so represent a low risk. The anomaly is that the cost–benefit system employed here ignores the element of risk. The results should make it possible more accurately to calculate life-cycle environmental costs. As far as the major power distributors are concerned.. The New Elements for the Assessment of External Costs from Energy (NewExt) is refining the methodology to provide more accurate information and was due to report in 2004. especially that of driving up global warming.. as recommended by the Royal Commission on Environmental Pollution (ibid. at the same time compensating for fluctuations in the supply from renewables. For example. For gas generated electricity the shortfall is about 30 per cent. One of the key factors favouring the big suppliers is the web of direct and indirect subsidies which the industry enjoys such as the fact that its raw material is regarded as being a free gift from nature. are not nearly so affected by macroeconomic shifts such as the international price of oil or the Stock Index. For some reason energy is not subjected to the normal rules of financial risk assessment in determining the market value of the commodity. renewables. 60). high risk energy stream is stifling the almost zero risk renewable systems that draw on solar and lunar energy and are therefore not reliant on a continual input of an extracted fuel. apart from coal. highly polluting. p.
hydroelectricity from the damming of rivers. the most capital intensive form of energy. mostly soil. tidal currents and waves. Work started in 1960 to create the huge Lake Nasser as the storage facility and as a potential irrigation source for a major part of the country. from the Ethiopian highlands. It involves damming a watercourse to create the necessary pressure to drive high speed impulse turbines. If the contours of the energy playing field really were level. the dam has so disrupted the flow of the Nile that it threatens the agriculture of the delta. part of which used to be deposited in the Nile flood plain. It cost $1 billion ($10 billion at current prices) and began operations in 1968. This chapter focuses on the first and second technologies. The project has served to illustrate some of the problems which accompany hydroelectric schemes of this massive scale. the Egyptian President. on the one hand. For example. third. One of the first major projects to be completed after the Second World War was the Aswan Dam scheme initiated by Colonel Nasser. but. and the country is considering reactivating storage schemes beyond its borders. then these anomalies must be corrected if a decarbonised electricity infrastructure is to be a reality. Since it seems inevitable that renewables will have to fight their corner in a free market for an indefinite period. Energy can be derived from water according to four basic principles: first. on the other. Hydroelectric generation Hydroelectric schemes which exploit height difference in the flow path of water are the oldest method of generation from water. delivering 2000 megawatts (MW) of power. At the same time. is now trapped behind the dam. offers the longest-term energy certainty coupled with the highest energy density. the extraction of hydrogen from water via electrolysis. Energy from rivers and seas Energy extracted from the marine environment is. a fact which is calculated to have done irreparable damage to the fertility of the Nile valley and delta. A further problem is that. 28 . the Nile has conveyed millions of tonnes of silt per year. The silt. second. the dynamics of thermal difference. evaporation from the lake has been much greater than anticipated. then renewables would offer excellent investment opportunities. and fourth. from hydrodynamics or the movement of water by virtue of tidal rise and fall. historically. To compensate for the loss Egypt is now one of world’s heaviest users of agricultural chemicals.ARCHITECTURE IN A CLIMATE OF CHANGE term ‘free market’. The Boulder Dam scheme in the USA was the first large-scale project implemented in the 1930s as a means of driving the country out of recession.
With the exception of projects on the River Danube. 29. In December 1994 work commenced on the Three Gorges scheme on the Yangtze River. Given the right buying-in rates from the National Grid.75 m per second which makes them eligible to power so-called run of river generators.RENEWABLE TECHNOLOGIES – THE MARINE ENVIRONMENT One of the worst drawbacks concerns saline pollution. Ch. in Sweden it is 50 per cent of the total and Scotland produces 60 per cent of its electricity from non-fossil sources. the Itaipu Dam in Paraguay. ‘Run of river’ systems Many rivers have a flow rate in excess of 0. plans were revived to generate up to 37 000 MW along the course of Mekong River. Most of Norway’s supply is from hydro sources.F. Small-scale hydro In small-scale projects water is usually contained at high level by a dam or weir and led down a pipe (penstock) or channel to a generator about 50 m below to create the necessary force to drive the generator. 28–32.’ in Sustainability at the Cutting Edge. In return the country will receive 18 000 MW of power which is 50 per cent more than the world’s existing largest dam. The dam is two kilometres long and some 100 metres high. Even so. in November 1994. Europe gains most of its hydroelectricity from medium to small-scale plants. again with drastic potential social consequences. 7 May 1994). (2002) ‘Small-scale hydro. such ventures could become a highly commercial proposition. mostly hydro. pp. The conventional method is to create a dedicated channel which 29 . p. Large areas of fertile land are being threatened by the salt which makes the ground toxic to plants and ultimately causes it to revert to desert. ‘The UK has a considerable untapped small-scale hydro resource’ such as the discreet plant at Garnedd in Gwynedd. Architectural Press). It has created a lake 600 kilometres long displacing over one million people. 29 June 1991) (further information in Smith. North Wales. In addition. According to the Department of Trade and Industry. An intermediate technology version has been designed for developing countries in which a standard pump is converted to a turbine and an electric motor to a generator (New Scientist. There is now a project to remove saline water from two million hectares of land at a cost which exceeds the original price of the dam (New Scientist. Salts are dissolved in river water and modern irrigation systems leave salts behind – about one tonne per hectare. 10. in the long term this dam will make a relatively small impact on China’s dependency on fossil fuel. P.
it could also be situated in channels with a high tidal flow which are too shallow for other types of tidal turbine. The British Isles benefit from some of the 30 . A Norwegian company. The wings are continuously adjusted by computer monitoring to keep them at their most efficient angle. issue 1/04) accommodates a cross-flow generator which is a modern version of a water wheel or a ‘Kaplan’ turbine which has variable blades.1).ARCHITECTURE IN A CLIMATE OF CHANGE Figure 3. Not only could this system capture the energy of many rivers. It is claimed that the water turbine converts 50 per cent of the energy in the water to electricity with a theoretical maximum of 59 per cent.1 WPI turbine (courtesy of CADDET. has developed a water turbine on floats that has a vertical axis rotor fitted with blades shaped like an aircraft wing. Assuming a steady flow of water with a velocity of 3 m/s and a regularity of 96 per cent a 15 m diameter 500 kW turbine would produce 4 million kWh/year. Tide levels can be affected by storm surges as experienced dramatically in the UK in 1953. Water Power Industries (WPI). The ‘waterfoils’ are vertical and the flow of a river creates negative pressure which causes the wheel to rotate (Figure 3. Tidal energy Tidal energy is predictable to the minute for at least the rest of the century.
Suffolk. A further study was completed in 1945 and the latest in-depth investigation was concluded in 1981. A Royal Commission was formed in 1925 to report on the potential of the River Severn to produce energy at a competitive price. the French government elected to concentrate its generation policy on nuclear power which accounts for about 75 per cent of its capacity. The only operational barrage in Europe is at La Rance. Power generation is obviously intermittent but the spread of tide times around the coasts helps to even out the contribution to the grid. In all cases the verdict was positive. it generates on both the flow and ebb tides. In summary. Normandy. 31 . In the first quarter of the twentieth century this principle was applied to electricity generation in the feasibility studies for a barrage across the River Severn. A medieval tide mill is still in working order in Woodbridge. Tidal power works on the principle that water is held back on the ebb tide to provide a sufficient head of water to rotate a turbine. there are at least four technologies that can exploit the action of the tides. Dual generation is possible if the flow tide is also exploited.RENEWABLE TECHNOLOGIES – THE MARINE ENVIRONMENT greatest tidal ranges in Europe. Since then the technology has improved including a doubling of the size of generators. It is a bidirectional scheme. The tidal barrage Trapping water at high tide and releasing it when there is an adequate head is an ancient technology. It reported in 1933 that the scheme was viable.. that is. They are: ● ● ● ● The tidal barrage The tidal fence or bridge Tidal mills or rotors Impoundment. Two-way operation is only beneficial where there is a considerable tidal range and even then only during spring tides. Despite this supporting evidence the UK still shows reluctance to exploit this source of power. offering reliable electricity in the multi-gigawatt range. Despite its success as a demonstration project. This increases the volume of water passing through the barrage by the square. Annual production at La Rance is about 610 gigawatt hours (GWh). though the last report was cautious about the cost/benefit profile of the scheme in the context of nuclear energy.
schemes proposed in the UK have been one directional. The principle is that water is held upstream at high tide until the downstream level has fallen by at least 2. It is a modular technique with turbine caissons constructed on slipways or temporary sand islands.0 metres. The technology of barrages was transformed by the caisson techniques employed in the construction of the Mulberry Harbour floated into place after D-Day in the Second World War. generating only on the ebb tide. non-polluting source of energy. According to the Department of Trade and Industry’s Energy Paper Number 60. Tidal barrages can assist with the local infrastructure of the region.2).2 Basic tidal barrage Up to now. The DTI report concludes: There are several advantages arising from the construction of tidal barrages in addition to providing a clean. The upstream volume of water is supplemented by pumping additional water from downstream on the flood tide. it has about half of all the European Union’s tidal generating potential of approximately 105 terawatt hours per year (TWh/y) (ETSU).ARCHITECTURE IN A CLIMATE OF CHANGE Figure 3. This is reckoned to be more cost effective than bidirectional generation in most situations (Figure 3. November 1992: ‘The UK has probably the most favourable conditions in Europe for generating electricity from the tides. create regional development 32 .’ In fact.
Since rivers are now appreciably cleaner than in the 1970s. However. A further complication is the Thames Gateway project which includes 120 000 new homes below sea level. an alternative to a barrage which can also deliver massive amounts of energy at less cost/kWh. China has 500 possible sites with a total capacity of 110 000 MW. the threat from rising sea level was hardly a factor in the 1970s. The Guardian. The economic argument could be countered if the market corrections stated earlier were to be implemented. it is a gold mine. The Thames is claimed to be the cleanest river in Europe. low running cost technology.’ In 1994 the government decided to abandon further research into tidal barrages for a variety of reasons ranging from the ecological to the economic. a leading tidal expert in the UK. A group of engineering companies has renewed the argument in favour of the River Severn barrage. namely. however. generate multi-gigawatt power for the capital (Figure 3. One of the arguments against tidal barrages is that they would trap pollution upstream. sums up the situation by saying that a tidal power scheme may be expensive to build. but it is cheap to run. this should not now be a factor.3). the tidal fence or 33 . at the same time. In the year 1986/87 the barrage was not closed once against tidal and river flooding. If one flood breaks through the Thames Barrier it will cost about £30 billion or roughly 2 per cent of GDP (Sir David King. playing host to salmon and other desirable fish species. The tidal fence There is.RENEWABLE TECHNOLOGIES – THE MARINE ENVIRONMENT opportunities and provide protection against local flooding within the basin during storm surge. it was decided that London should be protected by a barrage. thanks largely to EU Directives. Around the world numerous opportunities exist to exploit tidal energy. All this combines to make a strong case for an estuary barrage that will protect both the Thames and the Medway and. 9 January 2004). indicating that it would meet 6 per cent of Britain’s electricity needs whilst protecting the estuary’s coastline from flooding (New Scientist. another concern has grown in stature. notably in the Bay of Fundy in Canada where there is a proposal to generate 6400 MW. ‘After a time. the threat from rising sea level amplified by an accelerating rate of storm surges. It was designed in the 1970s to last until 2030. However. Professor Eric Wilson. storm surges and increased rainfall and river rundown well before that date. In market terms a normal market discount rate heavily penalises a high capital cost. now it is a major cause of concern that the barrage will be overwhelmed by a combination of rising sea level. in 2001 it closed 24 times. Following the 1953 floods. long life. Government Chief Scientist. namely. 25 January 2003).
The generators are housed in the box structure bridge element which can also serve as a highway or platform for wind turbines (Figure 3. They can function within a tidal regime of at least 1. The rotors are 10. The slow rotation of the turbines poses minimum risk to marine life. Multiple Darrieus rotors capture energy at different levels of the tide. At the same time the system allows for the free passage of silt.5 m in diameter and rotate at 25 rpm. consists of modular shell concrete marine caissons linked to form a bridge.4). each turbine having a peak output of up to14 MW.75 m.. In terms of energy density. the tidal fence outstrips other renewable technologies: Wind 1000 kWh/m2 Solar (PV) 1051 kWh/m2 Wave 35–70 000 kWh/m2 Tidal fence 192 720 kWh/m2 (Source: Blue Energy Canada Inc. for example as designed by Blue Energy Canada Inc. It is a four-phase project with the first phase comprising a 4 kilometre tidal fence between the islands of Dalupiri and Samar in the 34 . Vertical axis Davis Hydro Turbines are housed between the concrete fins. with large marine mammals protected by a fence with a backup of an automatic braking system operated by sonar sensors. From the ecological point of view the system has the advantage over the barrage option of preserving the integrity of the intertidal zones.3 River Thames flood risk zones below 5m contour and suggested barrage bridge which has only recently come into prominence.) Blue Energy has designed a major installation at Dalupiri in the Philippines. Wading birds have nothing to fear.ARCHITECTURE IN A CLIMATE OF CHANGE 5 miles Barrage Thames Barrier Figure 3. The tidal fence system.
4 Blue Energy tidal fence concept San Bernardino Strait.) (1996) Renewable Energy – Power for a Sustainable Future. The structure is designed to withstand typhoons of 150 mph and tsunami waves of 7 m. The British Isles offer considerable opportunities for the application of this technology. The estimated maximum capacity of the 274 turbines housed in the tidal fence is 2. cites data from the DTI 1999 and the RCEP 2000.5 GW as defined in the first of four scenarios Many of these are intermittent and unpredictable.2 GW guaranteeing a base daily average of 1. An exception is tidal energy which is predictable and this is where the tidal fence comes into its own. The Tyndall paper suggests that the optimum output from renewables is 136. On the assumption that 35 .RENEWABLE TECHNOLOGIES – THE MARINE ENVIRONMENT Figure 3.1 GW. by Jim Watson which. The data which are used here have been extracted from a paper from the Tyndall Centre in the University of Sussex. G. UK ‘Electricity Scenarios for 2050’ Working paper 41. 2004. (ed. The Open University Renewable Energy Team has selected 17 estuary sites suitable for medium to large-scale barrage systems (Boyle. Oxford University Press). in turn. The potential for the UK Many speculations have been offered regarding the ultimate generating potential of various renewable technologies. Blue Energy has already identified the Severn estuary as a suitable site.
However. This is based on an extrapolation from the Dalupiri scheme and is therefore only a rough estimation. or about 7 GW. The installed cost at present is estimated to be US$1400 per kW. It is still at the development stage and its final manifestation will operate in streams in both directions. it is an appropriate system to combine with pumped storage to even out the sinusoidal curves. they add up to a linear capacity of 208 km. Tidal currents The European Union has identified 42 sites around the coasts of the UK which have sufficient tidal velocity to accommodate tidal turbines. With a load factor of 0. It is estimated that tidal stream energy has the potential to meet one quarter of the electricity needs of the UK which amounts to about 18 GW. it should be enough to cause a reappraisal of the tidal potential of the UK. According to Blue Energy they have the potential to generate 26 GW or more than one third of the UK’s generating capacity. They operate at a minimum velocity of about 2 m/s.50. However. including the Stingray project which exploits the tidal currents to operate hydroplanes which oscillate with the tide to drive hydraulic motors that generate electricity. underwater turbines are subject to much less buffeting than their wind counterparts. The tidal fence vertical turbine is claimed to be ideal for tidal streams since it has multiple rotors which can capture tidal energy at different depths. of the UK’s electricity demand. 36 .5 knots. If only half of the full estuary width were available to house turbines in each case. The tidal mill Horizontal axis turbines are similar to wind turbines but water has an energy density four times greater than air. The hydroplanes are profiled like an aircraft wing to create ‘lift’. There are several technologies being researched. the most likely technology to succeed in the gigawatt range are the vertical or horizontal turbines. the greatest potential source of tidal currents is located off the islands of Guernsey. Since the output from the tidal fence is predictable and peak output may not coincide with peak demand from the grid. especially as the cost is highly competitive. The minimum velocity of tidal flow to operate a tidal fence is 1. A 1993 DTI report claimed that the Pentland Firth alone could provide 10 per cent. Since the tidal flow is constant. which means that a rotor 15 m in diameter will generate as much power as a wind turbine of 60 m diameter. this technology would deliver 9 GW. However. The strength of the current tends to be strongest near the surface so a vertical series of rotors could accommodate the different speeds at various depths. An ideal site could be the Pentland Firth. this would produce a peak output of about 60 GW and a daily average of 30 GW.ARCHITECTURE IN A CLIMATE OF CHANGE these sites would be equally suitable for tidal fences.75 m/s or 3.
sand and gravel similar in appearance to standard coastal defences. serviced above water According to Peter Fraenkel.5 Tidal stream turbines or tidal mills. According to Tidal Electricity Ltd. The system is ideal for situations in which there is a significant tidal range and shallow tidal flats encountered in many coasts of the UK. His company has built a 300 kW demonstration turbine off the Devon coast and has a project for a turbine farm in the megawatt range (Figure 3. This company is presently investigating the opportunities around Guernsey and Alderney.RENEWABLE TECHNOLOGIES – THE MARINE ENVIRONMENT Figure 3. The system consists of a circular barrage built from locally sourced loose rock. It is divided into three or more segments to allow for the phasing of supply to match demand. the best tidal stream sites could generate 10 MW per square kilometre. Director of Marine Current Turbines. Offshore impoundment An alternative to estuary tidal generation is the concept of the tidal pound. computer simulations show 37 . The idea is not new as mentioned earlier.5).
wind power. This is perceived as a cost-effective technology thanks in part to the extra revenue from the Renewables Obligation Certification.’ It has been estimated that impoundment electricity could meet up to 20 per cent of UK demand at around 15 GW. The first inshore version in the UK was positioned on an inlet in the Scottish Isle of Islay (Figure 3. It is relatively unobtrusive and much kinder to marine life than a tidal barrage. It offers predictable power with a load factor which is significantly better than.3 GW. and is already contributing 500 kW to the grid. In total the potential capacity of the various technologies that exploit the tides around Britain is in the region of 65 GW. 38 . The variation in high water times around the coasts coupled with pumped storage help to even out the peaks and troughs of generation before any account is taken of the range of other technologies. The life expectancy of the structure is 100 years. There are both inshore and offshore versions either in operation or projected. This is a popular holiday coast and it is expected that the project will become an important visitor attraction. Besides having the potential to generate substantial amounts of electricity. . In its Memorandum submitted to the House of Commons Select Committee on Science and Technology this company claimed that ‘The UK has very large tidal ranges and many suitable for sites . The World Energy Council estimates that wave power could meet 10 per cent of world electricity demand. Tidal pounds would be fitted with low-head tidal generating equipment which is a reliable and mature technology. It should generate 432 MW. Because it is located in shallow water construction costs are much less than for barrage systems. With a load factor of 0. tidal pounds can also provide coastal flood protection which was an important factor in determining the viability of the first largescale project in the UK off the North Wales coast. The pound will be about 9 miles wide and 2 miles deep and located a mile offshore. The tidal barrage at La Rance in Normandy attracts 600 000 visitors a year. The most favoured system uses the motion of the waves to create an oscillating column of water in a closed chamber which compresses air which. In 1990 Towyn near Rhyl experienced devastating floods. drives a turbine. that could conceivably generate thousands of megawatts.62 this amounts to 9.50.6). There is talk of added attractions like a sea-life musuem and an education centre. for example.ARCHITECTURE IN A CLIMATE OF CHANGE that a load factor of 62 per cent can be achieved with generation possible 81 per cent of the time. . giving a reliable output of about 9 GW. in turn. Wave power Wave power is regarded as a reliable power source and has been estimated as being capable of meeting 25 per cent or 18 GW of total UK demand with a load factor of 0.
The joints between the cylinders contain pumps which force oil through hydraulic electricity generators in response to the rise and fall of the waves. The success of this pilot project justified the construction of a full-scale version which is now in operation. Two turbines are driven by positive pressure as air is compressed by incoming waves. Belfast. It is estimated to produce 750 kW of electricity. Ocean Power Devices (OPD). The plant 39 . Like Scotland. The head of water is sufficient to operate a conventional hydroelectric power plant with a capacity of 370 kW. Currently under test in the Orkneys is a snake-like device called Pelamis which consists of five flexibly linked floating cylinders. It is rated at 500 kW which is enough to power 200 island homes. A large-scale version of this concept is under construction on the south coast of Java in association with the Norwegians. A 25 metre slit has been cut into the cliffs facing the north Atlantic at Portnahaven to accommodate a wave chamber inclined at 45 degrees to the water.RENEWABLE TECHNOLOGIES – THE MARINE ENVIRONMENT Figure 3. and negative pressure as the receding waves pull air into the chamber. Norway enjoys an enormous potential for extracting energy from waves. and has an output of 75 kW which is fed directly to the grid.6 Principle of the Isle of Islay OWC wave generator It was designed by Queen’s University. The manufacturer.7).5 m diameter. This lifts the sea water about 4 m depositing it into a 7500 m2 reservoir. This consists of a 60 m long tapering channel built within an inlet to the sea. The narrowing channel has the effect of amplifying the wave height. each of 3. Twenty such farms would provide enough electricity for a city the size of Edinburgh. As far back as 1986 a demonstration ocean wave power plant was built based on the ‘Tapchan’ concept (Figure 3. claims that a 30 MW wave farm covering a square kilometre of sea would provide power for 20 000 homes. The rather clever Wells turbine rotates in one direction in either situation.
the ‘Tapchan’ will have a capacity of 1. could come to about 74 GW. The total for the three tide and wave technologies. taking account of load factors. tidal stream and tidal barrage of around 16 GW.7 Wave elevator system. The Tapchan plant is able to cope with extremes of weather. This amounts to more than twice the present electricity generating capacity of the UK.) for wave. the total comes to about 193 GW. 40 . The plant is totally pollution free. It will produce cheap electricity for remote islands. cit. The main mechanical components are standard products of proven reliability.1 MW.ARCHITECTURE IN A CLIMATE OF CHANGE Figure 3. If we substitute these figures for the quantities indicated in Jim Watson’s paper (op. Maintenance costs are very low. It is unobtrusive. and add the remaining renewable technologies from this source amounting to 119 GW taking account of load factors. As a system this has numerous advantages: ● ● ● ● ● ● ● The conversion device is passive with no moving parts in the open sea.
this would require an immediate policy decision by the government to make a quantum leap in its investment in renewable technologies. What is needed is cross-party political support so that the subject of renewable energy is removed from the cut and thrust of politics. wave energy and tidal power. There is no doubt that the UK has the natural assets to enable it to be fossil fuel free in meeting its electricity needs by 2030. especially the range of opportunities offered by the tides. 41 .RENEWABLE TECHNOLOGIES – THE MARINE ENVIRONMENT The other part of the equation is the demand side and Watson’s scenarios include a reduction in electricity demand of up to one third. even if half the natural assets of the UK are exploited to produce carbon-free electricity. . Some of the best marine renewable resources in the world – offshore wind.’ This chapter suggests a ‘road map’ that would enable actions to be matched to words. This could provide further backup capacity from megawatt grid connected fuel cells in addition to fuelling the growing population of hydrogen powered road vehicles expected over the next decade. . The logical use for this surplus capacity is to maximise pumped storage and to create hydrogen from electrolysis. We have many strengths to draw on. Tidal energy could more than fill the void in supply left by the demise of nuclear. It has been estimated that converting transport to hydrogen would require 143 GW of electrical power to extract hydrogen from water via electrolysis. However. this leaves an appreciable margin of supply over demand. Assuming significant gains in energy efficiency. In his ‘green speech’ in March 2003 Prime Minister Blair stated that he wanted Britain ‘to be a leading player in this green industrial revolution .
Besides offering a direct source of energy. The sun is the primary source of renewable energy. waves. This will be considered in detail in later chapters.5 million tonnes per year in the UK alone by the year 2025 (DOE Energy Paper 60). 42 . cooling and lighting. More detailed explanations will appear later. However.Chapter Renewable technologies – Four the wider spectrum Whilst Chapter 3 has focused on marine renewable technologies with special emphasis on the UK. It is particularly appropriate as an energy source for buildings. tides (together with the moon) and a host of biological sources. it drives the Earth’s climate creating opportunities to draw energy from wind. The following paragraphs are by way of an introduction. Because it displaces the use of fossil fuel it is estimated that passive solar design could lead to a reduction in carbon dioxide (CO2) amounting to 3. the intensification of the global warming debate has led to increasing pressure to design buildings which make maximum use of free solar gains for heating. Communities in a situation where there are high levels of insolation can benefit from technologies not viable in temperate climes. Active solar This term refers to the conversion of solar energy into some form of usable heat. In temperate climates the most practical application of solar radiation is to exploit the heat of the sun to supplement a conventional heating system. this chapter scans more widely to include the opportunities that occur in different climates. Passive solar energy Advocates of passive solar design have been around for many decades and the prize-winning schemes in a European competition for passive solar housing mounted in 1980 show that the technology has not advanced significantly since that time.
Air blown through its honeycomb structure reaches 680 C. where the temperature would be near the ambient level.RENEWABLE TECHNOLOGIES – THE WIDER SPECTRUM Solar thermal electricity In areas where there is substantial sunshine. The project has demonstrated the viability of the principle and plans are being drawn up for a giant version in Mildura. would be used to grow food. pp. 42–45). The scheme would carry low maintenance costs and would have a life expectancy of 100 years. with a 195 metre tower served by a greenhouse collector 240 metres in diameter. solar energy can be used to generate electricity in a number of ways. The hot air travels down the absorber tower to a heat exchanger where it generates steam to drive a conventional turbine. In essence it produces superheated steam to drive a turbine. One method which has been successfully demonstrated is the solar chimney. A prototype has been built in Manzanares. Designed primarily for desert locations it consists of a tall column surrounded by a glass solar collector. The collector warms the air by around 17 C creating an updraught of 12 metres per second giving an output of 50 kilowatts (Figure 4. The air is heated by the circular greenhouse and drawn through the chimney which acts as a thermal accelerator. This is why the area has been chosen to demonstrate another technology for producing electricity called the SolAir project. The system produces up to 1 megawatt of electricity. 31 July 2004. The updraught would be about 15 metres per second or 54 km/hr and will drive 32 turbines at the base. A lookout gallery at the top of the tower promises to be a not-to-be-missed tourist attraction (see New Scientist.1). The idea has been made possible by the development of ceramics that can tolerate high temperatures. Within the chimney are one or more vertical axis turbines. The surface of the absorber reaches 1000 C. At ground level 300 large mirrors or heliostats each 70 m2 track the passage of the sun and focus its rays on a silicon carbide ceramic heat absorber. each 15 to 20 times larger than the demonstration plant and together generating hundreds Figure 4. Spain. Australia. The plant would operate over night by using daytime heat to warm underground water pipes connected to an insulated chamber. In effect it is a chimney surrounded by a huge solar collector or greenhouse. The Almeria region of Spain is the sunniest location in Europe. The outer areas of the collector. Construction of the tower will consume an estimated 700 000 m3 of high strength concrete. achieving about 3000 hours of sun a year. The tower will be 1000 metres high with a solar collector of glass and plastic 7 kilometres across. According to the Spanish Ministry of Science: ‘In five to ten years’ time there should be several plants across Europe. returning heat to the surface of the collector during the night.1 Solar chimney generator 43 . The economics suggest that the tower would produce about 650 gigawatt hours per year or enough to serve a population of 70 000. The ceramic is also able to store heat to compensate for cloudy conditions.
The engine operates on the basis that the heat vaporises liquid sodium in its receiver at the focal point of the dish.6 MW for the grid which saves some 4500 tonnes/year of CO2. The expanding helium drives pistons which in turn drive an alternator to produce electricity (Figure 4. The concentrator mirrors produce about 30 kW of reflective power to the heat pipe receiver which is linked to the engine. 10 April 2004). One spin-off from this technology is a demonstration scheme which has attached 18 solar thermal power dishes to an existing coal fired steam turbine power station producing the equivalent of 2.2 Solar concentrator. An alternative solar concentrator built by the Australian National University uses a computer to enable it to track the sun with extreme accuracy. Egypt is also warming to the possibility of this new export opportunity. This system produces superheated steam in a solar boiler at the focal point. At current prices it is expected to produce electricity at one third the price of photovoltaics. Plans are already in place to locate these plants along the Algerian coast to export electricity to Europe. Abilene. The development Figure 4. The steam is piped to a four cylinder expansion engine that drives a 65 kVA generator. A version in the United States links this to a unique helium-based Stirling engine.‘Power of the midday sun’.2). Texas (courtesy of CADDET) 44 .ARCHITECTURE IN A CLIMATE OF CHANGE of megawatts’ (New Scientist. The parabolic solar thermal concentrator This is another option for sun-drenched locations which focuses the radiation to produce intense heat – up to 800 C. Condensation of the sodium on the heater tubes raises the temperature of an internal helium circuit.
as with the tides. In hot dry climates an ideal application for this system is in desalination. capable of only a relatively low output per unit of area. 91). it is. in certain countries such as the UK and Denmark. The uniqueness of PV generation is that it is based on the ‘photoelectric quantum effect in semi-conductors’ which means it has no moving parts and requires minimum maintenance. compact and mobile PV arrays can operate refigerators and water pumps. of course. as yet. Its disadvantages are that it is expensive. for example the rural hospital at Dire’ in Mali. climate and seasonal variation. As it produces DC current.RENEWABLE TECHNOLOGIES – THE WIDER SPECTRUM potential is to use the waste heat from the system for co-generation. The UK has the best wind regime in 45 . Already rural medical facilities are being served by PV arrays. PV technology will be considered further in Chapter 7. We are now seeing the emergence of large plants producing PVs on an industrial scale. One of the most promising systems for converting this solar radiation into usable energy is the photovoltaic (PV) cell. greater than in 2001. The result is that unit costs have almost halved between 1996 and 2002. which uses a unique type of Stirling engine with integral electricity generation within the sealed chamber (see p. One application of PVs is its potential radically to improve the quality of life in the rural regions of developing countries. for most purposes this has to be changed to alternating current (AC) by means of an inverter. Wind power Wind is a by-product of solar power and. In 2002 it was 56 per cent in Europe and 46 per cent in Japan. Whilst it is an intermittent source of power. at present. PV materials generate direct electrical current (DC) when exposed to light. wind power has been exploited as an energy source for over 2000 years. On a smaller scale. Silicon is. A variation of this principle is the SunDish Tower System of STM Power in the USA. only operates during daylight hours and is therefore subject to fluctuation in output due to diurnal. the dominant PV material which is deposited on a suitable substrate such as glass. This is certainly one area on which the industrialised countries should focus capital and technology transfer to less and least developed countries. and. Growth in the manufacture of PVs has been accelerating at an extraordinary pace. wind is a major resource. that is. Photovoltaics The amount of energy supplied to the Earth by the sun is five orders of magnitude larger than the energy needed to sustain modern civilisation. over 200 MW per year. Significant further cost reductions are confidently predicted coupled with steady improvements in efficiency.
At full revolutions the noise they create can be intrusive. Britain has the capacity to generate three times as much electricity by windpower as it consumes. The target is. Vertical axis machines such as the helical turbine are particularly appropriate for siting on buildings. as mentioned earlier. However. with the best wind regime in Europe. They have been implicated in interfering with television reception. the majority of which would be located in Scotland. The output is unpredictable. as sea levels rise and storm intensities increase. The UK government announced in 2003 that it is planning a 6000 MW expansion of offshore wind generation by 2010. The great majority of generators in operation are of the horizontal axis type with either two or three blades. There are two basic types of wind generator: horizontal and vertical axis. Of course the required rate of return is a contentious issue. On the other hand. They are said to interfere with radar signals and have raised concerns in the Ministry of Defence. there are drawbacks to this form of power. Whilst the technology is well developed and robust. Such sites are often some distance from the grid and centres of population. Expert opinion has it that. to say the least. ambitious but necessary if wind is to supply its overall share of 8 GW towards the declared 10 GW target for renewables by 2010. They are a particular hazard to birds and have attracted severe criticism from the Royal Society for the Protection of Birds (RSPB). The conventional method is to fix the machine to the sea bed. 46 . in practice there is a limit to the amount of unpredictable power the grid can accept and the realistic limit is said to be 32 TWh/y. It is estimated that it would be feasible to produce 55 TWh/y by wind generation. In addition to offshore sites. since it takes no account of the avoided cost to both the lower and upper atmosphere with all its global warming implications.ARCHITECTURE IN A CLIMATE OF CHANGE Europe but still has a considerable distance to go to meet its target of 8 per cent of total demand for wind generation by 2010. Several of the negative factors can be overcome by locating the generators offshore. The most frequently cited are: ● ● ● ● ● ● ● Often the most advantageous onshore sites are also places of particular natural beauty. Two major offshore wind farms have already been installed off the coast of North Wales near Rhyl and Scroby Sands off the Norfolk coast. some exposed estuaries will need hard barrages which could serve as tidal generators as well as affording ideal sites for wind turbines. At that time the existing installed capacity was 570 MW. they are relatively cheap and in the UK can generate electricity at a cost of 7 p/kWh assuming a 20-year life and a 15 per cent rate of return (Energy Paper 60).
SELCHP. It is estimated that the amount of fixed carbon in land plants is roughly equivalent to that which is contained in recoverable fossil fuels (The World Directory of Renewable Energy (2003). There is a growing market for domestic scale wind power and several firms are producing small-scale generators with an output ranging from 3. capable of generating 30 MW of electricity (DTI Renewable Energy Case Study: ‘Energy from Municipal Solid Waste’. Sheffield has one of the most extensive systems using Finnish technology and providing the city centre with heat and supplying power to the grid.RENEWABLE TECHNOLOGIES – THE WIDER SPECTRUM Harbour walls also have a highly favourable wind regime and therefore offer excellent sites. Sorted municipal solid waste (MSW) represents the greatest untapped energy resource for which conversion technology already exists. dioxins. These turbines will be considered in more detail in Chapter 9. However.5 to 22 kW which could be installed on buildings. An ever increasing body of regulations is limiting the scope to dispose of waste in traditional ways. James and James. as demonstrated by Blyth in Northumberland. In the UK there is a major plant in Lewisham in southeast London. Sweden and Austria generate a significant proportion of their electricity by burning the residue from timber processing. Whilst the economics of converting biomass and waste to energy are still somewhat uncompetitive compared with fossil fuels. There are three ways in which biomass and waste can be converted into energy: ● ● ● Direct combustion Conversion to biogas Conversion to liquid fuel. 47 . London). the presence of heavy metals in such waste poses a danger from toxic emissions including. The direct burning of municipal waste is becoming increasingly popular. Within the European Union the ‘set-aside’ land regulations have created an opportunity to put the land to use to create bio-fuels. Biomass and waste utilisation The term ‘biomass’ refers to the concept either of growing plants as a source of energy or using plant waste such as that obtained from managed woodlands or saw mills. Increasing environmental pressures are stimulating the growth of waste to energy schemes. it is claimed. 42. the pressure to reduce CO2 emissions combined with ‘polluter pays’ principles and landfill taxes for waste will change the economic balance in the medium term. p. Direct combustion Direct combustion represents the greatest use of biomass for fuel worldwide. Lewisham).
It also eliminates methane emissions from stored poultry litter.5 MW of power.8 million tonnes of poultry waste and 12 million tonnes of livestock slurry are produced annually. It has a capacity of 12. A much larger biomass plant is in operation in Thetford which consumes 450 000 tonnes per year of poultry litter to deliver 38. In the UK about 1. The authors identified nine compounds found in wood smoke that are known or suspected carcinogens. which involves a fermentation stage. a paper published in 1980 by Michael Allaby and James Lovelock drew attention to the risks to health associated with wood burning (‘Wood stoves: the trendy pollutant’. 48 . However. The engine would use ‘lean-burn’ technology to minimise emissions of nitrogen oxides and carbon monoxide (Power generation from landfill gas. wood and poultry droppings) was built at Eye. Its environmental benefit is that it reduces net CO2 emission by recycling carbon rather than producing new CO2. New Scientist. Anaerobic digestion uses wet waste products to produce energy in the form of methane-rich biogas.5 MW and uses about half the total of litter from broiler farms in the county.ARCHITECTURE IN A CLIMATE OF CHANGE The direct burning of rapid rotation crops is a technology which is said to be CO2 efficient since the carbon emissions balance the carbon fixed during growth. takes place in large heated tanks at either 30–35 C or 55 C during which 60 per cent of the organic material is converted to biogas. 13 November 1980). The liquids and solids which remain after digestion are used as fertilisers and soil conditioners. Gas is collected using a series of vertical collection wells connected to a blower which draws gas from the waste. It is claimed to reduce greenhouse gas emissions by 70 per cent compared with coal-fired plants. Biogas The most straightforward exploitation of biogas involves the tapping of methane produced by decaying waste material in landfill sites. Here co-operative ventures receiving waste from all the farms in a viable collection area are combined with non-toxic industrial and food waste to fuel extensive CHP networks. DTI Renewable Energy Case Study 2). This offers substantial biomass-to-energy conversion opportunities either as direct combustion or by using anaerobic digestion technologies. Cuxton. UK. The first UK commercial biomass electricity generating plant fuelled by poultry litter (a mixture of straw. Suffolk. The methane-rich gas is most effectively employed to fuel combined heat and power (CHP) schemes which is how the technology has been employed on an ambitious scale in Denmark. This has a considerable environmental benefit since it burns the methane which would otherwise add more intensively to the greenhouse problem. It also eliminates the production of the powerful greenhouse gas methane and nitrates which enter the water supply. The process. Foreign matter is extracted and the gas then fed to a conventional engine which drives a generator.
A mixture of ethanol. It has the potential to produce electricity for the grid using biowaste from agriculture and dedicated energy crops. The unit price of electricity generated by this process can be offset by the avoided costs of landfill disposal together with the taxes this incurs. improvements in the rate of growth per hectare combined with greater use in the generation of power for the grid together with steeply rising oil prices could save the situation. Liquid fuels The advantage of converting crops to liquid fuel is that it is portable and therefore suitable for vehicles. It produces fewer pollutants than petrol and is a net zero carbon fuel. Non-solid waste is superheated to produce methane which then fuels a steam turbine. ranging from 5 to 20 per cent. Alternatively. The first geothermal power station was built in Italy in 1913 and produced 250 kW. About half the gas emerging from the process is hydrogen. A problem for Brazil was that world energy prices had fallen to such an extent as to make ethanol uneconomic without government subsidy. its conversion efficiency is low. The mixture is heated and passed through two catalysts. This is known as the borehole heat exchanger 49 . However. The process involves heat recovery so that there is a commercial net energy gain in the process. The damage to health from low-level pollution is becoming increasingly a matter of concern and overtaking the greenhouse factor as the driving force behind the development of minimum polluting vehicles. There was a danger that the ethanol programme would collapse under the weight of market forces. Geothermal energy Natural hot water has been used since at least the nineteenth century for industrial purposes. Then it rises to between 50 and 70 per cent. Another use for ethanol is in the creation of hydrogen for fuel cells. Now 22 countries generate electricity using geothermal energy. thus alleviating two problems simultaneously.RENEWABLE TECHNOLOGIES – THE WIDER SPECTRUM The next logical step is to employ the technology to exploit the energy potential of human sewage on a national scale. One of the most promising technologies to have developed in recent years involves the gasification of municipal waste. Ethanol produced from sugar cane powers about 4 million cars in that country. hot dry rocks can supply energy by means of boreholes through which water is pumped and returned to the surface to provide space heating. water and air is fed to a reactor which is a compact fuel cell hydrogen generator. However. The world’s largest experiment in alternative fuel has been taking place in Brazil since 1975. Much greater efficiency is realised with the direct use of this energy for space or district heating.
Powerful elecromagnetic rings called tokamaks (like a doughnut) are able 50 . it is a major source of energy with one borehole for every 300 persons. a means must be found to regenerate the ground by artificial means. The Energy White Paper of 2002 deferred a decision on nuclear expansion until 2005 on the grounds that it would then review the potential of renewable technologies to fill the impending energy gap. Some consider that it would be folly to construct a new generation of tempting targets. There has been progress on the development of nuclear fusion – the power source that replicates the energy of the sun. The UK was one of the leaders in the field of hot dry rocks geothermal research. efforts to achieve a commercial return on this energy route have proved unsuccessful and further work has been abandoned. With buildings they can therefore be used for both heating and cooling. Nuclear power There are some who would place nuclear generation in the renewables category. The principle is that a mix of hydrogen isotopes is heated to 100 million degrees which causes their nuclei to fuse producing helium and massive amounts of energy. At the present rate of progress it would seem that this is a forlorn hope even though studies have shown that renewables can generate at least twice the capacity needed for the UK as stated earlier. Off-peak or PV electricity can be used to split water via an electrolyser to make hydrogen. Events of 2002 have illustrated how international terrorism has reached new heights of sophistication. in this context. This can be used as a direct fuel or to make electricity through the chemical reaction in a fuel cell (see p. and can be safely stored. This opens the way for the dual use of BHEs – heat collection in winter and heat rejection in summer. Those opposed to nuclear generation have been encouraged by the decision of the UK government to abandon plans to construct two further pressurised water plants. In Switzerland. The UK’s radioactive waste tally currently stands at 10 000 tonnes. nuclear power will remain an unsustainable energy source until its problems are solved in a way that will not impose a burden on future generations.ARCHITECTURE IN A CLIMATE OF CHANGE system (BHE). However. for example. Whilst there may be as yet no known limit to the availability of fuel for fission nuclear power stations. Hydrogen This is widely seen as the fuel of the future and will come in for further consideration in Chapter 13. the problems of security. It is non-polluting. has a reasonable calorific value. For these reasons. decommissioning and waste disposal remain largely unsolved. 90). If much more heat is required from the BHE in winter than can flow back in summer.
So far the problem has been that it has taken more energy to heat the gas to fusion temperature than is produced by the reaction. fusion reactors will not produce masses of highly radioactive waste staying a hazard for 250 000 years. 2000). p. Designs have been produced for the next generation of reactor by a consortium of the European Union. Japan and Russia – the International Tokamak Experimental Reactor (ITER). 20). if current trends continue. including the present rate of installing renewable technologies. it could be the world’s most important energy source over the next millennium’ (New Scientist. There has also been a problem of maintaining the high temperatures. UK Chief Government Scientist. the UK’s fusion laboratory at Culham has achieved breakeven between energy input and output. 51 . then by 2050 the country will need the equivalent of 46 of the latest Sizewell B type nuclear reactors to meet demand (Energy – The Changing Climate. However. It is predicted to produce ten times as much power as it consumes. According to Sir David King.RENEWABLE TECHNOLOGIES – THE WIDER SPECTRUM to store the superheated plasmas. A Japanese facility has achieved the same result. we could have commercial fusion electricity within 30 years. Unlike the present day nuclear fission reactor. Those concerned about a new generation of nuclear fission reactors should note the prediction in a Royal Commission report of 2000 that. ‘If successful. 10 April 2004. Royal Commission on Environmental Pollution Report.
The purpose was to ensure that a saturated external leaf would have no physical contact with the inner leaf apart from wall ties and that water would be discharged through weep holes at the damp-proof course level. In the UK housing has traditionally been of masonry and since the early 1920s this has largely been of cavity construction. Solid masonry walls with external insulation are common practice in continental Europe and are beginning to make an appearance in the UK. If you add the transport costs generated by buildings the UK government estimate is 75 per cent. upgrading buildings. for the industrialised countries. initially deemed necessary to conserve energy rather than the planet. it has been common practice to introduce insulation into the cavity. 52 . within that sector. accounting for over 50 per cent of total emissions. especially the lower end of the housing stock. Since the introduction of thermal regulations. For a long time it was mandatory to preserve a space within the cavity and a long rearguard battle was fought by the traditionalists to preserve this ‘sacred space’. Defeat was finally conceded when some extensive research by the Building Research Establishment found that there was no greater risk of damp penetration with filled cavities and in fact damp through condensation was reduced. Construction systems Having considered the challenge presented by global warming and the opportunities to generate fossil-free energy. housing is in pole position accounting for 28 per cent of all UK carbon dioxide (CO2) emissions. It is the built environment which is the sector that can most easily accommodate fairly rapid change without pain. it is now time to consider how the demand side of the energy equation can respond to that challenge. the best chance of rescue lies with the built environment because buildings in use or in the course of erection are the biggest single indirect source of carbon emissions generated by burning fossil fuels. creates a cluster of interlocking virtuous circles.Chapter Low energy techniques for Five housing It would appear that. The built environment is the greatest sectoral consumer of energy and. In fact.
From the energy point of view. Innovative techniques Permanent Insulation Formwork Systems (PIFS) are beginning to make an appearance in Britain. slate or tile hung external finish. there is an unfortunate history behind this system due to shortcomings in quality control. There can also be problems achieving internal fixings. maintenance demands rise considerably if it receives a rendered finish. framed buildings can accommodate high levels of insulation but have relatively poor thermal mass unless this is provided by floors and internal walls. the ultimate criticism is that it is illogical to have a framed building clad in masonry when it cries out for a panel. This can apply to timber which has not been adequately cured or seasoned. From the energy efficiency point of view. The advantages of masonry construction are: ● ● ● ● It is a tried and tested technology familiar to house building companies of all sizes. It is durable and generally risk free as regards catastrophic failure – though not entirely.LOW ENERGY TECHNIQUES FOR HOUSING In Cornwall the Penwith Housing Association has built apartments of this construction on the sea front. Framed construction Volume house builders are increasingly resorting to timber-framed construction with a brick outer skin. Exposed brickwork is a low maintenance system. making them appear identical to full masonry construction. Pressed steel frames for homes are now being vigorously promoted by the steel industry. usually expanded polystyrene. boarded. Framed buildings need to have a vapour barrier to walls as well as roofs. masonry homes have a relatively high thermal mass which is considerably improved if there are high density masonry internal walls and concrete floors. However. perhaps the most challenging of situations. The selling point is again speed of erection but with the added benefit of a guaranteed quality in terms of strength and durability of the material. The principle behind PIFS is the use of precision moulded interlocking hollow blocks made from an insulation material. They can be rapidly assembled on site and then filled with pump grade concrete. A few years ago the entire outer leaf of a university building in Plymouth collapsed due to the fact that the wall ties had corroded. For the purist. With timber framing it is difficult to avoid piercing the barrier. When the concrete has set the result is a highly insulated wall ready for the installation of 53 . The attraction is the speed of erection especially when elements are fabricated off site.
existing obstructions on the site. Ease and speed of erection. almost any plan shape is possible. Most often used is the stereographic sun chart (Figure 5. site orientation and slope. Computer modelling of shadows cast by the sun from any position is offered by Integrated Environmental Solutions (IES) with its ‘Suncast’ 54 . They can achieve a U-value as low as 0. The advantages of this system are: ● ● ● Design flexibility. Sunlight and shade patterns cast by the proposed building itself should also be considered. skill requirements are modest which is why it has proved popular with the self-build sector. Graphical and computer prediction techniques may be employed as well as techniques such as the testing of physical models with a heliodon. The finished product has high structural strength together with considerable thermal mass and high insulation value. Experienced erectors can achieve 5 m2 per man hour for erection and placement of concrete. In this case buildings are designed to take full advantage of solar gain without any intermediate operations.11 W/m2K. to be plotted. potential for overshadowing from obstructions outside the site boundary. On the same chart a series of sun path trajectories are also drawn (usually one arc for the 21st day of each month).1) in which a series of radiating lines and concentric circles allow the position of nearby obstructions to insolation. Solar design Passive solar design Since the sun drives every aspect of the climate it is logical to describe the techniques adopted in buildings to take advantage of this fact as ‘solar design’. One of the methods by which solar access can be evaluated is the use of some form of sun chart.ARCHITECTURE IN A CLIMATE OF CHANGE services and internal and exterior finishes. The intersection of the obstructions’ outlines and the solar trajectories indicate times of transition between sunlight and shade. Above three storeys the addition of steel reinforcement is necessary. Normally a different chart is constructed for use at different latitudes (at about two degree intervals). such as other buildings. Access to solar radiation is determined by a number of conditions: ● ● ● ● the sun’s position relative to the principal facades of the building (solar altitude and azimuth). also marked are the times of the day. The most basic response is referred to as ‘passive solar design’.
they perform the dual function of permitting solar penetration during the winter whilst providing a degree of shading in the summer. rows of houses on a 10 north-facing slope must be more than twice as far apart than on 10 south-facing slope. Passive solar design can be divided into three broad categories: ● ● ● direct gain. However.com). However. indirect gain. The spacing between buildings is important if overshading is to be avoided during winter months when the benefit of solar heat gain reaches its peak.ies4d. if they are deciduous. the incident solar radiation is transmitted by facade glazing to the interior where it is absorbed by the internal surfaces causing warming. Again spacing between trees and buildings is critical. Trees can obviously obstruct sunlight. attached sunspace or conservatory.LOW ENERGY TECHNIQUES FOR HOUSING Figure 5. re-emission of heat back through 55 . In buildings.1 Stereographic sun chart for 21 March program. if overshading is to be avoided at a latitude of 50 N. Each of the three categories relies in a different way on the ‘greenhouse effect’ as a means of absorbing and retaining heat. For example. The greenhouse effect in buildings is that process which is mimicked by global environmental warming. On sloping sites there is a critical relationship between the angle of slope and the level of overshading. This is a user-friendly program which should be well within normal undergraduate competence (www.
To reduce the potential of overheating in the summer. within about 30 of south for the northern hemisphere. As far as the glazing is concerned. Solar radiation is admitted directly into the space concerned. with suspended timber floors a carpet is an advantage in excluding draughts from a ventilated underfloor zone. which reduces temperature fluctuations inside the building.3). During the day and into the evening the warmed floor should slowly release its heat. Thickness greater than this provides marginal improvements in performance but can be useful in some longer-term storage options. for the normal daily cycle of heat absorption and emission.ARCHITECTURE IN A CLIMATE OF CHANGE the glazing is blocked by the fact that the radiation is of a much longer wavelength than the incoming radiation.2) and the Hockerton Project of 1998 by Robert and Brenda Vale (Figure 5. However. This is because the re-emission is from surfaces at a much lower temperature and the glazing reflects back such radiation to the interior. shading may be provided by designing deep eaves or external louvres. it is only about the first 100 mm of thickness which is involved in the storage process. A vapour barrier should always be on the warm side of any insulation. The main occupied living spaces should be located on the solar side of the building. Internal 56 . In the case of solid floors. designed in 1967 (Figure 5. Thick carpets should be avoided over the main sunlit and heatabsorbing portion of the floor if it serves as a thermal store. Two examples 30 years apart are the author’s house in Sheffield. and the time period over which it happens makes it a very suitable match to domestic circumstances when the main demand for heat is in the early evening. As regards the benefits of thermal mass. insulation should be beneath the slab. Direct gain Direct gain is the design technique in which one attempts to concentrate the majority of the building’s glazing on the sun-facing facade. The main design characteristics are: ● ● ● ● ● ● ● ● ● Apertures through which sunlight is admitted should be on the solar side of the building. Windows facing west may pose a summer overheating risk. the following features are recommended: ● ● Use of external shutters and/or internal insulating panels might be considered to reduce night-time heat loss. Windows should be at least double glazed with low emissivity glass (Low E) as now required by the UK Building Regulations. The floor should be of a high thermal mass to absorb the heat and provide thermal inertia.
3 Passive solar houses. Hockerton Self-Sufficient Housing Project 1998 57 . ● ● Figure 5. Sheffield 1960s Figure 5.LOW ENERGY TECHNIQUES FOR HOUSING blinds are the most common technique but have the disadvantage of absorbing radiant heat thus adding to the internal temperature. Light shelves can help reduce summer overheating whilst improving daylight distribution (see Chapter 14).2 Passive solar house. Heat reflecting or absorbing glass may be used to limit overheating. The downside is that it also reduces heat gain at times of the year when it is beneficial.
ARCHITECTURE IN A CLIMATE OF CHANGE Figure 5. Indirect gain In this form of design a heat absorbing element is inserted between the incident solar radiation and the space to be heated. thus the heat is transferred in an indirect way.4 Hockerton individual house unit solar space Direct gain is also possible through the glazing located between the building interior and attached sunspace or conservatory. In each of these cases some consideration is required concerning the nature and position of the absorbing surfaces. and this thermal storage wall controls the flow of heat into the building. The main elements 58 . In the UK climate and latitude as a general rule of thumb room depth should not be more than two and a half times the window head height and the glazing area should be between about 25 and 35 per cent of the floor area. This often consists of a wall placed behind glazing facing towards the sun. it also takes place through upper level windows of clerestory designs.
Flap to control reverse flow at night Thermal storage wall Opening to permit air flow Figure 5.LOW ENERGY TECHNIQUES FOR HOUSING contributing to the functioning of the design are: ● ● ● ● ● High thermal mass element positioned between sun and internal spaces.6).5 Indirect solar – Trombe wall In countries which receive inconsistent levels of solar radiation throughout the day because of climatic factors (such as in the UK). In order to derive more immediate heat benefit. Typical thicknesses of the thermal wall are 20–30 cm.5 and 5. air can be circulated from the building through the air gap between wall and glazing and back into the room. The area of the thermal storage wall element should be about 15–20 per cent of the floor area of the space into which it emits heat. Note the hydrogen storage tank on the right 59 . In homes the flow can be delayed so that it arrives in the evening matched to occupancy periods. In this modified form this element is usually referred to as a Trombe wall. At times of excess heat gain the system can provide alternative benefits with the air circulation vented directly to the exterior carrying Figure 5. the heat absorbed slowly conducts across the wall and is liberated to the interior some time later. Heat reflecting blinds should be inserted between the glazing and the thermal wall to limit heat build-up in summer (Figures 5.6 Freiburg Solar House showing Trombe walls with blinds in operation. the option to circulate air is likely to be of greater benefit than awaiting its arrival after passage through the thermal storage wall. Glazing on the outer side of the thermal wall is used to provide some insulation against heat loss and help retain the solar gain by making use of the greenhouse effect. Materials and thickness of the wall are chosen to modify the heat flow.
As a result. a preheater for ventilation air or simply an adjunct greenhouse for plants (Figure 5.ARCHITECTURE IN A CLIMATE OF CHANGE away its heat. and partly as a result of the implied dark surface finishes of the absorbing surfaces. On balance it is considered that conservatories are a net contributor to global warming since they are often heated.7). partly because of the restrictions on position and view out from remaining windows. and those of a more ‘active’ nature. discussed earlier. Blinds/ insulation Air movement between sunspace and building Indirect gain Direct gain Figure 5. Ideally the summer heat gain should be used to charge a seasonal thermal storage element to provide background warmth in winter. Indirect gain options are often viewed as being the least aesthetically pleasing of the passive solar options. a solar heat store. At the very least. It can function as an extension of living space.4). The most adventurous sunspace so far encountered is in the Hockerton housing development which will feature later (Chapter 8 and see Figure 5. this category of the three prime solar design technologies is not as widely used as its efficiency and effectiveness would suggest. air flow paths between the conservatory and the main building should be carefully controlled. Attached sunspace/conservatory This has become a popular feature in both new housing and as an addition to existing homes. at the same time drawing in outside air to the building from cooler external spaces. The area of glazing in the sunspace should be 20–30 per cent of the area of the room to which it is attached.7 Attached sunspace 60 . Active solar thermal systems A distinction must be drawn between passive means of utilising the thermal heat of the sun. Ideally the sunspace should be capable of being isolated from the main building to reduce heat loss in winter and excessive gain in summer.
For solar energy to realise its full potential it needs to be installed on a district basis and coupled with seasonal storage. a penalty is incurred since energy is required to control and operate the system known as the ‘parasitic energy requirement’. A further distinction is the difference between systems using the thermal heat of the sun. Solar collectors preheat water using a closed circuit calorifier. They convert direct solar radiation into another form of energy. One of the largest projects is at Friedrichshafen (Figure 5.8 Diagram of CSHPSS system.. Friedrichshafen (courtesy of Renewable Energy World (REW)) 61 . Germany Figure 5. and systems. which convert solar energy directly into electrical power. The emergence of Legionella has highlighted the need to store hot water at a temperature above 60 C which means that for most of the year in temperate climes active solar heating must be supplemented by some form of heating.8). such as photovoltaic cells. Active systems are able to deliver high quality energy.LOW ENERGY TECHNIQUES FOR HOUSING Active systems take solar gain a step further than passive solar. However.
To exploit their efficiency to 62 . Types of solar thermal collector The flat plate collector These units are. In the UK they are usually limited to providing domestic hot water.9 Seasonal storage tank under construction. Behind the plate are pipes which carry the heat extraction medium. There are two types of heat absorbing medium. active solar has considerable potential not just for heating water but also for electricity generation. The scale of this storage facility is indicated by Figure 5. It is then distributed to the apartments as required. Friedrichshafen (courtesy of REW) of solar collectors on the roofs of eight housing blocks containing 570 apartments is transported to a central heating unit or substation. being principally domestic hot water. The heated living area amounts to 39 500 m2. Surplus summer heat is directed to the seasonal heat store which. solar energy accounts for almost total demand.ARCHITECTURE IN A CLIMATE OF CHANGE Figure 5.9. Water containing an anti-freeze solution is the most common and is circulated behind an absorber plate to extract and transfer its heat. is of the hot water variety capable of storing 12 000 m3. The heat delivery of the system amounts to 1915 MWh/year and the solar fraction is 47 per cent. flat plates tilted to receive maximum solar radiation. In places with high average temperatures and generous sunlight. The month by month ratio between solar and fossil-based energy indicates that from April to November inclusive. in this case. mainly in the summer months. as the name indicates. air and water. This has particular relevance to less and least developed countries.
12). insulation behind the plate and pipes (Figures 5.11). Evacuated tube collectors The most recent form of collector is the evacuated tube or vacuum tube system.10 Flat plate collector Insulator Flow passages A more sophisticated version was devised for the Freiburg Solar House. The reflected radiation means that the collector receives heat on both sides. nearly doubling its efficiency. These units heat water from 60 to 80 C which is 1.LOW ENERGY TECHNIQUES FOR HOUSING the full there should be a heat storage facility which accepts excess heat during the summer to top up heating needs the rest of the year. Transparent insulation 4. a pipe circuit to absorb and transport the heat. the size of both the collectors and storage tanks makes this an uneconomic proposition in most cases. The collector is placed within a semi-circular reflector. Freiburg Solar House 63 . Low iron containing glass 5. It works by exploiting a vacuum around the collector which reduces heat loss from the system. There are four main components to the design: ● ● ● ● Transparent cover plate Absorber plate transparent cover plate. Reflector Figure 5. Coupled with insulated water storage this system was able to supply all the domestic hot water for the whole year (Figure 5. Air gap 3. making it especially suitable for more temperate climes. Figure 5.10 and 5.11 Double-sided solar collector. However. Absorber 2. heat absorber plate.
Architect) sufficient for providing domestic hot water. Also there have been considerable advances in the thermal efficiency of glazing. yet these are merely a foretaste of things to come. However. aside from the obvious.F. (For more information see Smith. 2.0 W/m2K. Osney Island. Radiant effects are further increased if the 64 .2 illustrates the impact of solar gain according to orientation by giving the net U-values. Windows have many benefits.ARCHITECTURE IN A CLIMATE OF CHANGE Figure 5. they are the main weak thermal link when incorrectly specified. They can continue to operate under cloudy conditions and should be linked to an insulated storage facility for continuity of supply. Discomfort arises in summer. Table 5. especially in the sphere of glass. but also due to the rise in radiant temperature from the glass surface itself.) Windows and glazing In recent years there has been rapid development in the technology of the building envelope. with U-values now commercially better than 1. the installation cost is significantly higher than for flat bed collectors. (2002) Sustainability at the Cutting Edge. Architectural Press.12 Flat bed solar thermal collectors. Glazing systems are now possible which react to environmental conditions such as light and heat. Table 5. Ch. Nevertheless. P. not just from the rise in air temperature due to heat gains.1 shows the heat transfer characteristics of seven glazing systems. Oxford (courtesy of David Hammond.
Visible light and solar heat gain are both parts of the electromagnetic spectrum of energy emitted by the sun. which increases absorption.7 0. there may well be an asymmetric temperature field leading to greater discomfort.6 2.3–0.0–0.LOW ENERGY TECHNIQUES FOR HOUSING Glazing Single glazing Double glazing Triple glazing Double with Low E Double with Low E and Argon Triple with 2 Low E and 2 Argon Double with Aerogel U-value (W/m2K) 5.1 Comparison of typical heat transfer through different glazing options Glazing South Single glazing Double glazing Triple glazing Double with Low E Triple with Low E 2.4–2. The following are some examples. the absorbed component. absorbed and transmitted radiation could be engineered by changing the glazing system properties.0 Table 5.8 0. As pressure has increased to improve the thermal efficiency of buildings this has forced the pace of developments in glass technology.6 Table 5.2–2.5–1.1–2.4 2.2 0.8–1.6 3. Modifications in the proportions of reflected.1–0.2–3.0 1.2 Effective net U-value taking account of solar heat gain occupant experiences unshaded sunlight. cold window surfaces cool the adjacent internal air.6 1.6–5.2 1.6–1.4 2.5–0.9 North 4. The interaction of glazing with light and solar heat has three components: reflection. In winter. usually.1 0. This would also be accompanied by a cool radiant temperature. which increase the reflected component and. Along with the change in temperature. using combinations of body tinted and reflective coatings.0 2. Heat reflecting and heat absorbing glazing These products are usually considered for application in situations where overheating poses a risk. using reflective coatings.0 0.6 0. 65 .4 0.9–1.4 1.3 U-value ( W/m2K) with solar gain East/west 3.4 0.7–4.2 0.7–1. which then falls under the buoyancy effect leading to a cold downdraught. There are several ways of achieving this: ● ● ● using ‘body tinted’ glass. absorption and transmission.8–3.
though some tinting and reflective products are more selective than others. glazing is specified to reduce heat gain. reflective coated glass has a better performance. the heat absorbed must be dissipated as the glass temperature increases. The reflected component can be increased by changing the angle of incidence – the more acute the angle. which can be as low as 10 per cent in some cases. To achieve this second aim. Though body tinted glass has an effect on heat transmission it also has aesthetic implications. Photochromic. In hot climates. plus the fact that higher levels of natural daylight are required. The warmth of the glass transmits heat inwards as well as outwards. In temperate climates a balance must be struck between control of summer heat gain and the benefits of winter sun. reducing the directly transmitted component. There are considerable technical problems to scaling up photochromic glass to normal window size.. 66 . both by direct solar transmission. the greater the reflection. or by applying a second laminating layer. bronze and blue. It is easier to specify and produce a glass with specific properties for a specific application than with body tinted varieties. Avoidance of glare and the provision of some natural light and view. and by conduction. The tinting is produced by the addition of small amounts of metal oxides during production. and it is present throughout the thickness of the glass. No two situations are quite the same and it is important to consider the full range of options before choosing a particular product or glazing system. Because of this the body tinted layer would normally be installed as the outer pane of a multipane unit. thermochromic and electrochromic glass Each of these terms describes a variety of glazing in which the transmission properties are variable. green. a double glazed unit with a reflective outer layer is combined with a low emissivity coated inner layer to reflect outwards the heat which is transmitted. However. The effect is to increase the absorption of the radiation within the glazing. For improved solar heat gain attenuation. Body tinted glass is normally available in a range of colours including grey. Reflective coatings are available in a wide range of colours and with a wide range of performance specifications. are also considerations. These react automatically to light levels. Extensive opportunities exist for the development of some of these technologies to allow dynamic control of light and heat gain to match building and occupant requirements. Photochromic devices change transmission in response to prevailing radiation levels. Small examples have been in everyday use for some years in the form of sunglasses and spectacles.
It will be available in a range of sizes up to 3. As it reacts to heat it may not be so suitable for windows since it could react to the internal temperature and again cannot be independently controlled. Their construction consists of complex multi-layered transparent coatings. The latest version from Pilkington is EControl glass which can. in other words. especially for commercial buildings. Rainwater forms an overall film on the glass rather than collecting in drops that deposit dirt which remains after drying. Capital cost savings in terms of reduced cooling requirements and the exclusion of blinds plus revenue savings in respect of lower energy costs make electrochromic glass an attractive option. This should offer significant revenue cost savings in maintenance. It has a laminated structure incorporating a chemical which turns opaque at around 30 C. It will be marketed as PowerGlaz and should be available towards the end of 2004. especially since it can be controlled by the occupants – a major factor in workplace satisfaction. Pilkington is also developing a solid state electrochromic glass.LOW ENERGY TECHNIQUES FOR HOUSING Thermochromic glass has changing optical properties in response to temperature variations.3 2. Romag. has joined with BP Solar to produce a composite glass which incorporates PV cells. cut out over 80 per cent of solar radiation.2 metres. The electrical signal reduces the transmission capacity of the electrochromic layer between two sheets of glass affecting not only daylight but also solar heat. 67 . at the flick of a switch. the properties of which can be changed by the application of a small electrical current. a company specialising in laminated glass. without any applied coatings. reducing insolation by about 70 per cent. It can also achieve an airborne sound insulation level of 42 dB using thicker internal glass and a special sound insulating gas between the panes. The most refined and controllable of the three options is electrochromic glass. Pilkington has recently marketed a self-cleaning or ‘hydrophilic’ glass known commercially as ‘Pilkington Activ’. For this reason an ideal application is as external solar shading.
many insulation products are based upon materials that have numerous layers or pockets of air trapped within them. Thermal insulation. Since air provides good resistance to heat flow. is used to reduce the magnitude of heat flow in a ‘resistive’ manner. When specifying insulation materials it is important avoid those which are harmful to the environment such as materials involving chlorofluorocarbons (CFCs) in the production process and to select materials with zero ozone depletion potential (ZODP). chimneys. the greater the heat flow. In several domestic and other small buildings. not capable of giving structural strength. 68 . glass fibre and ‘Rockwool’. Walls. they are unable to provide the same level of resistive insulation. roofs. The main heat transfer process for solid. Generally. floors. windows are all escape routes.g. opaque building elements is by conduction. Since structural components are often. Heat flow through building components can be modified by the choice of materials.Chapter Insulation Six Warmth is a valuable commodity and it will seek every possible means of escape from walls. Most UK buildings make escape easy. the higher the density. Warmth is a valuable commodity and it will seek every possible means to escape from a building. of necessity. roofs. rather high in density. It may be necessary to provide additional layers of insulation around them to prevent such elements acting as weak links or ‘cold bridges’ in the thermal design. Increased levels of insulation are a cost-effective way of reducing heating energy consumption. which provides a restriction to heat flow. Such materials are thus low density and lightweight. e. in most cases. and. it has already been demonstrated that the additional costs of insulation can be offset against a much reduced cost for the heating system involving a whole building radiator and central boiler option. windows and floors. Insulation materials fall into three main categories: ● Inorganic/mineral – these include products based on silicon and calcium (glass and rock) and are usually evident in fibre boards.
The range of insulation options There are numerous alternatives when it comes to choosing insulation materials. Moisture can build up in the insulant reducing its insulating value. Inorganic/mineral-based insulants Inorganic/mineral-based insulants come in two forms. (ed. Health and safety There is a health issue with fibrous materials. The thermal conductivity of a material ‘is the amount of heat transfer per unit of thickness for a given temperature difference’ (Thomas. Glass wool As for rock wool. Lambda value 0.) (1996) Environmental Design.) (1996) Environmental Design. R. Technically it is a measure of the rate of heat conduction through 1 cubic metre of a material with a 1ºC temperature difference across the two opposite faces. fibre or cellular structure. E & FN Spon). Loose fill 69 . May degrade over time. Some also lose much their insulating efficiency if affected by moisture. For fibrous materials such as glass and mineral fibres there is a theoretical risk of cancer and non-malignant diseases like bronchitis. at the outset it is advisable to understand something about the most readily available insulants.INSULATION ● ● Synthetic organic – materials derived from organic feedstocks based on polymers. (ed. Natural organic – vegetation-based materials like hemp and lamb’s wool which must be treated to avoid rot or vermin infestation. E & FN Spon.040 W/mK. 10). The lower the value the more efficient the material. This is a matter that is still under review (Thomas. The thermal efficiency of an insulant is denoted by its thermal conductivity. They differ in thermal efficiency and in offering certain important properties like resistance to fire and avoidance of ozone depleting chemicals. p. termed lambda value.033–0. So. Fibre Rock wool Rock wool is produced by melting a base substance at high temperature and spinning it into fibres with a binder added to provide rigidity. R. It is vapour and air permeable due to its structure. Some cause skin irritation and it is advisable to wear protective gear during installation. measured in W/mK.
027–0. they are currently listed as ‘not classifiable as to carcinogenicity in humans’. It has a high insulation value.018–0. Vermiculite Vermiculite is the name given to a group of geological materials that resemble mica. Cellular Cellular glass Manufactured from natural materials and over 40 per cent recycled glass. PIR (polyisocyanurate) Cellular plastic foam. vapour tight. and non-irritant. flame retardant cellular. Lambda value 0. Lambda value 0. Lambda value 0. Organic/synthetic insulants Organic/synthetic insulants are confined to cellular structure: EPS (expanded polystyrene) Rigid. dimensionally stable. non-combustible. Lambda value 0. vermin-proof and has high compressive strength as well as being CFC and HCFC free.019 W/mK. cellular materials do not pose a health risk and there are no special installation requirements.037–0. XPS (extruded polystyrene) Closed cell insulant water and vapour tight.032–0. available CFC and HCFC free. Lambda value 0. is resistant to decay. However. available CFC and HCFC free. Typical proprietary brand: Foamglas by Pittsburgh Corning (UK) Ltd. In general. It is impervious to water vapour and is waterproof. 70 . vapour resistant plastic insulation.025–0. Phenolic Rigid cellular foam very low lambda value. CFC and HCFC free.047 depending on particular application. There has been the suggestion that fibrous materials constitute a cancer risk. vapour tight. non-toxic. good fire resistance.ARCHITECTURE IN A CLIMATE OF CHANGE fibre insulants should not be ventilated to internal habitable spaces. free from CFCs and HCFCs. odourless.028 W/mK. When subject to high temperature the flakes of vermiculite expand due to their water content to many times their original size to become ‘exfoliated vermiculite’.040 W/mK.036 W/mK.
Main points Insulation materials should be free from HFCs and HCFCs: ● ● The choice of insulation material is governed primarily by two factors: thermal conductivity and location in the home. energy involved in the extraction and manufacturing process.INSULATION Natural/organic insulants Fibre structure Cellulose Mainly manufactured from recycled newspapers. is also a factor to consider. grows without needing pesticides and produces no toxins. Disposal may have to be at specified sites. However. It can be used as a wall material with a high thermal efficiency. Straw Heat treated and compressed into fibre boards. Hemp Under development as a compressed insulation board. In its present day form it should be much more reliable than the strawboard of the 1960s which had a tendency to germinate. Manufactured into fibres. 71 . Lambda value 0. there are certain overriding factors which will be described below. Insulation materials derived from mineral fibres tend to be among the lowest in embodied energy and also CO2 emissions. Embodied energy.037 W/mK. Initial tests have used hemp as a building material mixed with lime and placed like concrete.040 W/mK.040 W/mK. Lambda value 0. Lambda value 0. Flax Treated with polyester and boron. for example 200 times for expanded polystyrene and 1000 times for glass fibre. that is.037 W/mK. A highly eco-friendly material. Treated with fire retardant and pesticides. Treated with fire retardant and pesticide.038–0. The ecological preference is for materials derived from organic or recycled sources and which do not use high levels of energy during production. overall the use of insulation saves many times the embodied energy of even the worst cases. Test houses have proved as thermally efficient as identical well-insulated brick built houses built alongside the hemp examples. However. Lambda value 0. batts or boards. Sheep’s wool Must be treated with a boron and a fire retardant.
020 0.ARCHITECTURE IN A CLIMATE OF CHANGE Table 6.1 W/m2K. Insulation thickness is often constrained by accepted construction techniques. A broader definition of superinsulation is one which specifies a maximum overall building heat loss which permits ‘trade-offs’ within certain limits.035 0. Rockwool products are among the most stable in this respect. The use of superinsulation has so far been best demonstrated at the domestic scale. This may be partly due to the problems of overheating experienced in many larger. for example by an allowance for solar gain.025 0.1 Summary of comparative performance of insulation materials Expanded polystyrene slab Extruded polystyrene Glass fibre quilt Glass fibre slab Mineral fibre slab Phenolic foam Polyurethane board Cellulose fibre Thermal conductivity (W/mK) 0. High and superinsulation In recent years attention has been focused towards the use of very thick layers of insulation within the building fabric in order to minimise heat flow. problems which override the benefits of reduced winter heating requirements.040 0. Extruded polystyrene foams are attractive to house builders because they have good water resistance and a stiffness that enables them to be used in cavities.030 0. This technique has become known as superinsulation.035 0. 72 .1 shows the thermal conductivity of the main insulants.2 W/m2K for all major non-transparent elements and often below 0. rather than individual component values. there is the factor of internal strength or friability.035 0. buildings which exhibit less tendency to overheat due to better environmental design may modify the priorities and make superinsulation attractive in all circumstances where buildings experience cold seasons. deeper plan commercial buildings. for instance by allowable cavity widths in cavity wall construction. Finally. In the future. however.035 Table 6. Superinsulation is associated with several design features: ● ● ● To qualify as superinsulated the building fabric should have U-values that are less than 0.
the typical thickness of insulation material is likely to be of the order of 150 mm in walls and 300 mm in roofs (Figure 6.1).2).INSULATION ● ● In the case of low-energy housing. superinsulated walls may have 200–300 mm with 400 mm in the roof (Figure 6. The Jaywick Sands development is a social housing project which is designed on sustainability principles..1 Section. With cavities of 200–300 mm width it is essential to have rigid wall ties of either stainless steel or tough rigid plastic. Its ‘breathing’ walls consist of Figure 6. typical low energy construction 73 .
They are filled with 170 mm Warmcell insulation and clad with 9 mm sheathing board faced with a breather membrane.3).ARCHITECTURE IN A CLIMATE OF CHANGE Figure 6. Southwell (courtesy of Robert and Brenda Vale) partially prefabricated storey height structural panels (Figure 6. The exterior finish is western red cedar boards on battens. It can be argued that the insulation would have been better on the underside of the concrete to allow the slab to provide a degree of thermal mass (the scheme is described in detail in The Architects Journal. 23 November 2000).2 Superinsulation in the Autonomous House. The floor is a pot and beam precast concrete slab with 60 mm rigid insulation on the upper surface. 74 .
Jaywick Sands.3 Low energy timber panel housing. Essex 75 .INSULATION Figure 6.
The walls have a U-value of 0.4).4 Section of the Wadenswil House 76 . Polycarbonate honeycomb collectors absorb solar radiation to heat domestic water to 25 C even on cloudy days.2 W/m2K.85 W/m2K. The annual energy consumption is around 14 kWh/m2 excluding solar energy (Figure 6. Switzerland. This is supplemented by a heat storage facility and backup liquid petroleum gas (LPG) heater unit.13 W/m2K. Pressure tested to 50 pascals (Pa) the rate of air change was 0. Space heating is also supplied by solar collectors and delivered in pipes embedded in the concrete floors.15 W/m2K. Timber framed windows are triple glazed with Low-E coatings and an argon gas filled cavity achieving a U-value of 1. The roof has 180 mm of mineral fibre insulation giving it a U-value of 0. The structural wall consists of 150 mm dense concrete blocks. Air tightness is a prime consideration at this level of energy efficiency. 3 mm bitumous plastic Figure 6.ARCHITECTURE IN A CLIMATE OF CHANGE On mainland Europe solid wall construction is much more common than in the UK. These are faced with 180 mm of extruded polystyrene insulation protected by external cladding.4 per hour. North facing windows are quadruple glazed achieving a U-value of 0. An example is the Zero-energy House at Wadenswil.
For example. a cubic metre of silica glass would weigh about 2000 kilograms. It would be possible to achieve a 99 per cent vacuum between the panes since they are supported by a solid.6). metals even rubber. Despite this aerogels are relatively strong. They are extremely light. However. A silica aerogel block of the same dimensions would weigh 20 kilograms. retaining absorbed heat very effectively. Flat plate solar panels collect heat then radiate it back into space. The Freiburg Solar House shows Trombe walls with some blinds lowered (Figure 5. except the gap between glazed outer skin and the surface of the wall which faces into it contains insulation which is transparent rather than just air. having about one hundredth the thermal conductivity of glass.5). The technology has similarities to the passive solar thermal mass wall designs already described. Aerogels are excellent insulators. The thermal properties of aerogels also make them ideal for harvesting solar heat. Aerogels are a form of translucent insulation material which is located within a glazing sandwich.INSULATION Transparent insulation materials Transparent insulation materials (usually abbreviated to TIMs) are a class of product which make use of particular materials to enhance the solar heat gain whilst simultaneously reducing the heat loss by conduction and radiation. Double glazing which replaced the gap with an aerogel would improve the insulation value by a factor of three as against the very best current multiple glazing. A blind behind a glazed rain screen would minimise an excessive build-up of heat in summer (Figure 6. They are sometimes called ‘frozen smoke’ due to their translucent appearance. An aerogel glass sandwich would provide a one-way barrier to the re-radiation of heat from the absorbing surface. Faced with a glass aerogel screen the heat would be retained and radiated into the interior of the building. In the case of the silica aerogel it consists of tiny dense silica particles about 1 nanometre across which link up to form a gel. The insulation allows transmission of the incoming solar radiation but acts as a barrier to conductive and radiative heat loss. Some problems relate to the presence of moisture within the building 77 . This would have an obvious application in active solar panels and also in solar walls. even with a thin aerogel sandwich the window would have a slightly frosted appearance. The outer surface of the wall would be coated black to maximise absorption. Insulation – the technical risks The use of high levels of insulation brings with it some risks. Aerogels Aerogels are materials that are mostly air – usually around 99 per cent by volume – and can be fabricated from silica.
for example: ● ● ● ● ● at the junction of roof and wall. and when wet. Particular attention must therefore be paid to ensuring adequate and correctly designed insulation details at floor edges. 78 . Some insulation materials absorb moisture. water. or wall and floor. particularly frames and lintels. The problem mainly occurs at the junction between main structural components. at positions where structural framing elements connect with roofs. The answer is to ensure continuity of insulation. drainage. their insulating effect is very much reduced. this creates weak links. This can lead to several difficulties such as rotting.5 Transparent/translucent insulation wall construction which. When considering floors. condenses into water. because the temperature gradient has been changed by the presence of insulation. If substantial variations exist between the insulation levels of different parts of the building fabric. It is on the inner surfaces of such cold bridges that condensation will occur. etc. Cavity insulation should be treated with a water repellent. walls and floors. the majority of the heat loss occurs at its exposed edges.ARCHITECTURE IN A CLIMATE OF CHANGE Figure 6.. which then become the main cold bridges or ‘thermal bridges’. around windows and doors. around apertures for building services – electrical. rusting or other degradation of components. and in addition can pose a safety risk if it comes into contact with electrical circuitry.
79 . It is advisable to carry out a technical assessment of the condensation risk if this is suspected of being a problem. As stated earlier. as a general principle.INSULATION The use of vapour barriers becomes more important as insulation levels rise. vapour barriers should always be on the warm side of the insulation. A large proportion of the reported faults associated with condensation are attributable to poor workmanship. It is even more important to design components correctly and ensure that the construction is carried out according to the specification. otherwise they will actually cause condensation. since it is the appropriate construction and positioning of such layers that reduces condensation risk.
or linked to. By far the most convenient form of renewable energy system which can be linked to housing is photovoltaic cells. create no noise in operation. Southwell.Chapter Domestic energy Seven Electricity produced by a stand-alone system within.1). Figure 7. One of the pioneer examples of a domestic application in the UK is the Autonomous House by Robert and Brenda Vale in Southwell. and seem attractive from both aesthetic and scientific perspectives. also with an indication of the sunspace 80 . Nottinghamshire (Figure 7. Autonomous House. As unit costs fall PV arrays attached to individual houses will become increasingly evident. a building is called ‘embedded’ energy generation. Photovoltaic systems As stated earlier PV cells have no moving parts. In several countries there are substantial state subsidies to kick-start the PV industry so that costs can quickly fall due to the economy of scale.1 Remote PV array.
Examples of PV integrated cladding include the adaptation of rain screens. roof tiles and windows. each layer having different electrical characteristics. no additional land requirements. At present most PVs consist of two thin layers of a semi-conducting material. The greatest potential growth area is with building integrated PVs within facade and roof components. equivalent to bright sun. 81 . These two neighbouring regions generate an electrical field. though significant output is still possible with overcast skies. This law has recently been re-enacted and a further 100 000 PV roofs target has been instigated. The output is direct current (DC) which must be changed to alternating current (AC) by means of an inverter if it is to be fed to the grid. The principle of photovoltaic cells (PVs) PVs are devices which convert light directly into electricity. As a result of the doping one layer of silicon is negatively charged (n-type) and has a surplus of electrons. Cells with different characteristics and efficiencies can be created by using different base and doping materials. The capacity of cells to convert light into electricity is defined by watts peak (Wp). The efficiency of a cell is a function of both peak output and area. Some of the electrons are captured as useful energy and directed to an external circuit (Figure 7.2). Its Renewable Energy Law offered significant added value to the production of electricity from domestic PV roofs. In most common PV cells both layers are made from silicon but with different. This is based on a bench test and is the power generated by a PV under light intensity of 1000 watts per square metre. Its initial target of 100 000 PV roofs has been surpassed. This is a laboratory measurement and does not necessarily give a true indication of energy yield. The advantages of building integrated systems are: ● ● ● clean generation of electricity. Germany has been one of the frontrunners in promoting the application of PVs to buildings. The other layer is given a positive charge (p-type) and an electron deficit. The introduction of impurities is known as ‘doping’. As a result a number of national and international development programmes now exist to help exploit the opportunities offered. finely calculated amounts of impurities: p-type and n-type. The development of PV cells is gathering pace as indicated by the fact that the manufacturing capacity for PVs increased by 56 per cent in Europe and 46 per cent in Japan alone between 2001 and 2002. When light falls on a PV cell electrons are liberated by the radiative energy from the sun and able to migrate from one side to the other. generation at its point of use within the urban environment thus avoiding infrastructure costs and line losses.DOMESTIC ENERGY Power output is constrained by the availability of light falling on the cell. Converting to AC current involves a power loss.
A variation of silicon technology has been developed by Spheral Solar of Cambridge. Ontario. Tedlar or aluminium. molten silicon is cast in blocks containing random crystals of silicon. Due to the production processes involved these cells are expensive. To realise a usable amount of electricity cells are wired into modules which. in turn. The solar cell size of around 10 cm 10 cm has a peak output of about 1. That means that 15 per cent of daylight is converted to electricity when daylight is at its maximum intensity. Each sphere is therefore a miniature 82 . Polycrystalline silicon In the production process of this cell.5 watts. In appearance cells are blue and square. are electrically connected to form a string. One or more strings form an array of modules.2 Photovoltaic cell structure and function At the time of writing the most efficient PVs are monocrystalline silicon consisting of wafers of a pure crystal of silicon. It consists of 1 mm diameter silicon balls made from waste silicon from the chip making industry. It is cheaper than a monocrystalline cell but has a lower efficiency ranging between 8 and 12 per cent. It must be remembered that a number of linked cells produces a significant amount of current.ARCHITECTURE IN A CLIMATE OF CHANGE Solar radiation n-doped silicon Space-charge zone p-doped silicon Substrate backing Glass cover Electrodes Movement of electrons Figure 7. The cells are sandwiched between an upper layer of toughened glass and a bottom layer of various materials including glass. therefore during installation solar cells should be covered whilst all the electrical connections are made. The core of each sphere is doped to make it a p-type semi-conductor and the outer surface to make it an n-type semi-conductor. They achieve a peak output of about 15 per cent.
However. For example. However. In London it is 35 . This showed that the amount of electricity generated by a PV array rated at 1 kWp in one year varies considerably between different technologies. Standard PV modules can easily be fixed to an existing roof. costs range between £2 and £4 per Wp. if a roof covering needs to be replaced. in London 1 square metre of monocrystalline PVs could produce 111 kWh of electricity per year. It is the first of a new breed of PVs based on thin film technology. In summary. Different cells have varying optimum conditions which has been highlighted by a research programme recently completed by the Oxford University Environmental Change Institute. This is because these cells are more effective in the cloudy conditions so prevalent in the UK. It is planned to market it during 2005. At present prices are comparatively high but will reduce as volume of sales increases. provided it is not overshadowed by trees or other buildings. so it is very much a case of ‘buyer beware’. unit cost is not necessarily the only criterion. A sloping roof facing a southerly direction is the ideal situation. east and west orientations can produce significant amounts of electricity. The spheres are contained within a flexible aluminium and plastic matrix producing an effect similar to blue denim. Amorphous silicon This cell does not have a crystalline structure but is stretched into thin layers which can be deposited on a backing material which can be rigid or flexible. Double junction amorphous silicon cells were close behind. The system has a claimed efficiency of 11 per cent and can be formed to almost any profile. 83 . On low pitch or flat roofs it is advisable to mount the cells on tilt structures at the correct orientation. which should make it attractive to architects. However. a peak efficiency of 6 per cent is achievable. CIS (Seimens ST 40) gave the best returns at over 1000 kWh per kWp per year in the UK. The optimum angle of tilt depends on latitude. However. it then could become a cost-effective option to use solar slates.DOMESTIC ENERGY PV cell. As a rough guide. tiles or shingles to maintain a traditional appearance. having efficiencies of about 7 per cent and 9 per cent respectively. Unlike the crystalline cells it is capable of bulk production and is therefore potentially much cheaper. By building up layers tuned to different parts of the solar spectrum known as a double or triple junction cell. in the UK climate. The best performing modules produced nearly twice as much power as the lowest yielding cells. Single junction amorphous silicon cells were the poorest performers. a flat roof can still deliver 90 per cent of the optimum output. Cadmium telluride (CdTe) and copper indium diselenide (CIS) These cells are a further development of thin film technology.
Originally the intention was to use their power to meet the needs of the buildings. designed by Bill Dunster with Arup as the services engineers.4). It is important to ventilate PV cells since their efficiency falls as temperature increases. South London 84 .ARCHITECTURE IN A CLIMATE OF CHANGE A housing project which integrates PVs into its elevations and roofs is the Beddington Zero Energy Development (BedZED) in the London Borough of Sutton.4 Southern elevation. This requirement has been put to good use in a restaurant Figure 7. The problem was the extent of the expected payback time at current low energy prices. BedZED housing development. Their purpose is now to provide battery charging for a pool of electric vehicles for the residents which has the advantage of avoiding conversion to AC current (Figure 7.
See also Figure 18.5). p. This supplements demand at peak times and also bridges interruptions in the grid supply. A fan circulates air through a series of passages beneath the modules.5 Diagrams of PV heat recovery system (courtesy of CADDET) 85 . What makes this system special is the fact that warmth that builds up under the cells is harnessed to heat water which supplements space heating. the fan cuts in automatically to circulate heat away from the PVs and direct it in a closed loop to a heat exchanger. This technology will save the restaurant about $3000 per year in utility and hot water costs.16.. As solar heat builds up. USA. Its integrated roof system has 32 amorphous PV modules serving a 20 kWh battery facility. at the same time avoiding 22 680 kg of CO2 emissions (Figure 7.DOMESTIC ENERGY in North Carolina. 234.
It is often the case that the supply of electrical energy is not concurrent with demand. in the US PVs are now available from the Applied Power Corporation which deliver AC electricity which means they can be connected directly to the grid. an inverter must be employed. This offers an increasing range of facade options which might be exploited by architects to create 86 . An AC inverter is integrated with the cells (CADDET Renewable Energy Newsletter. March 2000). A major drawback at present is the price at which the utility companies purchase the excess PV production. In such situations two alternatives exist: either the excess power can be stored in some form of battery or used to heat water to be stored in an insulated tank to provide space heating. Since most uses of electricity require alternating current (AC). as stated earlier. A combination of high capital cost and miserly buy-in rates is seriously undermining the adoption of this technology by householders in the UK in contrast to Germany where subsidised demand is outstripping manufacturing capacity. currently about 5 p per unit as against the utility price of approximately 15 p. Pressure is mounting for the adoption of reversible meters that accumulate credit units from a renewable on-site installation but this is being resisted by some energy companies. though a sophisticated control system is required to ensure the output matches the grid phase. Photovoltaic panels would need active cooling in many building situations to maintain maximum output during summer months. Output is adversely affected by high operating temperature with a drop in efficiency from about 12 per cent at 20 C to about 10 per cent at 50 C. It may be easier to justify the cost of PV cladding materials for commercial buildings where occupancy patterns coincide with peak production levels. Alternatively it can simply be offloaded to the electricity grid. PV cladding materials can now be obtained in different patterns and colours depending upon the nature of the cells and the backing material to which they are applied.ARCHITECTURE IN A CLIMATE OF CHANGE Energy output The energy output from a monocrystalline cell varies with insolation level in an almost linear fashion across its operating range. if possible.. The preferred option in most urban situations at the present time is the grid-connected system. perhaps because of occupancy and use patterns. This also provides a backup supply when PV generation is insufficient. However. The UK has some of the worst buy-back rates in Europe. rear of the array. Clearly this is impractical and costly and at present the drop in efficiency has to be accepted.
energy used in the construction process. manufacture and transportation. materials used in refurbishment. However. 92 . which can lead to a wide band of values for similar products. It is clear. however. that the area of materials energy and environmental effect is one which can only grow in coming years. toxic substances used in the production process.ARCHITECTURE IN A CLIMATE OF CHANGE transportation of building materials and this is known as the ‘embodied energy’ and directly relates to the gross carbon intensity of a material. At the moment the consensus is that a building consumes much more energy during its lifetime than is involved in extraction. It is also a sphere where much more information is required in order to exploit opportunities associated with carbon taxes and other fiscal measures to improve design. A number of assessment tools and techniques are becoming available. The overall environmental credentials of a building are affected by a number of factors: ● ● ● ● ● ● ● ● energy used over its estimated lifetime. energy used in demolition. This arises from a natural reluctance on the part of manufacturers to disclose too much information about their commercial processes and also because of natural variations in techniques. it will increasingly be the case that the embodied energy will be a significant fraction of the total as buildings become more energy efficient. the presence of pollutants in a material such as volatile organic compounds (VOCs). level of recyclable materials at demolition. It can still be difficult to assess the full impact at present because of the scarcity of detailed information. the extent to which recycled materials have been used (see Chapter 18).
A development that meets all its electricity needs on site and therefore is not connected to the grid is an autonomous development. It is described as a net zero energy scheme which is defined as a development which is connected to the grid and there is at least a balance between the exported and imported electricity.2. it plans to be selfsufficient in vegetables. triple glazed internal windows and double glazed conservatory. 300 mm of insulation in walls. fruit and dairy products employing organicpermaculture principles.1 and 8. This is designed to be a partially autonomous scheme using recycled grey water and with waste products being aerobically treated by reed beds. The south elevation is completely occupied by a generous sunspace across all the units. A wind generator supplements its electricity needs.Advanced and ultra-low energy houses Chapter Eight Besides designing the Autonomous House in Southwell. the Vales designed a group of ultra-low energy houses at Hockerton in Nottinghamshire. It has a number of key features: ● ● ● ● ● ● ● ● ninety per cent energy saving compared with conventional housing. For example. self-sufficient in water with domestic water collected from the conservatory roof and reed bed-treated effluent for purposes that require the EU bathing water standard. 93 . There is an imbalance in cost for reasons stated earlier.4). roof-mounted photovoltaics. a wind generator will reduce reliance on the grid. One fossil fuel car is allowed per household and 8 hours’ support activity per week is required from each resident. seventy per cent heat recovery from extracted warm air.3 and 5. This is a narrow plan single aspect group of houses fully earth sheltered on the north side with the earth carried over the roof. Hockerton is a project designed for a special kind of lifestyle which will only ever have minority appeal. 5. considerable thermal storage due to earth sheltering. but it is important to demonstrate just how far things can be taken in creating architecture that harmonises with nature (Figures 8. This would not be to everyone’s taste.
1 Earth sheltered south and solar west elevations The Beddington Zero Energy Development – BedZED The Innovative Peabody Trust commissioned this development as an ultra-low energy mixed use scheme in the London Borough of Sutton. it had to stack up in financial terms.3). University of Nottingham (Figure 8. It is designed as a research facility and a flexible platform for the range of systems appropriate to housing. 1600 m2 of work space. all constructed on the site of a former sewage works – the ultimate brownfield site. nursery. The David Wilson Millennium Eco-House A demonstration Eco-House has been built in the grounds of the School of the Built Environment. organic shop and health centre. Though the Trust is extremely sympathetic to the aims of the scheme.ARCHITECTURE IN A CLIMATE OF CHANGE Figure 8. a sports club. Its features are: ● ● ● PV tiles integrated into conventional slates providing 1250 kWh/year. 94 . light pipe illuminating an internal bathroom and providing natural ventilation. It is described in detail in Chapter 18 ‘State of the art case studies’. Peabody was able to countenance the additional costs of the environmental provisions on the basis of the income from the offices as well as the homes. It consists of 82 homes. solar collectors of the vacuum tube type on the south elevation to meet the demand for domestic hot water.
designed by architects Robert and Brenda Vale Diverse plants and animals are encouraged 5. South Wales A competition winning ‘House for the Future’ has been designed by Jestico Wiles within the grounds of the Musuem of Welsh Life in 95 . Demonstration House for the Future.000 native trees have been planted and 60 species of birds recorded Each adult contributes 16 hours a week on tasks like organic gardening A wind turbine would provide electricity. plastic and cans are recycled 6 PVC-free wiring and pipes throughout house Eco-Balls used for washing clothes. helical wind turbine. not detergents Showers are fitted.ADVANCED AND ULTRA-LOW ENERGY HOUSES Five families teamed up to build the row of houses in Hockerton. and plan to buy an electic vehicle This house has a TV and Water saving WC Water pours from taps as in normal houses 6 Glass. Nottinghamshire. Associated with the Eco-House are several free-standing sun-tracking PV panels tilted to the optimum angle. Figure 8. ground source heat pump to supplement space heating.. Once treated it runs into the lake and becomes food for the fish The families try to walk and cycle rather than use cars.2 Hockerton overall life-style specification The output from the energy systems is constantly monitored..
It is capable of occupying a variety of situations: a rural location. As regards the plan. specially treated. Windows on the south elevation are designed to change according to the seasons of the year. Open living and daytime spaces face south whilst more private cellular spaces are on the north side.ARCHITECTURE IN A CLIMATE OF CHANGE Figure 8. Internally much of the space is defined by non-load bearing stud partitions. A superinsulated timber stud wall faced with oak boarding and lime render occupies three sides of the building. living space is fluid to accommodate the needs of different occupants. Nottingham University South Wales. The void between the timbers is filled with 200 mm of sheep’s wool. The structure of the house consists of a post and beam timber frame prefabricated from locally grown oak.6). a greenfield suburban site or high density urban sites in terrace form.16 W/m2K. This insulation is manufactured from recycled paper and treated with borax as a flame and insect retardant. The north facing roof is covered with sedum plants laid on a recycled aluminium roof.3 David Wilson Millennium Eco-House.4 to 8. There are some earth block partitions on the ground floor using clay found on the site. allowing total flexibility and adaptability. giving a U-value of 0. Considerable south facing glazing provides substantial amounts of passive solar energy.17 W/m2K. supplementing the thermal storage properties of the concrete floor slab. Cellulose fibre provides 200 mm of insulation between the deep rafters giving the roof a U-value of 0. Its two key attributes are sustainability and flexibility. All materials were selected with a view to minimising embodied energy (Figures 8. The 96 . These provide thermal mass.
Figure 8.5 Internal views obtained by Architectural Press .4 House for the Future – cross-section Figure 8.
15 units of heat. provided it is obtained from an accredited source such as the Forestry Stewardship Council.6 Ground and first floor 98 . The timber structure comprises a clear span gridshell formed out of a weave of oak laths. When renewable energy technologies become more affordable the house will become self-sufficient in energy. Edward Cullinan Architects in association with Buro Happold Engineers have produced an undulating structure which rhymes with the South Downs landscape. The Conservation Centre explores new techniques in greenwood timber construction. The Weald and Downland Open Air Museum 7 miles north of Chichester is a national centre for the conservation and study of traditional timber-framed buildings. Timber scores well on the sustainability scale. The house can contract as well as expand. Oak is twice as strong as an equivalent size of other timbers which means that the cross-section of members can be reduced. A pellet burning wood stove rounds off the space heating. This is the first timber gridshell structure in Britain and should become an icon of sustainable construction (Figure 8. Once the laths are in place natural drying strengthens the structure. The lower storey is temperature controlled to safeguard archival material. water conservation measures are an important component of its ecological credentials. The longest laths are 37 metres. Architects Glenn Howells won a competition for a visitor centre with a wave form grid structure that Figure 8. It is developments in glue technology which have made this possible. Space heating can be supplemented by a ground source heat pump fed by a 35 m bore hole. This should meet about 25 per cent of an average family’s demand. A central row of glue-laminated columns supports the floor of the workshop. The high moisture content of the timber allows it to be formed into the necessary curves and then locked into shape. Finally. Unique to the structure is the green jointing of the gridshell laths from freshly sawn oak. An even more ambitious gridshell structure is taking shape in Savill Garden in Windsor Great Park. The energy regime makes maximum use of both passive and active solar systems. Rainwater is collected in a specially enlarged gutter which can store 3 m3.ARCHITECTURE IN A CLIMATE OF CHANGE number of bedrooms can vary from one to five according to family needs. It is mechanically filtered and gravity fed to toilets and washing machine. A heat pump is driven by electricity but one unit of electricity produces 3. Roof-mounted solar collectors provide water heating for most of the year and a ridge-mounted wind generator and a PV array producing 800 W go some way to meeting the electricity demand. The structure is set on an earth sheltered masonry ground floor. Gas is not available on the site. The prospects for wood The House of the Future raises the question of the structural use of timber in buildings.7).
a plan-aspect ratio of c.8). platform timber frame. timber protected shaft.7 Interior of the Weald and Downland Conservation Centre (Edward Cullinan and Partners) differs from the Weald and Downland building in that it is raised above ground. This project has brought all aspects of construction together. allowing panoramic views of the park. including Regulations. the engineers involved at Weald and Downland.2:1. The results of the tests may well have a profound impact on the house building industry. The building comprises: ● ● ● ● ● ● four flats per floor. As a research exercise in multi-storey timber buildings. The report on the project concludes: This high profile project has provided a unique opportunity to demonstrate the safety. brick cladding. 99 . the Building Research Establishment Centre for Timber Technology and Construction has built a six-storey timber-framed apartment block as a test facility in its vast airship hangar at Cardington (Figure 8.ADVANCED AND ULTRA-LOW ENERGY HOUSES Figure 8. benefits and performance of timber frame construction technologies. It will be the largest gridshell structure in the UK at 90 m long and 25 m wide. using 80 by 50 mm larch timbers harvested from the Park with oak forming the outer rainscreen. single timber stair and lift shaft. The structure has been designed by Buro Happold.
BRE Garston) A tour de force of timber construction is the recently completed Sibelius Hall at Lahti in Finland. It is a testimony to the mastery of timber developed by the Finns over the centuries and serves to exemplify the versatility of this material as the ultimate renewable resource for construction. the Mosquito. (2003) Performance Assessment of Six-Storey Timber Frame Buildings against the UK Building Regulations. The architects are Hanna Tikka and Kimmo Lintula. Design. Construction and Whole Building Evaluation. V. It has been the most challenging and exciting opportunity to obtain technical backup data for promotion of timber frame in the last 20 years and it has been recognised as one of the most valued projects (Enjily. timber also has a good strength to weight ratio. As well as being a renewable resource.8 Building Research Establishment experimental timber-framed apartments Research. The advantage is this system is that it can accommodate curved and flowing shapes combining lightness with strength. codes and standards are being updated as a result of this project. The main structural element is laminated veneered lumber (LVL) typically 100 . This concert hall epitomises how timber used both as a structural and sheeting material can produce a building great elegance and beauty. The designers of this aircraft pioneered timber monocoque construction in which the skin and framework as a unified whole coping with both compression and tension. which is why it was used to construct one of the most famous aircraft of the Second World War. Many Building Regulations.ARCHITECTURE IN A CLIMATE OF CHANGE Figure 8.
9 Roof formation. the Maggie Centre. Dundee. RIBA Building of the Year for 2004 101 . Dundee (courtesy of RIBA Journal) Figure 8.10 Maggie Centre.ADVANCED AND ULTRA-LOW ENERGY HOUSES Figure 8.
11). The Winter Gardens form a spectacular element of the ‘heart of the city’ project for Sheffield (Figure 8. Sheffield 2002 (architects: Pringle Richards Sharratt) 102 . LVL was chosen for the roof of the Maggie Centre in Dundee.11 Winter Gardens. It is finished in stainless steel (Figures 8.ARCHITECTURE IN A CLIMATE OF CHANGE made from Norwegian spruce. Larch was chosen for its Figure 8. The most striking feature is the laminated larch parabolic arches which support the glass skin forming a counterpoint to the trees within. The contrasting space and architectural expression of the two buildings achieve the height of the poetic in urban terms.9 and. It opens at right angles to the Millennium Galleries that also integrate a pedestrian route with gallery and restaurant provision.10).
Vents in the roof and at both ends of the building encourage stack effect ventilation. many of which are under threat. Underfloor heating in winter is provided by the city centre district low grade heating scheme. C. The UK has one of the most turbulent climates in Europe. Trees such as Norfolk Island Pine and New Zealand Flax occupy the highest central zone of the space which rises to 22 m.5 m long and 22 m wide and designed to accommodate a wide variety of exotic plants.5 metres per second. A. In time it will turn a silvery grey. The external environment ● ● ● ● Wind Rain Solar shading Evaporative cooling. The space is 65. In the UK the average wind speed for 10 per cent of the time ranges from 8 to about 12. A useful guide to designing in timber is provided by Willis. This can create a pressure difference between the faces of a building: positive on the windward side and negative on the lee face. NATSPEC 3 Guide. In summer surrounding buildings will provide solar shading. (1998) Timber in Context – A Guide to Sustainable Use. This means that cold air tends to be forced into the windward elevation and warmth sucked out of the lee side (Figure 8. in a frost-free environment.12 Wind pressure and infiltration 103 . For the citizens of Sheffield it has been a spectacular success. and Toukin. the higher figures being in Scotland. The orientation of a property can have a significant impact on the extent to which it is adversely affected by wind. Positive pressure Infiltration Negative pressure Figure 8.12).-M.ADVANCED AND ULTRA-LOW ENERGY HOUSES durability and minimal maintenance characteristics.
Heated areas within the dwelling should be isolated from unheated spaces by providing insulation in the partitions between such spaces. remembering that deciduous trees are much less effective in winter. Some situations may allow for the protection afforded by earthberming and buffer spaces. the distance from a house to a tree break should be 4–5 times the height of the trees to optimise the dampening effect. 19 January 2003). average wind speeds increase by 7 per cent for every 100 m increase in altitude. Even low level planting creates drag. Wind plus driving rain can affect the thermal efficiency of a property. Trees are the best option. At the same time a timber fence of this nature will be less likely to become a casualty of gale force winds. Natural features can be effective wind breaks. On the other hand. The following are recommendations for minimising the use of energy and exploiting natural assets. According to the TV gardening personality Monty Don ‘In the British climate. A solid wind break can greatly reduce wind speed in its immediate vicinity but beyond that zone will cause turbulence. thereby slowing the wind force. Climatologists predict that global warming will result in wetter winters and much drier summers with droughts a regular occurrence. an openwork fence with only 50 per cent solid resistance to wind will moderate wind speed over a much greater area. wind is far more of a problem than sunshine and can be drought-inducing in the middle of winter when there is not a ray of sunshine to be seen for days’ (Observer Magazine. 104 . As a rule of thumb. Building features ● ● ● In considering the plan a compact building shape reduces heat loss. This problem would be cured with a polymer-based render. This gives shrubs and trees a further benefit in the degree to which they protect from the drying or desiccating effect of wind..ARCHITECTURE IN A CLIMATE OF CHANGE At the same time. Wind speeds can be considerably reduced by the introduction of natural or artificial dampeners.
High thermal mass construction levels out the peaks and troughs of temperature. In the design and positioning of windows the effect of solar gain must be considered in conjunction with daylight design. Where possible contours should be exploited either to maximise solar gain or minimise adverse effects. If metal frames are necessary there should be a thermal break between the frame and the glass. The detailing of joints in the building fabric can have a significant impact on energy efficiency. The heating of conservatories usually results in a net energy deficit. The built form ● ● ● ● ● ● ● The internal layout should place rooms on appropriate sides of the building either to benefit from solar heat gain or to avoid it where necessary. Care should be taken in the design of conservatories which should be able to be isolated from the main occupied area. The effect on heat gain of window frames and glazing bars can be significant. The provision of deciduous trees and shrubs will offer summer shade whilst allowing penetration by winter sun. As a general rule it is desirable to maximise south facing windows and minimise north facing windows. 105 .ADVANCED AND ULTRA-LOW ENERGY HOUSES ● ● ● ● ● ● ● Glazing must be low emissivity (Low E) double glazing. preferably in a timber frame. Areas with particular overheating risk should be considered when planning building layout and form. Internal surfaces should maximise solar heat absorption. at the same time account should be taken of probable air flow patterns. Areas of non-beneficial windows should be minimised. Air tightness should achieve a level of at most three air changes per hour at 50 pascals pressure in association with heat recovery ventilation. Potential cold bridges should be eliminated. Fabric insulation which is significantly better than the minimum required by regulation is strongly recommended. Passive solar heat gain External considerations: ● ● ● ● ● The main facade of a dwelling should face close to south ( 30 approximately). Shading (externally if possible) should be installed for windows posing overheating risk. The spacing between dwellings should be sufficient to avoid overshading.
The environmental benefits of conservatories are cancelled out if they are centrally heated. e. allowing power to be available on upper floors in times of flooding. Where there is a high standard of air tightness a heat recovery ventilation system is essential. Also linked to evolving climate change will be the need to take account of increased wind speeds. Climate change is predicted to increase the risk of flooding from a combination of rising sea level. Ventilation of utility areas. Systems ● ● ● ● ● ● ● ● ● ● Environmental considerations should be a priority when making the choice of fuel. High efficiency heating systems should be installed. for example: ● ● ● ● ● ● ● ● Most living accommodation should. and thermostats should be appropriate to the task and correctly positioned and their operation easily understood by occupants.ARCHITECTURE IN A CLIMATE OF CHANGE ● A conservatory or other buffer space can be used to preheat incoming ventilation air. Bathrooms should be on the first floor. The electrical circuit on the ground floor should be able to be isolated. and space heating and hot water systems should be appropriately sized. greater precipitation and river run-down. Power sockets should be at least at bench height. Ventilation grilles and air bricks should be capable of being sealed. programmers. bathrooms and kitchens is especially desirable to prevent condensation. where they are on the ground floor non-return valves should be fitted to WCs. Hot water storage cisterns and the distribution system should be effectively insulated. Windows sills should be at least 1 m above ground. In areas where there is the probability of flood risk special measures should be adopted. increased storm surges. tiled finishes.g. Floor and wall surfaces on the ground floor should be capable of recovery from flooding. heat episodes leading to 106 . Controls. extremes of climate. Door openings should be water tight for at least 1 m about ground. be on the first and upper floors. for example condensing boilers. The venting of hot air in summer should be considered. if possible. In wet central heating systems thermostatic radiator valves are essential. The heating system should be geared to the thermal response of the building fabric and occupancy pattern of the dwelling.
137). Swiss Re. orientation to present shorter elevation to prevailing winds. Natural ventilation will be counterproductive when outside temperature exceeds internal temperature. Consider more aerodynamic forms (e. On south facing elevations solar blinds will be essential. By 2080 internal temperatures could reach 40 C. Arup concludes that by 2080 London will have the climate of the Mediterranean coast and we should consider adopting similar building techniques to that region. Fitting louvres or external shutters to windows or internal blinds is recommended.ADVANCED AND ULTRA-LOW ENERGY HOUSES the drying out of ground at normal foundation level. It includes such points as: ● ● ● ● deeper foundations to cope with ground shrinkage. The answer could be removable or sliding heat reflective panels which reduce the glazed area in summer.g. A guide to revised building practices has been published as part of the government’s advice as to how business can respond to climate change. It recommends masonry buildings with high thermal mass over timber frame lightweight construction.) To conclude this chapter it is worth summarising points from an Arup report of Autumn 2004 on the likely impact of climate change on UK buildings. Smaller windows with shutters are recommended. It suggests that air conditioning and mechanical ventilation will be necessary. more robust walls and roofs to withstand intense storms. Where buildings are deficient in thermal mass a possible solution is to apply a phase change material to internal surfaces. Report by Arup Research and Development for the DTI’s Partners in Innovation Programme 2004 Points raised in the report relevant to housing Housing built to 2002 Building Regulations will be uncomfortably warm to live in by 2020. adding that the air conditioning should be driven by PVs or other renewable energy sources. 107 . 158–159). These are now becoming available in plaster form (see p. There is a conflict here with the principle of optimising passive solar energy. p. (DEFRA 2004.
Small wind turbines In this context ‘small’ means wind machines that are scaled from a few watts to 20 kW. measures must be taken to provide adequate strength in the building structure. Such conditions tend to favour vertical axis machines as opposed to the horizontal versions which have proliferated in wind farms. Currently the government is considering how to redress this inequity and thereby give a substantial boost to the market for small-scale renewables. In addition. horizontal axis machines mounted on roofs tend to transmit vibrations through the structure of the buildings. Wind patterns in the built environment are complex as the air passes over. By their very nature the vertical axis machines are not affected by changes in wind direction or turbulence. Machines between 1 and 5 kW may be used to provide either direct current (DC) or alternating current (AC). They can be sited on roofs or 108 . Small-scale electricity production on site has economic disadvantages in the UK given the present buy-in rates for small operators. This may not easily be achieved in retrofit situations.Chapter Harvesting wind and water Nine This chapter is concerned with wind generation which can operate as embedded generation in buildings down to the scale of the individual house and the conservation of water as the pressure on this resource increases. They are mainly confined to the domestic level and are often used to charge batteries. Accordingly a wind generator introduced into this environment must be able to cope with high turbulence caused by buildings. Wind generation will do well if this happens since it is much less expensive in terms of installed cost per kilowatt than PV which makes it an attractive proposition as a building integrated power source. This is because the vertical versions may be able to operate at lower wind speeds and they are less stressed mechanically by turbulence. around and between buildings. Because of the bending moment produced by the tower under wind load. The larger machines are suitable for commercial/industrial buildings and groups of houses.
they are still undergoing development.1 Helical side mounted turbine on oil platform 109 .HARVESTING WIND AND WATER walls. ‘wind sharers’ and ‘wind gatherers’. However. This is appropriate since climate change predictions indicate that wind speeds will increase as the atmosphere heats up and so becomes more dynamic. Currently there are several versions of vertical axis machines on the market. easy to install and competitive on price. The third type. The increasing deregulation of the energy market creates an increasingly attractive proposition for independent off-grid small-scale generation insulating the operator from price fluctuations and reliability uncertainties. They have been particularly successful mounted on the sides of oil platforms in the North Sea (Figure 9. The wind collector type of building has a lower profile and can be subject to turbulence.9). A prediction in ‘WIND Directions’. terms which define their effect on wind speed.1). March 2001. There is a fifth category. with the proviso that there is a level playing field. It is to be hoped that the bureaucrats fail to spot this red tape opportunity. This is where the vertical axis machine comes into its own. They are described as ‘wind catchers’. estimates that the global market for small turbines by 2005 will be around Euros 173 million and several hundreds of million by 2010. ‘wind collectors’. silent. in the Netherlands alone there is the potential for 20 000 urban turbines to be installed on industrial and commercial buildings by 2011. The wind generators continue operating at night when PVs are in retirement (see Figure 9. Their relatively even roof height and spaced out siting makes such buildings subject to high winds and turbulence. Ecofys has produced a diagram which depicts how four urban situations cope with varying wind conditions. the ‘winddreamer’ which relates to low rise developments (Figure 9. The machines are well balanced. Research conducted by Delft University of Technology and Ecofys identified five building conditions to determine their effectiveness for wind turbines. transmitting minimum vibration and bending stress to walls or roofs. For example. are found in industrial areas and business parks. There is growing confidence that there will be a large market Figure 9. They also have a high output power to weight ratio. A further advantage is that the electricity generator can be located beneath the rotors and therefore can be located within the envelope of the building. Small horizontal axis machines could be satisfactory in this situation. Development work is continuing on designs for turbines which are suitable for the difficult wind conditions found in urban situations. 114) by the system patented by Altechnica. wind sharers. low maintenance. Wind generation can be complemented by PVs as illustrated below (p. When it is fully appreciated that these machines are reliable. At present the regulatory regime for small turbines is much less onerous than for 20 kW machines. The wind catcher is well suited to small turbines being usually high and benefiting from a relatively free wind flow. it is likely the market will expand rapidly.2).
Systems under 2 kW usually have a 24–48 volt capacity aimed at battery charging or a DC circuit rather than having grid compatibility.2 Categories of building cluster and their effectiveness for wind generation (courtesy of Ecofys and REW) for mini-turbines in various configurations on offices. Types of small-scale wind turbine Most small systems have a direct drive permanent magnet generator which limits mechanical transmission losses. There are advantages to horizontal axis machines such as: ● ● ● ● the cost benefit due to economy of scale of production. automatic start-up. horizontal axis machines are much more in evidence that the vertical axis type even at this scale. Some even tip backwards in high winds adopting the so-called ‘helicopter position’. mounted on buildings they require substantial foundation support.ARCHITECTURE IN A CLIMATE OF CHANGE Figure 9. The disadvantages are: ● ● the necessity of a high mast. Up to the present. housing blocks and individual dwelling. 110 . high output. it is a robust and tested technology. These machines have efficient braking systems for when wind speed is excessive.
there are noise problems with this kind of machine especially associated with braking in high winds.5 kW and it is estimated that avoided fossil fuel generation produces a saving of 1. they can be visually intrusive. and there are plans for installations in four other primary schools.3 Helican turbine on a column at Earth Centre. vertical axis turbines are particularly suited to urban situations and to being integrated into buildings. Scotland. this necessitates frequent changes of orientation and blade speed. This has the effect of accelerating the air over the turbine blades. it also increases the dynamic loading on the machine with consequent wear and tear. It is regarded as an ideal system for residential developments (Figure 9. Glenrothes. Its peak output is 1. The Darrieus-Rotor employs three slender elliptical blades which can be assisted by a wind deflector. Produced by Renewable Devices Ltd. This is because the aerofoil concentrator enables the machines to produce electricity at slower wind speeds than is possible with conventional turbines. This not only undermines power output. The most common vertical axis machine is the helical turbine as seen at Earth Centre. The first unit was installed in Collydean Primary School.8 tonnes per year of carbon dioxide (CO2).4). as the name indicates. Another variety is the S-Rotor which has an S-shaped blade (Figure 9. Croatia. claims that this combination can produce electricity 60 per cent more of the time compared with conventional machines. In that instance it is mounted on a tower but it can also be side-hung on a building. Doncaster (Figure 9. As a result. Care has been taken to provide a secure mounting system which will not transfer vibrations. The cross-section of the cowling has a profile similar to the wing of an aircraft which creates an area of low pressure inside the cowling. more electricity is produced for a given wind speed as well as generating Figure 9. A variation of the genre is the H-Darrieus-Rotor with triple vertical blades extending from the central axis (Figure 9. the Swift wind turbine claims to be the world’s first silent rooftop mounted wind turbine (35 dB) by incorporating silent aerodynamic rotor technology coupled with a revolutionary electronic control system. As stated earlier.4). Doncaster 111 . A prototype developed at the University of Rijeka. Last in this group is the ‘Spiral Flugel’ turbine in which twin blades create. This is an elegant machine which nevertheless needs start-up assistance (Figure 9. They are discrete and virtually silent and much less likely to trigger the wrath of planning officials.3). Yet another configuration is the Lange turbine which has three saillike wind scoops (Figure 9.5). a spiral profile (Figure 9.6). A development from the 1970s has placed the turbine blades inside an aerofoil cowling.4).4).HARVESTING WIND AND WATER ● ● ● in urban situations where there can be large variations in wind direction and speed.
4 Left: S-Rotor. The answer has been to introduce hydraulically driven air release vents into the cowling which are activated when the pressure within the cowling is too great. Its manufacturers claim it could meet about 15 per cent of 112 . bottom centre: Lange turbine.ARCHITECTURE IN A CLIMATE OF CHANGE Figure 9. This amplification of wind speed has its hazards.5 Spiral Flugel rotor at low air speeds compared to a conventional rotor. top centre: DarrieusRotor.7 and 9. right: H-Darrieus-Rotor Figure 9. which makes them appropriate for urban sites.8). They also serve to stabilise electricity output in turbulent wind conditions. The device is about 75 per cent more expensive than conventional rotors but the efficiency of performance is improved by a factor of five as against a conventional horizontal axis turbine (Figures 9. It is being considered for offshore application. This technology can generate power from 1 kW to megawatt capacity. A mini horizontal axis turbine was introduced in late 2003 called the Windsave. It can generate up to 750 watts at an installed cost of £1 per watt. for example blades can be damaged.
Producing AC power it can be linked directly to the grid and the householder credited under the Renewables Obligation charges which currently pay a green electricity provider 6 p per kilowatt hour.HARVESTING WIND AND WATER Figure 9.7 Wind turbine with cowling wind concentrator the average household electricity demand. By using remote metering. Hamburg Figure 9. It starts generating at a wind speed as low as 3 mph but is most efficient at 20 mph. each unit can be telephoned automatically each quarter to 113 .8 Simulation of wind turbines on the Vivo shopping complex.6 Swift rooftop wind energy system Figure 9.
It is this subsidy which justifies a claim that the payback time can be as short as 30 months (Figure 9. Building integrated systems The Vivo building illustrates one version of a building integrated wind generating system. The advantage of this system is that it does not become an overassertive visual feature and is perceived as an integral design element. Up to now such machines have been regarded as adjunct to buildings but a concept patented by Altechnica of Milton Keynes demonstrates how multiple turbines can become a feature of the design. Furthermore it indicates a building which is discretely capturing the elements and working for a living. for 40 GW of wind power installed by Figure 9. The power company then collects the subsidy and distributes it back to the home owner on the basis of the total generated. There is increasing interest in the way that the design of buildings can incorporate renewable technologies including wind turbines. The flat top of the Solairfoil can accommodate PVs. The research has concluded that. Where the rotors are mounted at the apex of a curved roof the effect is to concentrate the wind in a manner similar to the Croatian cowling (Figure 9.ARCHITECTURE IN A CLIMATE OF CHANGE assess the amount of electricity generated.10 ‘Aeolian’ roof devised by Altechnica 114 . Rotors are incorporated in a cage-like structure which is capped with an aerofoil wind concentrator called in this case a ‘Solairfoil’. The European Union Extern-E study has sought to put a price on the damage inflicted by fossil fuels compared with wind energy.9). It is also a system which can easily be fitted to existing buildings where the wind regime is appropriate.10). The system is designed to be mounted on the ridge of a roof or at the apex of a curved roof section.
On average about 200 litres of rainwater fall on the roof of a 100 m2 house each day in the UK. The cumulative saving would amount to 320 million tonnes CO2 giving avoided external costs of up to Euros 15 billion.11 shows a typical configuration for rainwater storage. Figure 9. Recycled rainwater must only be sourced from roofs. However. there is also an energy component in storing and transporting it and making it drinkable. In many homes this is collected in water butts and used to irrigate the garden. Reducing consumption Flushing toilets use about 30 per cent of total household consumption. When the avoided costs of external damage are realistically factored in to the cost of fossil fuels.8 billion up to 2010. If filtered rainwater is to be used for other domestic purposes. usually by ultraviolet light.HARVESTING WIND AND WATER 2010. CO2 emissions could be reduced by 54 million tonnes per year in the final year. and with a total investment of Euros 24. A really thorough home ecological improvement strategy should have three components: ● ● ● reduce consumption. All appliances should have isolating stopcocks so that the whole system does not have to be drained off if one item has a problem. Storage tanks are either concrete or glass reinforced plastic (GRP). 115 . Conservation of water in housing Not only is water a precious resource in its own right. This is the first sign of a revolution in the way of accounting for energy. recycle grey water. it has wider uses. sinks and on shower heads make a big impact on consumption. harvest rainwater. Of this total about half is used for flushing toilets and personal hygiene. other than drinking. it must be subject to further purification. This is one of the factors which should influence the choice of white goods. There are several proprietary systems for collecting and treating rainwater so that it can be used to flush WCs and for clothes washing machines. An example is the Vortex water harvesting system which serves roof areas up to 200 m2 and 500 m2 respectively. Aerating (spray) taps on basins. Best use of the filtered rainwater will be made if associated with dual flush WCs. There are controls to ensure that mains water can make good any deficiencies in rainfall. the market should have no difficulty in switching to renewable energy en masse. This can be reduced by changing to a low flush toilet (2–4 litres) or a dual flush cistern. Washing machines and dishwashers vary in the amount of water they consume. On average a person in the UK uses 135 litres (30 gallons) of water per day.
demon. but this requires even more rigorous filtration. The Hockerton Housing Project has all these facilities and more because it uses rainwater collected from its conservatory roofs for drinking purposes. As an act of faith in the English weather there is no mains backup facility. A variation on the water recycling strategy is to reuse grey water from wash basins. Then it is sent through a carbon filter to remove dissolved chemicals. for example. as employed. For the really dedicated there is the composting toilet which eliminates the need for water and drainage. but those who feel inspired by this possibility should contact the Hockerton Housing Project at www. Again there are systems on the market which serve this function. In Europe a popular version is 116 . including water storage. 77). The water is stored in 25 000 litre underground tanks where particles have time to settle to the bottom. The water from the roof passes through a sand filter in a conservatory. then virtually all the waste water can be used to meet the needs of flushing toilets. showers and baths. Lastly it is subjected to ultraviolet light to kill bacteria and viruses. in the the Vales’ Southwell autonomous house (p. From here it is pumped to storage tanks in the loft and from there through a ceramic/carbon filter to the taps.hockerton.11 Rainwater storage system layout (courtesy of Construction Resources) 2 It is possible to go a stage further and use rainwater for drinking. The author can vouch for its purity! For the average home this may well be a step too far.uk. The water is treated first by passing it through a 5 micron filter to remove remaining particles. If waste water from a washing machine is included.co.
However. The by-product from the composting chamber is a rich fertiliser. should be given an energy efficiency rating from A to G. Refrigerators and freezers are particular culprits. A surprising amount of electricity demand is due to standby electrical consumption. the impact of appliances like white goods and TVs becomes a much more significant element of the energy bill. whilst A is the top of the scale there is variation within this category which has prompted the introduction of an AA category. Fan-assisted ducted air ensures an odourless aerobic decomposition process. nevertheless. Some appliances like televisions and personal computers have optional standby modes which. It has been estimated that a typical household could consume 600 kWh per year on standby alone. dishwashers etc. F and Gs to the bottom of the best buys. 117 . freezers.HARVESTING WIND AND WATER the Clivus Multrum from Sweden. are left on power because the consumption involved is regarded as insignificant. For the EU it has been calculated that standby power accounts for 100 billion kWh/year. about one fifth the consumption of a state the size of Germany. Domestic appliances As the building fabric of a home becomes more energy efficient. It is a two-storey appliance in that there has to be a composting chamber usually on the floor below the toilet basin. This has certainly been effective in sending E. Even appliances with electronic clocks consume power. Others. washing machines. refrigerators. like fax machines and cordless telephones need to be permanently on standby. In 1999 the European Commission decreed that all white goods.
It also takes into account benefits from solar gain. The International Energy Agency. If buildings are to contribute to carbon abatement in the short to medium term then existing buildings must be targeted. New homes complying with 118 . mainly houses.Chapter Existing housing: a Ten challenge and opportunity So far the emphasis has been on new buildings. This information is equated with the cost of making good the heat loss by means of the heating system and the cost of fuel. This will not only enable purchasers to compare older houses with new build but will also motivate vendors to upgrade their property in advance of a sale. Currently there is considerable interest in converting redundant industrial buildings to other uses. the real challenge lies in existing housing. which will include an Energy Efficiency Report. government improvement programmes were ‘unconvincing’ with ‘funding low in proportion to the magnitude of the task’. The UK government is introducing a requirement for houses that come on the market to be accompanied by a ‘House Condition Survey’. Its scale is from 1 to 120. the NHER profile. the BEPI profile. the carbon dioxide measure. especially residential. In England and Wales housing is responsible for about 28 per cent of total carbon dioxide (CO2) emissions. yet these comprise only about 2 per cent of the total building stock at any one time. It is scheduled to come into force in 2006. described UK housing as ‘poorly insulated’ with ‘considerable scope for improvement’. At the same time. What is the magnitude of the task? To gauge the scale of the problem we first need to consider the four accredited ways of measuring the energy efficiency of both existing and new homes: ● ● ● ● the SAP method. The official government system of measurement of energy efficiency is the Standard Assessment Procedure (SAP) which comprises a calculation of the heat loss resulting from the form of the building. the thermal properties of its fabric and the level of ventilation. which considers energy efficiency worldwide. However.
Within the 10 category the bottom end is as low as SAP minus 25. Thus it gives an accurate picture of the underlying condition of the housing stock. The current average for England overall is SAP 43. It is a performance indicator that gives an accurate reading of the energy efficiency of the total fabric and cannot be manipulated to gain a notional but unreal advantage. This is gradually improving as the ratio of new homes to existing increases.6 per cent of dwellings were at or below SAP 60 with 8 per cent at or below SAP 20. DETR 1996. 18 C. The unofficial recommended minimum for reasonable energy efficiency for existing homes is SAP 60. The English House Condition Survey 1996 found that 84. how does this translate into actual home heating habits? The official standard for adequate heating in a living room is 21 C and in other rooms. a carbon emission standard will be the only route to compliance. domestic hot water. For example. The Carbon Dioxide Profile indicates the carbon dioxide emissions deriving from the total energy used by a property taking into account the type of fuel. This constitutes a monumental problem which calls for constant pressure on governments to rise to the challenge of upgrading the housing stock.EXISTING HOUSING: A CHALLENGE AND OPPORTUNITY the Building Regulations according to the SAP method will probably have to be a minimum of SAP 100.0. 1. The national average NHER is around 4. December 2000).8 per cent of this sector being at or below SAP 10. The minimum heating regime is 18 C for the living room and 16 C for other rooms. It does not include heating systems and does not factor in the cost of energy. 3.8. However. So.3 million homes in England are at or below SAP 30. with 12. At present the amount of investment in this area of need is totally inadequate and it is being left to enlightened bodies like housing associations to take the initiative. in the private rented sector in England 21 per cent are at or below SAP 20. 119 . It is measured in kg/square metre/year.6 million are at or below SAP 20 and 900 000 are at or below SAP 10 (English House Condition Survey. this is a more accurate long-term measure of energy efficiency. since appliances and heating systems have a relatively short life and there is no guarantee that replacements will measure up to the previous standard. The Building Regulations standard equates to a BEPI of 100. Because this measure is confined to the efficiency of the building fabric. electricity has roughly four times the carbon intensity of gas. These numbers are substantially increased when Britain as a whole is considered. appliances and lighting and is designed to give an indication of energy costs. The Building Energy Performance Index (BEPI) assesses the thermal performance of the fabric of the building taking into account its orientation. In the revised Building Regulations 2005. To put some numbers against these standards. The National Home Energy Rating (NHER) uses a scale of 1 to 10. Only 25 per cent of homes have internal temperatures which meet these standards. and includes such items as the method of space heating. for a given unit of heat.
ARCHITECTURE IN A CLIMATE OF CHANGE When the external temperature drops to 4 C.6 tonnes in current best practice homes. the sick and the disabled most at risk. These figures are from the DETR House Condition Survey for England. The main culprit is cold. Many of the owner occupied homes are of 1930s vintage. 120 . We have the worst record in the EU for extra winter deaths. The definition is that they are unable to obtain adequate energy services for 10 per cent of their income. 62 per cent of council homes.7 tonnes of carbon dioxide. with children. About half of this total can be attributed to poor housing. A 1976 house which was the first to encounter thermal regulations will account for 2. How do they compare with today’s best practice? One crucial measure is carbon dioxide emissions. This figure may be significantly higher in that it is impossible to quantify the contribution of poor housing to depressive illnesses. In the winter of 1999–2000 almost 55 000 died from cold related illnesses between December and March as against the other two four monthly periods. poorly insulated and damp homes as acknowledged by the government in its document Fuel Poverty: The New HEES (DETR 1999): The principal effects of fuel poverty are health related. the old. Taking into account all fittings and appliances as well as the building fabric. The DTER acknowledges that fuel poor households also suffer from opportunity loss. Most of those energy services are of course taken up with space heating. There is a strong social dimension to this state of affairs. To achieve adequate space heating a 1930s house is responsible for 4. Cold homes are thought to exacerbate existing illnesses such as asthma and reduced resistance to infections. and 95 per cent of the private rented sector also fail to meet the minimum standard.6 tonnes of CO2 for space heating.. The UK government acknowledges that up to 3 million households in England are officially designated ‘fuel poor’. This was the highest winter total since 1976 yet it was a relatively mild winter. This compares with 0. then ● ● ● 50 per cent of owner occupied dwellings fail to reach the minimum standard. caused by having to use a larger portion of income to keep warm than other households. a superinsulated house with best available technology will produce a total of 2 tonnes of CO2 as against 8 tonnes in total for a 1930s dwelling.
op. The connection between housing and health has been recognised by the medical profession in a report Housing and Health: Building for the Future (eds Sir David Carter and Samantha Sharp. It was confidence in the connection between damp homes and asthma that justified the Cornwall and Isles of Scilly Health Authority in directing £300 000 via district councils to thermally improve homes of young asthma patients. At the opposite end of the country. 121 . installing/converting central heating to include a gas condensing boiler. An example of a retrofit package for housing would consist of: ● ● ● ● ● improving the level of insulation in walls and roof and. British Medical Association 2003). This was undertaken as much as an investment opportunity as a remediation intervention. almost a quarter of all homes suffer from damp in Scotland (National Housing Agency for Scotland). The outcome was that the savings to the NHS exceeded the annual equivalent cost of the house improvements. installing Low E double glazing preferably in timber frames. Increasingly damp as well as cold is emerging as a major health hazard.) This cost will taper off as the upgrading programme gathers momentum. The report on this enterprise. as in the genus Penicillium which can damage lung cells. states: ‘This study provides the first evaluation of health outcomes following housing improvements’. Some moulds are toxic. Spon) which should remove any doubts there may be about the linkage between poor housing and ill health. sponsored by the EAGA Trust. floor. where possible. cit. installing heat recovery ventilation system. The remedy There is no easy way to solve this problem and considerable investment will be required by central government if fuel poverty linked to substandard housing is to be eliminated. Rudge and Nicol. A book appeared in 2000 called Cutting the Cost of Cold (ed. draught-proofing. This is a thorough analysis of the situation from the medical standpoint. (Fuel Poverty: The New HEES. Damp generates mould and mould spores can trigger allergies and asthma attacks.EXISTING HOUSING: A CHALLENGE AND OPPORTUNITY This has adverse effects on the social well-being and overall quality of life for both individuals and communities. It will surely be the first of many since it provides hard evidence of cost effectiveness.
g. carrying it round window reveals means that the window frame size is reduced. The panels then receive a waterproofing finish.1). close to Building Regulations standard current at the time. roughcast. The application of external insulation. also called harling or wet cast. tile. internal dry lining. e. Cornwall. External cladding has a number of consequences.e.ARCHITECTURE IN A CLIMATE OF CHANGE From the architectural point of view the insulation is the main challenge. The addition of gas central heating raised the SAP to 76 which dramatically illustrates the effect of fixed appliances to the SAP value. the crucial BEPI rating was raised to 97. brick. The 1940s examples had a SAP rating of 1 and an NHER of 1. terracotta. was formed in 1994 to take over the local authority housing from Penwith District Council to make it possible to gain access for funds to upgrade the entire stock. Roof eaves and verges have to be extended and rainwater/soil vent pipes have to be modified to take account of the deeper eaves. filling the cavity. A polymer-based render is the most reliable in this respect. Case study Penwith Housing Association in Penzance. additional roof insulation and double glazing raised this to SAP 26. A mesh is applied to the insulation to provide a key for the external waterproof render which is finished with pebble dash (Figure 10. This is an adhesive render with an alkali resistant glass fibre mesh as reinforcement. The technique involves applying a render to provide an even and smooth fixing surface to the rigid insulation panels. It can take three forms: ● ● ● external overcladding (enveloping). However. This consisted of a mix of 1940s houses with solid concrete block walls and post-war cavity built homes. for example: ● ● ● pebble dash or spar dash. weatherboarding. In the case of most insulants the finish should offer total waterproofing. i. Applied in one or two coats it offers a choice of finishes. For example. 122 .1. It is also possible to use cladding which includes ● ● ● ● lightweight natural stone aggregate. textured renders in a range of colours. It is necessary for the insulation boards to receive a finishing coat. Being of concrete construction and rendered there was no problem as regards changing the appearance by overcladding.
Penzance 123 .1 Social housing with cladding over solid wall construction.EXISTING HOUSING: A CHALLENGE AND OPPORTUNITY Figure 10.
The incidence of condensation is reduced to near zero. Devon 124 . the alternative is to fix insulation to the inside face of external walls – ‘dry lining’. An example of an individual house application of external cladding is Baggy House in the UK which illustrates the ‘Dryvit’ system called ‘Outsulation’ (Figure 10. There should be absolute protection from penetration by damp.ARCHITECTURE IN A CLIMATE OF CHANGE Benefits ● ● ● ● ● ● ● ● ● ● ● There is a significant improvement in comfort levels throughout the whole house. The operation can be undertaken without the need to vacate the property. There is a significant reduction in carbon dioxide emissions. ensuring a longer life. over the lifetime of the building. The dilemma is that this reduces internal space. preventing cracking due to differential thermal expansion. Space heating bills can be reduced by up to 50 per cent. There is normally a significant improvement in appearance. Where there are overriding reasons for not wishing to overclad with insulation.2). To bring a 140 mm solid external wall near to the current Figure 10. The increase in property value as a result of the upgrading usually more than offsets the cost. The walls of the building are protected from weathering. Government estimates suggest that. in the case of eighteenth to nineteenth century terraced housing. for example. one tonne of CO2 is saved for every square metre of 50 mm thick insulation. as. It allows the fabric of the home to act as a heat store – a warmth accumulator. It stabilises the structure.2 Baggy House.
The team responsible for the innovative Integer House has been commissioned by Westminster Council to raise the energy efficiency of one of its 20 storey tower blocks as a demonstration of best practice in renovation. There are consequences to using this system. They have solid one and a half brick solid external walls and minimal insulation in the roofs.5 tonnes of CO2 emissions per year with a reduced fuel bill of £150 per year. In the Penwith 1960s properties. This is the kind of unromantic but challenging work which will have to be undertaken nationwide if the consequences of fuel poverty are to 125 . Some of the least energy efficient dwellings exist in multi-storey buildings. This could involve the replacement of external doors and windows. the most notorious being tower blocks. (For further information refer to Smith. Properly installed cavity filled insulation can have a significant impact on the thermal performance. P. Existing double glazing was considered adequate. Cavity filling Where there are cavity walls injecting insulation through holes drilled at regular intervals is a common practice. The 564 dwellings have been transferred to the Fortunegate Housing Association. The result is that on average each flat will save 1. Where central heating was installed the SAP rose to 78 again illustrating why the BEPI is a more useful guide to the long-term energy efficiency of a house since it focuses on the fabric. increased roof insulation. After consultation with the tenants PRP Architects agreed a specification including overcladding external walls with an insulated render system. such as the relocation of skirtings and electrical sockets and the reduced size of door and window openings. caution should be exercised regarding the kind of insulation selected and the bona fides of the installation contractor. full central heating with combination boilers. There is also the risk of cold bridging if the insulation is not continued around the reveals to openings. following cavity filling and extra roof insulation the BEPI was 107 with a SAP of 49.) The Roundwood Estate in Brent is typical of many former council developments with its numerous four storey flats and maisonettes linked by balcony access. This will be one to watch.EXISTING HOUSING: A CHALLENGE AND OPPORTUNITY Buildings Regulations standard would require at least 90 mm of insulation with a plasterboard finish. this is one instance where the best can be the enemy of the good and compromise is reasonable. Post-completion inspections have discovered a number of cases of fraud where only a notional amount of insulation has been injected. A suitable insulant is cellular glass fixed to the wall mechanically. Architectural Press. The finish is either plasterboard with a skim coat of plaster or plaster applied to metal lathing. (2004) Eco-Refurbishment: A Guide to Saving and Producing Energy in the Home.F. and new kitchens and bathrooms with extractor fans. At the same time comfort levels have substantially improved. However. However.
As a postscript to this chapter it should be noted that existing homes that are substantially refurbished are likely to need to comply with Part L of the Buildings Regulations. For new homes there are currently discussions about enhancing the energy efficiency scale to take account of zero carbon homes. existing and refurbished be overcome. At the same time. Part L is being revised and this will have the aim of achieving a 25 per cent improvement in energy efficiency.ARCHITECTURE IN A CLIMATE OF CHANGE Figure 10. so much abused in the past. As mentioned earlier. This will include an Energy Survey. the sole criterion for compliance will be based on carbon emissions which will close the loophole of the trade-offs. 126 . From January 2007 it is likely that houses for sale will require a Home Condition Report. Another change is that houses will be subject to air tightness standards and will have to submit to pressure testing.3 Roundwood Estate Housing Association flats. Refurbishment and overcladding is under way on this estate (Figure 10.3). An example of a considerable quantity of former council stock is the balcony access flats in the Roundwood estate.
Transport energy Avoiding unnecessary transport journeys during construction in terms of the delivery of materials and the removal of site waste.Low energy techniques for non-domestic buildings Chapter Eleven Design principles Offices in particular have traditionally been extravagant users of energy because. natural ventilation. In some cases. The aim of the architect under the sustainability banner is to maximise comfort for the inhabitants whilst minimising. reliance on fossil-based energy. Currently. The 1980s sealed glass box may use energy at a rate of over 500 kWh/m2/year. They are designed to validate or otherwise claims that buildings are ‘green’. delivery and construction stages. 3. Techniques such as high insulation. Embodied energy Minimising the carbon content of materials in the extraction. 1. energy is a relatively minor fraction of the total annual budget. on-site electricity generation and seasonal energy storage are components of the green agenda. natural light. In many cases the major electricity cost is incurred by lighting. manufacture. in relation to all other costs. Operational energy The energy consumed by a commercial building during its lifetime should be kept to a minimum. ultimately eliminating. passive and active solar optimisation. like the Wessex Water offices near Bath (see first edition) staff are 127 . best practice is in the region of 90 kWh/m2/year. thermal mass.. 2.
There is also the matter of location even though this will usually be outside the province of the architect. to avoid landfill costs. the design process should be a collaborative effort. costs are calculated in a composite manner so that capital and revenue costs are considered as a single accountancy feature. B. Biodiversity Design landscape to support local flora and fauna. There is now convincing evidence that ‘green buildings pay’ (see Edwards. Environmental considerations in the design of offices The first task is to persuade the clients of the benefits of environmental and energy efficient design. The first aim should be to maximise passive systems to reduce the reliance on active systems which use energy. 6. the outcome of an RIBA conference). Waste Minimising waste through greater off-site fabrication and modular planning. 4. Preserve existing mature trees and generally ensure the well-being of wildlife. (ed. even for buildings to be let or sold on. It is important that. etc. Integrated design principles should be the rule from the first encounter with a client. This has encouraged a much greater use of cars resulting in a net increase in carbon dioxide (CO2) emissions. ● ● ● It is important that all members of the design team share a common goal and if possible have a proven track record in achieving that goal. There have been instances where corporations have relocated from city centres accessible only by public transport to highly energy efficient offices on out of town sites. Sorting and recycling of off-cuts. This will help to convince clients that any extra capital expenditure is cost effective. 128 . 5. at the outset. Minimising hard areas to reduce run-off including permeable car park surfaces and porous paviors. From the earliest outline proposals through to construction and installation.) (1998) Green Buildings Pay.ARCHITECTURE IN A CLIMATE OF CHANGE obliged to use communal transport wherever possible. E & F Spon. Access to good public transport should be a prime requisite in deciding location. Water Harvesting grey water and rainwater for use in toilets and irrigation.
it is necessary to appreciate the degree to which solar access is available. At the earliest stage of design one must consider the following parameters in relation to the site: ● ● ● ● the sun’s position relative to the principal facades of the building (solar altitude and azimuth). occupant comfort and ease of operation and maintenance. the best compromise should be reached between optimum performance and the requirements for the majority of the year. proposed glazing types and areas. On completion building managers should be selected for their ability to cope with the complexities of the chosen building management system (BMS). so that the likelihood of solar heat gain can be determined. Energy costs should be identified with specific cost centres. 129 . At the same time. The cost of submeters. road layout and services distribution. Chapter 5 referred to the stereographic sun chart and computer programs as a means of assessing the level of insolation enjoyed by a building. For the development itself. Appropriate monitoring is necessary to be able to assess from day to day how systems are performing.LOW ENERGY TECHNIQUES FOR NON-DOMESTIC BUILDINGS ● ● ● ● ● Clients should be required to explain in detail the nature of office routines so that these can be properly matched to operational programmes. nature of internal spaces into which solar radiation penetrates. etc. Passive solar design Planning and site considerations Whether it is important to encourage or exclude solar radiation. To provide significantly greater capacity for just a few days of the year is not best practice. Physical models can also be tested by means of the heliodon. potential for overshadowing from obstructions outside the site boundary. the following factors need consideration: ● ● ● ● grouping and orientation of buildings. hoursrun recorders. existing obstructions on the site. give valuable returns for a small cost. and facade design. It is important to select appropriate technology which achieves the best balance between energy efficiency. site orientation and slope. The claims made for advanced technology do not always match performance. Lighting requirements should be clearly assessed to discriminate between general lighting and that required at desktop level.
i.ARCHITECTURE IN A CLIMATE OF CHANGE The thermal efficiency of a building can also be affected by its plan form and orientation in respect of the prevailing wind direction. The Ocean Terminal at Leith completed in 2001 is a good example of this technology. for example EDM Spanwall which uses flat metal sheets pressure bonded to the insulation core. the long axis should be parallel to the wind flow. but within each group the heights should be similar and spacing between them kept to a minimum (no more than about a ratio of 2 : 1 in building heights). Liverpool can boast a number of office buildings that point the way to the glass curtain wall such as Oriel Chambers in Water Street. curved facades moderate the impact of wind.uk).cwct. and even be dangerous. Sheer vertical faces to tall buildings can generate substantial downdraughts. protection for pedestrians can be provided by use of canopies and podiums which reduce downdraught at ground level. An example is the 19 storey Arts Tower in the University of Sheffield where the downdraught has knocked people over close to the entrance. The technique was conceived at a time when energy was cheap and plentiful and there was no glimmer of global warming. pp. Often these panels have an exterior finish of stone or reconstructed stone.e. Trent Concrete has introduced an insulated concrete sandwich under the name of Hardwall Cladding. for example the Swiss Re Offices. designed by Peter Ellis and completed in 1864. Tall buildings should. Buildings challenged the environment. where possible. Metal panel systems are now available with integral insulation.co. The repository for knowledge in this context is the Centre for Window and Cladding Technology (www. which can obstruct pedestrian access. Construction technologies The building envelope Walls and rainscreens The glazed curtain wall has advanced considerably since it came into vogue in the 1960s. though the feature first appeared in the US at the end of the nineteenth century. London. Now there is mounting pressure to design buildings which operate in harmony with nature. Precast concrete panels also come with integral insulation. making the most of 130 . Building layout should avoid creating a tunnelling effect between two adjacent buildings. have a facade which is staggered and stepped back away from the wind. Climate facades The glass curtain wall is a familiar feature of office and institutional buildings dating from the 1950s. Buildings can be grouped in irregular arrays. There are a number of guidelines: ● ● ● ● ● The larger building elevation should not face into the predominating wind direction. 157–58.
Then there is a 140 mm gap and a third inner leaf of glass with openable units which completes the facade. acts as an active and passive solar collector. The outer double glazed element is Low E glass with argon gas. and.5 m deep room.1 and 11. The active facade fulfils a variety of functions. facilitates heat recovery. An example of a climate facade building is the office development at 88 Wood Street in the City of London by the Richard Rogers Partnership (RRP). These are terms for facades that play an active role in controlling the internal climate of offices in which there is an optimum requirement for daylight. it acts as a solar collector. The shelf has a corrugated reflective 131 . in this case. When the blinds are closed they act as a heat sink whilst the perforations admit a measure of natural light. at the same time. a high services loading. offers excess solar heat protection. minimises room heat loss.LOW ENERGY TECHNIQUES FOR NON-DOMESTIC BUILDINGS solar resources. The result is that there are substantial savings in the energy normally needed to cool such spaces. serves as a plenum for ventilation supply and extract air. There is also a high rate of air change in the building at double the average for a typical office block (Figures 11. Now things have moved on with the incorporation of a second inside skin of glazing creating what is termed a ‘climate facade’ or alternatively an ‘active facade’. The facade developed by RRP and Ove Arup and Partners consists of a double glazed external skin made up of some of the world’s largest double glazed units measuring 3 m 3. the adjunct to the Houses of Parliament by Michael Hopkins and Partners. Another building with an active facade is Portcullis House.25 m and weighing 800 kg. The aesthetic appeal of the structure is enhanced by the use of extra white glass or ‘Diamond White’ glass by the manufacturers Saint Gobain. The requirement was for floor to ceiling glazing which can create a problem of solar gain which is exacerbated by the heat from computers and. Within the cavity are venetian blinds with perforated slats to control sunlight. The cavity is ventilated by room extract air. The result is a summer solar heat gain of less than 25 W/m2 across a 4. Air from the offices is drawn into the main perimeter extract ducts within the cavity via plenum ducts within a suspended ceiling and then expelled at roof level. Windows are triple glazed with mid-pane retractable blinds designed to absorb solar gain. The glazing incorporates a light shelf to maintain daylight levels when solar shading is active.2). The demand for increasing energy efficiency led first to the introduction of double glazing. It: ● ● ● ● ● ● offers room daylight control. Photocells on the roof monitor light conditions and control the venetian blinds to one of three positions according to the level of glare.
1 Offices. 88 Wood Street. A sealed facade does not mean the individual user has no control over ventilation. This almost doubles daylight levels in north facing rooms where adjacent buildings obstruct a view of the sky (Figure 11.ARCHITECTURE IN A CLIMATE OF CHANGE Figure 11. City of London Figure 11. 132 .2 Sections through the facade of 88 Wood Street surface to maximise high altitude sky light but reject short wave low level radiation. There are manual trim controls over air supply.3).
The Solar Offices of Doxford International by Studio E Architects located near Sunderland is a pioneer example of this tactic in the UK. The case study of the ZICER building in the University of East Anglia will serve as an example (Chapter 18). This is a speculative office development which offers the advantage of much reduced power consumption of 85 kWh/m2/year as against the normal air conditioned office of up to 500 kWh/m2/year. The main advantage of commercial application is that offices use most of their energy during daylight hours. Based on this figure it is expected that the cost of the PVs will be paid back in three years thanks to a substantial subsidy. The Doxford Office is modest compared with the German government In-service Training Centre called Mont Cenis at Herne Sodingen in the Ruhr.5). The 73 kW (peak) array of over 400 000 photovoltaic cells on the facade produces 55 100 kWh per annum which represents one third to one quarter of the total anticipated electrical consumption (Figures 11. blinds. This is an outstanding example of a building that minimises reliance on services engineering. Commercial buildings have perhaps the greatest potential with PV cells integrated into their glazing as well as being roof mounted. designers should now be able to grasp the opportunities offered by such technologies which also allow exploration of a range of new aesthetic options for the building envelope.LOW ENERGY TECHNIQUES FOR NON-DOMESTIC BUILDINGS volume. To date it has achieved an average daily output of 150 kWh. After this it will continue to produce electricity free of cost for about 20 years. It is claimed that the integrated approach to the design has resulted in simplified engineering solutions and a considerable saving in energy as against a standard naturally ventilated building. One of the challenges of the next decades will be to retrofit buildings with PVs. Ove Arup and Partners estimate that one third of the electricity needed to run an office complex could come from PVs with only a 2 per cent addition to the building cost. radiator output. This will increasingly be a preferred option as the cost of fossil fuel rises under the twin pressures of diminishing reserves and the need to curb CO2 emissions. It is estimated that the annual saving in CO2 emissions from this building alone will be of the order of 6 tonnes. Given the abundance of information and advice available.3 Portcullis House. In the UK a pioneer scheme is the Northumberland Building for the University of Northumbria in Newcastle where cells have been applied to the spandrels beneath the continuous windows.4 and 11. cutaway section of facade 133 . artificial lights and a daylight dimming override. Even at the present state of the technology. Currently the Co-Operative Headquarters building in Manchester is retro-fitting PVs to the south elevation of its circulation tower as part of a refurbishment programme. Figure 11. Another kind of active facade is one which incorporates solar cells.
in effect. a giant canopy encompassing a variety of buildings and providing them with a Mediterranean climate.5 Interior. The structure encloses two three-storey buildings either side of an internal street running the length of the building (Figure 11.7).6). balancing out 134 . A timber structural frame of rough hewn pine columns is a kind of reincarnation of the forests from which they originated..ARCHITECTURE IN A CLIMATE OF CHANGE Figure 11.4 Doxford Solar Offices Figure 11.. The building is. Their concrete structure provides substantial thermal mass.
balancing output fluctuations. These provide a peak output of 1 megawatt. Six hundred converters change the current from DC to AC to make it compatible with the grid.LOW ENERGY TECHNIQUES FOR NON-DOMESTIC BUILDINGS Figure 11. The power generated greatly exceeds the 135 . The roof and facade incorporate 10 000 m2 of PV cells integrated with glazed panels.5 per cent.6 Mount Cenis In-service Training Centre. Sections of the facade can be opened in summer to provide cross-ventilation. Germany Figure 11.7 Mount Cenis ground floor plan both diurnal and seasonal temperature fluctuations. Two types of solar module were employed: monocrystalline cells with a peak efficiency of 16 per cent and lower density polycrystalline cells at 12. The building is designed to be self-sufficient in energy. Herne – Sodingen.2 MW battery plant stores power from the PVs. Landscaped spaces provide social areas which can be used all year in a climate akin to the Côte d’Azur. A 1.
which then. Air is passed through the ducts at low velocity with stale air drawn into grilles over light fittings and then its heat extracted in a heat recovery unit before being expelled to the open air. Paris. Traditionally concrete plank or slab floors had ceilings suspended below them to house services. The former mines in the area release more than one million cubic metres of methane which is used to provide both heat and power. during the day. Such thermal mass features are sometimes called ‘thermal flywheels’ or dampeners since they flatten the peaks and troughs of temperature. One of the most aesthetically and environmentally suitable methods of achieving radiative thermal mass is by barrel vaults. Capturing the gas in this way results in a reduction of carbon dioxide emissions of 12 000 tonnes. Concepts in Practice – Energy. there is an alternative which is to use a phase change material on internal 136 . German policy on renewables makes exporting to the grid a profitable proposition. The soffit of the concrete floor is free of finishes. A proprietory deck system which incorporates ducts to transport both warm and cool air is Termodeck from Sweden. It all adds up to an enchanting environment of spaciousness. as employed in Portcullis House (Figure 11. Floors and ceilings The undersides of floors have a crucial role to play in determining the effective thermal mass of a structure. Jourda and Perraudin. Whilst the popular way to moderate the peaks and troughs of external temperature as it affects building interiors is to exploit thermal mass. This complex is an outstanding example of an alliance between green technology and aesthetics.ARCHITECTURE IN A CLIMATE OF CHANGE needs of the building at 750 000 kWh per year. light and shade. a thermal bridge is a route whereby cold is able to bypass wall insulation. This was used in the Elizabeth Fry Building in the University of East Anglia to good effect. night air is passed through ducts to cool the slab. In summer.8) and Wessex Water Operational Centre near Bath by Bennetts Associates. 1999. For further information see Smith and Pitts. Batsford. There is no recirculation of air. It is important that the slabs are not carried through to the facade in order to avoid a major thermal bridge. At the same time it affords a graphic reminder that regenerated industrial landscapes do not have to be populated by featureless utilitarian sheds. The architects. radiates cooling into the workplace. the purpose being to improve the effectiveness of the thermal mass and radiate stored heat in colder temperatures and ‘cooling’ in hot conditions. designed the distribution of PV panels to reflect the arbitrary distribution of clouds by means of six different types of module with different densities creating subtle variations to the play of light within the interior. To recapitulate. Now there are increasing examples of the system being reversed with the floor above the slab raised to provide space for ducts and other services. This is not the only source of energy generation. yet this is one of the most energy efficient buildings of the 1990s due to very high levels of insulation and air tightness.
8 Vaulted floors with exposed soffits. It is based on paraffin wax which is a phase change material. As the wax stores heat its temperature does not rise until it reaches melting point which is its maximum storage capacity. A system is now on the market which enables lightweight structures to enjoy the benefits of thermal mass. This makes the system particularly suitable for offices which are vacant at night and which can be vented to the outside.de). It is claimed that a plaster coating of 6 mm has the same absorbent capacity as a 225 mm masonry wall.fraunhofer. Portcullis House surfaces. The wax is micro-encapsulated within gypsum plaster. The wax stores heat up to its melting point. The mix is sprayed to walls.LOW ENERGY TECHNIQUES FOR NON-DOMESTIC BUILDINGS Figure 11. 137 . Up to spring 2004 ten buildings have been equipped with the system which was developed by the Fraunhofer Institute for Solar Energy Systems in Freiburg (e-mail: schossig@ise. reducing or even eliminating the need for mechanical ventilation. The wax is encapsulated within minute plastic balls to form microcapsules in powder form which is mixed with plaster in a ratio of between 1 : 5 and 2 : 5 by weight. In an office context this material is ideal for facing internal partitions. This can be adjusted to a range of temperatures according to the requirements of the material that supports it. Night-time cooling causes the wax to solidify and release the stored heat to warm the interior space.
colder air is drawn in to compensate: the buoyancy principle. In most office situations this can be considered as a supplement to the main ventilation strategy. Internal air flow and ventilation Air flow in the interior of buildings may be created by allowing natural ventilation or by the use of artificial mechanical ventilation or air conditioning. depth should be limited to about two and a half times the floor to ceiling height. Natural ventilation is possible due to the fact that warm air is lighter than cold air and therefore will tend to rise in relation to cold air.Chapter Ventilation Twelve Natural ventilation Part of the reaction against the sealed glass box concept of offices has been to explore the possibilities of creating an acceptable internal climate by natural means. Openings on opposite walls to allow cross-ventilation are better than on one or more adjacent walls. The overriding principle should be to minimise the need for artificial climate systems and one way to achieve this is to make maximum use of natural ventilation in conjunction with climate sensitive design techniques for the building fabric. The most straightforward system of cross flow ventilation is where fresh air is provided with routes through a building from the windward to leeward side. If air flow is to be encouraged to help provide natural ventilation and cooling the following are desirable design features: ● ● ● ● Plan form should be shallow to allow for the possibility of crossventilation. As it rises. For single sided ventilation. 138 . The production of buildings using more than one of these options is becoming more frequent. This has caused a reappraisal of traditional methods including those employed in hot climates for two millennia or more. Building depth should not be more than about five times the floor to ceiling height if cross-ventilation is to be successful. Such buildings are said to be ‘mixed-mode’.
VENTILATION ● ● ● ● ● Minimum opening areas should be about 5 per cent of floor area to provide sufficient flow. admirably demonstrates this technology (Figures 12.1 Portcullis House. thus reducing internal heat gain. 12. Windows should be openable. is drawn in at high level assisted by the thermal wheel (Figures 12. Figure 12. If the chimney has a matt black finish it will absorb heat and increase the rate of buoyancy.1 and 12. In fact this building is one of the most overt demonstrations of the dynamics of natural ventilation. A thermal chimney which is warmed by the sun accelerates the process.11). The effectiveness of natural ventilation and cooling can be improved by the use of low energy controlled lighting and low energy office equipment. Fresh air. Portcullis House. with external rising ducts carrying the warmed air from the offices to a thermal wheel on the roof before being expelled. The ventilation system most obviously borrowed from the past is the use of the thermal chimney exploiting the buoyancy principle. causing cooler air to be drawn into the building at ground level. in this case.13). Continuous. Atria and vertical towers can be incorporated into the design to allow the stack effect to draw air through the building.11. London 139 . but able to provide controlled air flow. though care in meeting fire and smoke movement restrictions may determine the limits of what is possible.12 and 12. secure background ventilation should be available using trickle vents and other devices. Westminster. 157–159). This is particularly difficult in high rise buildings but its problems have been addressed in the 40 storey Swiss Re building in the City of London (see pp.
In a building relying solely on the buoyancy of natural ventilation. By now the air has reached 18 C. E & FN Spon. control is critical. R.4).ARCHITECTURE IN A CLIMATE OF CHANGE Unassisted natural ventilation Pioneers of natural ventilation are Alan Short and Brian Ford in association with Max Fordham. The buoyancy of rising warm air draws fresh air into plenums below floor level to the base of each light tower. This building has been well documented and a particularly useful reference is Thomas. The environmental strategy was developed in association with Brian Ford. From here the air is drawn upwards through preheating coils to be released to rooms at floor level. The air is then drawn into the exit stacks spaced around the external walls.2). by architects Short and Associates. ‘Termination’ devices at the top of the stacks ensure that prevailing winds will not push air back down the stacks (Figures 12. The solution was to provide each quadrant of the floor plan with large lightwells doubling up as air delivery shafts.) (1996) Environmental Design. Their first groundbreaking building in the UK was the Queen’s Engineering Building at Leicester de Montfort University (Short Ford and Partners). Maintaining the principle of pure natural ventilation without mechanical assistance is the Coventry University Library.2 Coventry University library (courtesy of Marshalls plc) 140 . Accordingly perimeter windows are sealed (Figure 12. There is also the problem of a raised ring road close to the site generating noise and pollution. (ed. This is a deep plan building making it impossible to employ cross flow ventilation from perimeter windows.3 and 12. the Lanchester Building. The building energy management system (BEMS) Figure 12. Additional warmth is provided by perimeter radiators.
Coventry University library 141 .3 Plans.VENTILATION NW SE SW FIRST FLOOR PLAN VENTILATION STACK ROOF PLAN Figure 12.
ARCHITECTURE IN A CLIMATE OF CHANGE Section through central atrium (air outlet) Warm Exhaust air out Section through perimeter lightwell (air inlet) Fresh Air intake Figure 12.4 Air circulation paths 142 .
It is tuned to meet the optimum fresh air requirement compatible with the minimum ventilation rate (Figure 12. Manchester University 143 . learning by its mistakes. This is a BEMS which is driven by a self-learning algorithm.5).VENTILATION adjusts the outlet opening sizes according to outside temperature and the CO2 and temperature readings in each zone of the building. The building type which presents the most formidable challenge to anyone committed to natural ventilation is a theatre. meaning that it should progressively optimise the system. The latter comprise Low E double glazing with an argon filled cavity.0 W/m K for windows. There is a considerable heat load from stage lighting as well as the audience yet the Contact Theatre at Manchester University achieves comfort conditions without help from air conditioning. This is around 85 per cent less than the standard air conditioned building. The BEMS controls dampers which allow night air to flow through the building.4). Figure 12. Heat losses through the fabric of the building are minimised by good insulations standards: U 0. This is another building by which Alan Short.26 W/m2K for walls and less than 2 2. Brian Ford and Max Fordham have navigated uncharted waters (Figure 12. cooling the exposed thermal mass during the summer.5 Contact Theatre. Short Ford Associates have risen to the challenge in a spectacular fashion. The result of avoiding mechanical ventilation and maximising natural light is that the estimated energy demand is 64 kWh/m2 per year which represents CO2 emissions of 20 kg/m2.
6). Their volume is calculated to accelerate the buoyancy effect and draw out sufficient hot air whilst excluding rain. In a theatre ventilation and cooling are the major energy sinks. The H-pot design lifts them above neighbouring buildings to exclude downdraughts from the prevailing south-west winds. which has been largely preserved.ARCHITECTURE IN A CLIMATE OF CHANGE The outstanding feature is the cluster of H-pot stacks over the auditorium reaching a height of 40 metres. Consequently the energy load of this building should be a fraction of the norm (Figure 12. Contact Theatre 144 .6 Longitudinal and transverse sections. Things were made more complicated by the fact that this is a refurbishment of a 1963 auditorium. Figure 12.
One objection to naturally ventilated buildings is that they draw polluted air into a building.VENTILATION In circumstances like this theatre it may be necessary to incorporate attenuators in the system to minimise external noise. A wind vane ensures that the terminal always faces the correct direction. There is considerable variation in the relative temperatures over the diurnal and seasonal cycle. Night-time cooling works when the external temperature is lower than the internal one and gravity drives the cooler air down into the building. night-time cooling can be achieved by passing large quantities of fresh air over the structure. The exhaust air can either exit through perimeter ducts or a climate facade. The ventilation 145 . To reduce the chance of this happening in highly polluted areas. In the UK this system can work economically up to six storeys. These led to a low pressure mechanical system linked to heat recovery via a thermal wheel which recovers 84 per cent of the exhaust heat. Figure 12.9). Westminster. exhaust air which has risen through the stack effect also needs to be expelled at high level. At the same time. The mechanical system requires 51 000 kWh per year and this is supplied by 450 m2 monocrystalline photovoltaic cells. so a means has to be found of ensuring the exhaust air does not contaminate the fresh air. Mechanically assisted ventilation Rotating cowls was the system adopted by Michael Hopkins and Partners with Ove Arup and Partners in the Nottingham University Jubilee Campus (Figure 12. the fresh air is delivered through perimeter ducts to provide displacement ventilation. If heat is transferred from the input duct to the exhaust duct. above the diesel particulate matter zone. The stack effect or gravity displacement is dependent on the difference in temperature between the outside and inside air and the height of the air column. One way is to employ a terminal design which rotates according to the direction of the wind.7 a design of terminal is shown which ensures that fresh air is always drawn in from the windward side and exhaust air to the leeward side. perhaps by evaporative cooling or a heat pump. it is necessary to cool the incoming air.8. In the section. fresh air should be drawn into the building at high level. This ventilation system is the successor to Hopkins’ and Arup’s innovations at the Inland Revenue HQ also in Nottingham. assisting the expulsion of exhaust air. and Portcullis House. The aerofoil shape of the wind direction terminal produces negative pressure on the leeward side. In Figure 12. During the summer. this further assists buoyancy. In the daytime in summer when the internal temperature has become lower than the outside temperature. Above this duct sizes may become excessively large to cope with the volume of air.
10). More precise control over air temperature and humidity can be achieved this way but usually only within a sealed 146 . Air conditioning involves the cooling of the air using a refrigeration system.ARCHITECTURE IN A CLIMATE OF CHANGE Figure 12. Mechanical assistance should not be confused with air conditioning which is a much more complex operation. Air is introduced directly into the roof mounted air handling units where it passed through electrostatic filters. A degree of mechanical assistance is necessary to achieve an adequate rate of movement around the building. as in the traditional oast houses of Kent (Figure 12. Exhaust air uses the corridor as the extract path from where it rises under low pressure via a staircase to the roof air handling unit (AHU) for heat recovery then expelled through the cowl.7 Combined function rotary terminal system uses 100 per cent fresh air throughout the year. Mechanical ventilation involves air flow and movement provision using fans and air and possibly supply/extract ducts. However. From here it is blown down vertical shafts into traditional floor voids and thence to teaching rooms via low pressure floor diffusers. no cooling system is incorporated and therefore the lowest air temperature which can be supplied is usually restricted to ambient conditions. In most commercial and institutional buildings it is unlikely that natural ventilation on its own will be adequate. The vane on the cowl ensures that the extract vent faces the leeward side according to the direction of the wind. in its basic form. Such a system may be able to act as the heating system in winter.
VENTILATION Figure 12.10 Air handling units (AHUs) Jubilee Campus 147 .8 Typical system for a naturally ventilated office Figure 12.9 Jubilee Campus.
direct evaporative cooling is best in dry climates where average relative humidity at noon in summer does not exceed 40 per cent.15 Directed evaporative cooling.) (1996) Environmental Design. R. Figure 12. Jubilee Campus 153 . (ed. evaporative cooling is produced if incoming air to a building passes over a dampened surface. and transferred to the vapour. E & FN Spon). This heat is removed from the water. The amount of heat required to change water into vapour is the latent heat of evaporation. but can be allowed to pass through tubes or pipes which have their outer surfaces moistened. Evaporative techniques include: ● ● ● ● ● air that does not already have a high moisture content can be cooled by allowing water to evaporate into it. Orientation ensures that the prevailing wind is in the right direction (Figure 12. An example of a design which incorporates evaporative cooling is the Jubilee Campus at Nottingham University. Sloping glazing directs air which has previously passed across an extensive open air pool into an atrium between teaching and office units. as stated. the air does not come into direct contact with the moisture. in the case of indirect evaporation. or through a spray or damp material across windows. So. direct evaporation occurs when air passes through tree foliage. evaporation causes surfaces to cool (Thomas.VENTILATION liquid state. hence ‘evaporative cooling’. fountains and across pools.15).
To cope with the wind speeds (up to 40 metres per second at 18 storeys) he uses wing wind walls and wind scoops which deflect the wind into the centre of the building. a 60-storey three-sided building wraps round an open central core ascending the full height of the building (Figure 12. This began life as a limited competition for an office headquarters comprising 900 000 square feet of office space and 500 000 square feet of other uses. However. Also the construction energy costs rise significantly every five floors or so. Tower blocks usually require a heavy engineering services system. At that time the Green Party was in control of the city. The natural ventilation enters through the top of the gardens passing into the central atrium. The brief was clear that it should be an ecological building in which energy efficiency and natural ventilation played a crucial role. The gardens feature vegetation from North America. the ecological tower block has its advocates. at the same time causing minimum interference with external views. In the winning design by Norman Foster Associates. In traditional Mediterranean building. we can learn from this.16).17).ARCHITECTURE IN A CLIMATE OF CHANGE Additional cooling strategies ● ● ● Shading should be compatible with daylight provision and passive solar gain. The nine gardens each occupy four storeys and rotate round the building at 120 degrees enabling all the offices to have contact with a garden. The first manifestation of these principles in the west was the Commerzbank in Frankfurt (Figure 12. The ecological tower Surely an oxymoron? The orthodox ‘green’ would rule out anything above about 12 storeys since this is the height at which natural ventilation in the western European climate zone is said to become impracticable. He pioneered the idea of gardens in the sky coupled with natural ventilation. Japan and the Mediterranean according to their height above ground. the outer surfaces were painted light colours to reflect a portion of the heat gain. The atrium is subdivided into 12-storey units and within 12 floors there is cross-ventilation from the gardens in 154 . The gardens are social spaces where people can have a coffee or lunch and each one ‘belongs’ to a segment of office space accommodating 240 people. The most remarkable feature of the design is the incorporation of open gardens. As the architects put it: ‘we’re breaking the building down into a number of village units’. most notably Ken Yeang from Kuala Lumpur. This is extremely important in reducing the scale of the place for its occupants. Use heat absorbing and heat reflecting glasses.
the building management system activates a backup 155 . Air quality is good. It is estimated that the natural ventilation system will be sufficient for 60 per cent of the year.16 Commerzbank.VENTILATION Figure 12. Frankfurt Figure 12.18). When conditions are too cold. enhanced as it is by the greenery.17 Commerzbank typical floor plan the three directions (Figure 12. windy or hot.
The 39th floor is a restaurant offering spectacular views for the privileged few.19–12. The idea of an atrium space easily accessible at all levels has now evolved into six spiral light wells that have a platform at every sixth floor. The curved aerodynamic shape ensures then even high winds slide off the surfaces making minimum impact. a thermal chimney.ARCHITECTURE IN A CLIMATE OF CHANGE ventilation system which is linked to a chilled ceiling system that operates throughout the building. presumably from the airport. The inner skin of the facade is Low E double glazing giving the overall system a high U-value.21). The question is whether this is a piece of architectural whimsy or a form that arises from a logical functional brief. the energy Figure 12. Overall the ventilation system is mixed mode employing air conditioning which is perhaps inevitable in a building of this height and location. which is. There is no doubt as to its genetic origin which is the Commerzbank in Frankfurt with its triangular plan and four-storey atria which rotate around the plan (Figures 12. Air enters at each floor in the facade into a 200 mm cavity where it heats up and passes out through the top of the cavity. The climate facade consists of a 12 mm glass outer skin that has been specially coated to absorb radar signals. in effect. providing natural ventilation for 40 per cent of the year. If the Greens had not had their brief moment of glory it is likely that this building would never have happened. was completed (Figure 12. The atria/lightwells provide natural ventilation and act as ‘lungs’ for the building. It is claimed by its architects Foster and Partners to be the first environmental skyscraper in the City. Floors between the break-out spaces have balconies to the atria. has made it possible to incorporate motorised opening windows in the atria to assist natural ventilation. Motorised aluminium blinds in the cavity provide solar shading. The curtain wall design is on Klimafassade (climate facade) principles. It also demonstrates how bioclimatic architecture is subject to the vagaries of political fortune.19). It is calculated that the ventilation system will use only 35 per cent of the energy of an air conditioned office. At 40 storeys its circular plan and conelike shape differentiate it from all other high buildings in London. This. the London headquarters of the international reinsurers Swiss Re.. According to the services engineers Hilson Moran. in turn. However. This is a remarkable attempt to create an extremely high tower block which minimises its environmental impact whilst also providing optimum comfort and amenity for its occupants. Triangular in plan they serve to provide both light and ventilation. In 2004 Number 30 St Mary Axe.18 Natural ventilation paths in the Commerzbank 156 . The spirals are accentuated in darker glass on the elevation.
The external skin is a climate facade consisting of an external double glazed external screen and single internal glazing. namely that a bespoke building may only be partly used by the building owner. removing warm air in summer and providing insulation in winter. The space between serves as a ventilated cavity. Altogether the environmental attributes of the design result in an estimated energy consumption of 150 kWh/m2 per year which represents a 50 per cent saving compared with a traditional. fully serviced office development of similar size. A circular plan has the advantage of maximising daylight in the office floors which are situated around the perimeter with circulation taking up the core of the building. Solar controlled blinds are positioned within the cavity.19 Swiss Re Insurance Group headquarters. London impact of the air conditioning is reduced by a series of heat recovery units. This building highlights one of the dilemmas of bioclimatic architecture. good practice design. In this case Swiss Re will undertake rigorous energy 157 . Both natural and mechanical ventilation systems are controlled by an intelligent building management system.VENTILATION Figure 12.
Again the design makes maximum use of the climate facade principle which adds about 3 per cent to the cost and reduces the floor plate. much of the tower will be let out with no guarantee of a similar quality of energy management. it should produce a two thirds energy saving against a conventional sealed air conditioned equivalent.ARCHITECTURE IN A CLIMATE OF CHANGE Figure 12. in Aldgate. Up to the seventh floor occupants can open windows behind a protective glass screen. The worst case scenario is that the system will be allowed to default to air conditioning which will negate the energy efficiency targets of the designers. However. Like the previous examples in the book this will maximise natural ventilation as part of a mixed-mode ventilation strategy within the constraints of a high rise building. Nearby.20 Ground floor plan and piazza Figure 12. reckon that if the natural ventilation capacity is used to the full. Roger Preston and Partners.22). Nicholas Grimshaw and Partners are constructing a 49-storey office building. The services engineers. Above this level the climate facade comes into its own.21 Upper floors with triangular atria management. This moderates the problems associated with high rise buildings: high wind velocity. offering considerable revenue benefits thereafter. When the energy savings are capitalised it quickly becomes clear that the extra cost is soon recovered. the Minerva Tower (Figure 12. The natural ventilation works by allowing occupants to operate double glazed windows which open into a 650 mm space sealed from the outside by a single skin of 158 . pollution and noise.
with mechanical ventilation only necessary in extremely hot.VENTILATION Figure 12. This means that. The seasonal variations in the operation of the climate facade are shown in Figure 12. cold or windy conditions. 159 . air velocity can be moderated by vents. Vents at the top and bottom of this void allow access for fresh air. even at a height of 200 m.23.22 Minerva Tower glazing. The designers are optimistic that the tower will be able to operate in natural mode for about two thirds of the year. allowing it to enter the office space at an agreeable velocity.
Cool the structure of building using cooler air normally available at night. Consider the use of solar chimneys to enhance stack air movement. Wind towers and wind catchers can be used to derive additional air flow. oscillating and ceiling types – should be available when alternative air flow is insufficient. Radiative loss of heat ● Radiant heat loss from building surfaces can be improved by consideration of the geometry of the building in relation to the sky and other structures. Plan the siting of building openings to enhance natural ventilation. Minerva 2 Summary Ventilation and air movement – recommendations ● ● ● ● ● ● ● ● Help cool occupants by increasing air movement during day time. Internal fans – box. 160 . Absorption of heat gain ● ● ● Absorption cooling uses natural sources of heat to drive simple absorption refrigeration systems.23 Natural ventilation in a climate facade. Lithium bromide and ammonia-based refrigerants are most frequently used.ARCHITECTURE IN A CLIMATE OF CHANGE Figure 12. Heat is removed from the building by air or liquid cooled by the absorption system. Investigate the use of wing walls to improve air flow through openings. Allow stack effect flow paths to produce ventilation air movement.
prior to supply to the building. usually one to three metres below the surface. thus requiring heavy duty energy guzzling fans.VENTILATION ● Exposed roof surfaces may allow night-time cooling in suitable climates. 161 . Earth cooling strategies ● ● The temperature of the earth below ground is generally cooler and more stable than the air above ground. The earth is used to absorb heat either by building wholly or partly underground or by passing air through ducts or passages. it likely to be of prime importance in only a fraction of the whole building and therefore designers should design for appropriate compartmentalisation with the conditioned area sealed from the remainder of the building. Where air conditioning is deemed necessary. The system is often operated for large fractions of the day when a suitable building design combined with an appropriate environmental control strategy would obviate the need for such air conditioning. The extravagant use of air conditioning is particularly noteworthy in the temperate climate of the United Kingdom. There are of course some circumstances in which air conditioning is necessary. However. Air conditioning Air conditioning systems have high energy demands for heating and particularly cooling systems. In general it can be asserted that climate-sensitive design can eliminate the need for air conditioning in most instances. In addition the rates of air flow are often substantially higher than with simple mechanical ventilation systems. The additional proportion of energy consumption is not matched by a proportional increase in comfort. its use should be justified by the particular circumstances.
It is worth noting the relative CO2 emissions between different forms of fossil-based energy: kg/kWh delivered 0. Primary energy is that which is contained in the fuel in its natural state. Even at the current price of energy green buildings can be cost effective. it is around 30 per cent efficient. At present fossil-based energy is relatively cheap because.75 0. It can be one of the more efficient ways of using energy. yet still electricity accounts for 750 grams of CO2 in the atmosphere for every kilowatt hour. it does not carry its external costs such as the damage to health. to buildings and above all to climate. as delivered energy.Chapter Energy options Thirteen Electricity is the ultimate convenience source of energy which disguises the fact that. it is highly energy inefficient. delivered energy is that which is in the fuel at the point of use. A typical distribution of total energy output from a CHP system is Electricity High grade heat Medium grade heat Low grade heat 25% 55% 10% 10% 162 . as indicated earlier.31 0. to forests.21 Electricity Coal Fuel oil Gas Much has been made of the UK’s switch to gas fired electricity generation. It may soon become politically necessary to incorporate these costs into the price of fossil fuels which will have huge economic consequences. An increasingly popular way of servicing commercial and institutional buildings is by combine heat and power (CHP). Energy is defined as ‘primary’ and ‘delivered’. with present methods of production and the fuel mix. Meanwhile the biggest carbon dioxide (CO2) abatement gains are to be realised in cutting demand especially in buildings. At its point of use.28 0. that is.
there is no reason why they shouldn’t 163 . However. It is a reactor which combines hydrogen and oxygen to produce electricity. There will also be considerable reductions as mass production begins to bite. The fuel cell is not an energy storage device but may be considered as an electrochemical internal combustion engine. According to David Hart of Imperial College ‘If fuel cells fulfil their potential. At present the most cost-effective way to obtain the hydrogen is by reforming natural gas. A CHP system is flexible. The reason for this cost difference is that the fuel cell uses platinum as a catalyst. experts think that the quantity of platinum can be cut by a factor of 5. 41). According to Amory Lovins ‘A reformer the size of a water heater can produce enough hydrogen to serve the fuel cells in dozens of cars’ (New Scientist. This is the technology of the future. Each installed kilowatt costs $3000 to $4000. usually hydrogen. It can be adapted to low to zero carbon applications.ENERGY OPTIONS This is called the ‘energy balance’ of CHP and it is attractive for two main reasons: ● ● Most of the energy of the fuel is useful. clean and quiet with no moving parts and are ideal for combined heat and power application. heat and water. At present most CHP installations operate with gas or diesel reciprocating engines or turbines for larger installations. Unlike batteries they take their energy from a continuous supply of fuel. The fuel cell Fuel cells are electrochemical devices that generate DC electricity similar to batteries. p. Considerable research effort is being directed into improving the efficiency and lowering the cost of fuel cells because this is the technology of the twenty-first century and huge rewards await whoever makes that breakthrough. Fuel cells are efficient. For static cells in buildings perhaps the most promising technology is the solid oxide fuel cell which operates at around 800 C. The latest prediction is that the cost should fall to between $600 and $1000 per kilowatt. Later in the decade there will probably be a considerable rise in the use of fuel cells. 25 November 2000. whereas a combined cycle gas turbine system costs $400 per kilowatt. even relatively small installations will soon be able to switch to gas fired micro-turbines. In that case it will not be long before it will be possible to buy a fuel cell and reformer kit for the home which will make it independent of the grid providing heat and power much more cheaply than is possible at present. The problem at the moment is that it is an expensive way of producing energy. Thus its environmental credentials are impeccable. which will bring about a significant reduction in cost. Most fuel cells work with hydrogen. However.
The catalyst on the anode causes the hydrogen to split into its constituent protons and electrons. Inside Science ‘Fuelling the Future’. The cell consists of an anode and a cathode separated by an electrolyte. The electrolyte membrane allows only protons to pass through to the cathode setting up a charge separation in the process.7 volts then recombining with protons at the cathode to produce water and heat (Figure 13.2). This is one of the most common types of cell being appropriate for both vehicle and static application.2 Fuel cell stack 164 . 16 June 2001). which have integral channels to allow the free flow of hydrogen and oxygen (Figure 13.1). At present there are five versions of fuel cell technology. Figure 13. Hydrogen is fed to the anode and an oxidant (oxygen from the air) to the cathode.ARCHITECTURE IN A CLIMATE OF CHANGE replace almost every battery and combustion engine in the world’ (New Scientist. usually graphite.0 kW/kg for internal combustion engines. The electrons pass through an external circuit creating useful energy at around 0.1 Basic structure and function of the proton exchange membrane fuel cell Figure 13. Both the anode and cathode are coated with platinum which acts as a catalyst. Proton exchange membrane fuel cell Sometimes called the polymer electrolyte membrane fuel cell (PEMFC in either case) it is also referred to as the solid polymer fuel cell. usually Teflon. To build up a useful voltage cells are stacked between conductive bi-polar plates.3 kW/kg compared with 1. The proton exchange membrane system is the most straightforward and serves to explain the basic principles of the fuel cell. Of all the cells in production it has the lowest operating temperature of 80 C. The electrical efficiency of the PEMFC is 35 per cent with a target of 45 per cent. Its energy density is 0.
It employs a phosphoric acid proton conducting electrolyte and platinum or platinum–rhodium electrodes. while power companies will use them as alternatives to extending the electricity grid. from 2 to 1000 kW. However. It potentially has a wide range of power outputs. This technology seems particularly popular in Japan where electricity costs are high and dispersed generation is preferred. UK.ENERGY OPTIONS One problem with the PEMFC is that it requires hydrogen of a high degree of purity. it is likely that its future lies in stationary systems. Its high temperature also removes the need for noble metal catalysts such as platinum. cooling. but this is expected to improve. PAFC units have been used experimentally in buses.). op. The main difference from a PEMFC is that it uses a liquid electrolyte. Surrey. light and dehumidification for the Pool in the Park recreation centre. It also has a capacity of 200 kW and provides heat.’ An example of this is the police station in Central Park. Phosphoric acid fuel cell (PAFC) Similar to PEMFCs this cell operates in the middle temperature range at around 200 C. cit. It is a high temperature cell. Its great virtue is that it can run on a range of fuels including natural gas and methanol which can be reformed within the cell. running at between 800 and 1000 C. One year after this prediction the Borough of Woking. which found that installing a PAFC of 200 kW capacity was cheaper than a grid connection requiring new cables in the park (David Hart. This means it can tolerate some impurities. installed the first commercial PAFC fuel cell to operate in the UK. A 200 kW unit which uses sewage gas provides heat and power for Yokohama sewage works. The largest installation to date for the Tokyo Electric Power Company had an output of 11 megawatts – until it expired. The fuel cell forms part of Woking Park’s larger combined heat and power system (see p. Its high operating temperature also enables it to break down impurities. The system efficiency is currently in the 37–43 per cent range. 242). The 165 . Research activity is focusing on finding cheaper and more robust catalysts as well as more efficient ion exchange polymer electrolytes. Solid oxide fuel cell (SOFC) This is a cell suitable only for static application. taking several hours to reach its operating temperature. New York. In contrast to PEMFCs the electrolyte conducts oxygen ions rather than hydrogen ions which move from the cathode to the anode. static fuel cells will become attractive for hotels and sports centres. The New Scientist editorial referred to above predicts that ‘Larger.
Air (oxygen) flows through a central tube whilst fuel flows round the outside of the structure (Figure 13. According to David Hart of Imperial College ‘Solid oxide fuel cells are expected to have the widest range of applications. Smaller units could be used in houses. Large units should be useful in industry for generating electricity and heat. The electrolyte in this case is an alkaline mixture of lithium and potassium 166 . Alkaline fuel cells (AFC) This fuel cell dates back to the 1940s and was the first to be fully developed in the 1960s.3 Solid oxide fuel cell in its tubular configuration electrolyte is a ceramic which becomes conductive to oxygen ions at 800 C. its energy density is merely one tenth that of a PEMFC which makes it much bulkier for a given output. However. Its operating temperature is 60–80 C which enables it to have a short warm-up time. SOFCs are often structured in a tubular rather than a planar form (as in the PEMFC) to reduce the chance of failure of the seals due to high temperature expansion.ARCHITECTURE IN A CLIMATE OF CHANGE Figure 13. Molten carbonate fuel cell (MCFC) This is a high temperature fuel cell operating at about 650 C. It was used in the Apollo spacecraft programme. It employs an alkaline electrolyte such as potassium hydroxide set between nickel or precious metal electrodes.3).
Research is concentrating on solutions to this problem. Until that is available a catalyser within 167 . will make them attractive for domestic combined heat and power. International Fuel Cells (US) is testing a cell producing 5 kW to 10 kW of electricity and hot water at 120–160 C for heating. which. The car would be fuelled by a hydrogen grid. The MCFC can achieve an efficiency of 55 per cent. Every home could have a combined heat and power plant running off mains gas’ (New Scientist. the initiator of the fuel cell in his West Beacon farm. . The researchers consider that cars will be the main beneficiaries of the technology. The Energy Research Corporation (ERC) of Danbury. considers a scenario whereby the fuel cell in a car would operate in conjunction with a home or office. USA. if successful. This innovative cell uses a copper and cerium oxide catalyst instead of nickel. Professor Tony Marmont. 18 March 2000). is marketing as the ‘GE HomeGen 7000’ domestic fuel cell. has built a 2 megawatt unit for the municipality of Santa Clara. That prediction should perhaps be raised to 2010. This is a residential system which the US company Plug Power. The operation of the MCFC differs from that of other fuel cells in that it involves carbonate ion transfer across the electrolyte. thinks differently. The electrodes are both nickel based. Development programmes in Japan and the US have produced small prototype units in the 5–20 kW range. Kevin Kendall.ENERGY OPTIONS carbonates which becomes liquid at 650 C and is supported by a ceramic matrix. The steam and carbon dioxide it produces can be used to drive a turbine generator (cogeneration) which can raise the total efficiency to 80 per cent – up to twice that of a typical oil or gas fired plant. In March 2000 it was announced that researchers in the University of Pennsylvania in Philadelphia had developed a cell that could run directly off natural gas or methane. The cell can consume hydrocarbon fuels that are reformed into hydrogen within the cell. This makes it tolerate both carbon monoxide and carbon dioxide. According to him ‘Millions of homeowners replace their gasfired central heating systems in Europe every year. Within five years they could be installing a fuel cell that would run on natural gas . a chemist from the University of Keele. He estimates that a car spends 96 per cent of its time stationary so it would make sense to couple the car to a building to provide space and domestic hot water heat. . Consequently this technology could be ideal for urban power stations producing combined heat and power.85 megawatt plant. and that company is currently developing a 2. The main disadvantage of the MCFC is that it uses as electrolytes highly corrosive molten salts that create both design and maintenance problems. However. California. which is linked to General Electric. It did not have to be reformed to produce hydrogen. The electricity generated would be sold to the grid. Connecticut. Other fuel cells cannot run directly on hydrocarbons which clog the catalyst within minutes.
petrol. In Portland. Perhaps the greatest beneficiaries will initially be rural communities in developing countries who could never hope to get access to a grid supply. In the US there are growing problems in some areas over the reliability of the power supply and this is increasing the attractiveness of fuel cells. The reason for the intensification of research activity is the belief that the fuel cell is the energy technology of the future in that it meets a cluster of needs. The fuel cell will really come into its own when it is fuelled by hydrogen produced from renewable sources like solar cells. A cheap fuel cell powered by hydrogen electrolysed from PV. propane and other hydrocarbons to produce hydrogen would still result in massive reductions in carbon dioxide emissions and pollutants like oxides of sulphur and nitrogen. 168 . underground methane or water split by PV/wind electrolysis then this programme will certainly be one to be emulated by all industrialised countries.. In the meantime reforming natural gas. The same happens in California where sewage from the Virgenes Municipal Water District in Calabasas reforms methane into hydrogen to supply a fuel cell that provides 90 per cent of the power needed to run the plant. It could also relieve us of reliance on a national grid which. At present this is one of the main stumbling blocks to a pollution-free future. There is little doubt that we are approaching the threshold of the hydrogen-based economy. wind.and marinebased renewables.6). The US Department of Energy plans to power two to four million households with hydrogen and fuel cells by 2010 and ten million by 2030. Access to energy is the main factor which divides the rich from the poor throughout the world. If tidal energy is exploited to its full potential there will be peak surpluses of electricity which could serve to create hydrogen via electrolysis. not least the fact that it can be a genuine zero carbon dioxide energy source. If the hydrogen is obtained from sewage. Ultimately hydrogen should be available ‘on tap’ through a piped network.ARCHITECTURE IN A CLIMATE OF CHANGE the car would reform methanol or even natural gas from the mains to provide the hydrogen. in many countries. is unreliable. The domestic-scale fuel cells will have built-in processing units to reform hydrocarbon fuels and the whole system will occupy about the same space as a central heating boiler. If it were available to the grid it would power 300 homes. livestock waste. solar-electric or small-scale hydroelectricity could be the ultimate answer to this unacceptable inequality. Oregon hydrogen extracted from methane from a sewage works generates power sufficient to light 100 homes. Fuel cells reliant on renewable energy will be heavily dependent on an efficient electricity storage system.
The Japanese are taking the technology further by developing a levitating flywheel using high temperature superconducting ceramics to repel magnetic fields. An experimental project is underway on the Isle of Islay which is also the site of the pioneer wave energy projects (Chapter 3). Larger-scale operations need pressures of 500–600 bar. but this requires cooling to 253 C which is highly energy intensive. Energy can be drawn off by the permanent magnets in the disc inducing an electric current in a coil. Braking energy is used to power a flywheel which then supplements acceleration energy. Up to 50 litres can be stored at 200 to 250 bar. Production costs will be considerably reduced due to its patented onestop manufacturing process.ENERGY OPTIONS The main barrier to the widespread adoption of fuel cells is the cost. If situated in a vacuum. Hydrogen storage Hydrogen has an image problem thanks to regular replays of the Hindenberg disaster. Metal hydrides such as FeTi compounds store hydrogen by bonding it chemically to the surface of the material. p. The metal is charged by injecting hydrogen at high pressure into a container filled with small particles. 169 . 13 July 1991. The development thrust. It plans to have domestic-scale fuel cells on the market in 2005. It can be liquefied. Its true potential lies in the storage of energy over a much longer term and in larger quantities as friction problems are overcome. A UK firm ITM Power of Cambridge is claiming that it should be able to reduce this to ~$100/kW by developing a simplified fuel cell architecture based on a patented unique family of ionically conducting polymers which are cheap to produce. Storage techniques – electricity Flywheel technology The use of flywheel technology to store energy has been pioneered in vehicles. the energy loss over a 24 hour period would be negligible (New Scientist. 28). A complete fuel cell stack would be made in a single process. The traditional storage method is to contain it in pressurised tanks (see Freiburg House. however. The flywheel is made to rotate by electromagnetic induction to a speed of 3600 revolutions per minute which represents an energy storage capacity of 10 000 watt hours. Bonded hydrogen is one of the more favoured options. has come from space technology. Figure 16). The US Department of Energy estimates that the current cost of a fuel cell is ~$3000 per kilowatt. In this form it has a high energy to mass ratio – three times better than petrol but it requires heavily insulated tanks.
One of the challenges of the next decades will be to retrofit buildings with PVs. It converts electrical energy to chemical energy which is reversible and is capable of storing massive amounts of electricity. Ove Arup and Partners estimate that one third of the electricity needed to run an office complex could come from PVs with only a 2 per cent addition to the building cost. Reference was made earlier to the solar offices at Doxford with its complete southerly facade supporting 400 000 PV cells. a hotel. Of the 12 000 m2 of roof. and Pitts. (1997). 10 000 m2 are 170 . National Power in the UK is constructing a 360 GJ installation with a rated power output of 15 MW which will feed directly into the grid. In Chapter 11 the example of the Mont Cenis training centre in Germany was cited as an ambitious use of PVs. Given the abundance of information and advice available. The hydrogen is released as the heat and pressure dissipate.4). A pioneer example is the Northumberland Building for the University of Northumbria in Newcastle where cells have been applied to the spandrels beneath the continuous windows (see Smith. much more ambitious PV programmes have been carried out on the continent. offices and a library. designers should now be able to grasp the opportunities offered by such technologies which also allow exploration of a range of new aesthetic options for the building envelope. Batsford). These are contained within a glazed envelope 180 m by 72 m and 16 m high. principally an Academy for Further Education.C. Even at the present state of the technology. The case study of the Zicer building in the University of East Anglia will serve as an example (Chapter 18). In the opinion of the Royal Commission on Environmental Pollution.ARCHITECTURE IN A CLIMATE OF CHANGE The hydrogen bonds with the material producing heat in the process. It is a multi-use complex. However. P. A. The main advantage of commercial application is that offices use most of their energy during daylight hours. Concepts in Practice Energy. The most extensive use of PV technology has been in the commercial and institutional sector. Regenerative fuel cell A technology which is about to receive its first large-scale demonstration is based on a technology called ‘Regenesys’. hydrogen and regenerative fuel cells will be in widespread operation by the middle of the century. If global warming and security of energy supply issues simultaneously become critical then viable large-scale storage technologies will arrive much sooner.. More recently the technology has been incorporated into an atrium roof at Nottingham University’s Jubilee Campus (Figure 13. Photovoltaic applications Commercial buildings have perhaps the greatest potential for PV cells to be integrated into their glazing as well as being roof mounted.
The Sunpower Corporation is manufacturing a solar cell which achieves an efficiency of over 20 per cent as verified by the US National Renewable Energy Laboratory. They exploit the principle that 171 . Earthscan 1999).8 per cent in 2002 with most going to grid connected supply in Japan. the impact on the electricity market could be dramatic with the potential for every home to become a micro-power station. Germany and California. The PV market is growing dramatically – 43. 64. This is a technology which is seen to have enormous potential and therefore is attracting considerable research effort. As economies of scale also bring down costs. Jubilee Campus. p. Efficiencies of over 40 per cent are confidently predicted. This laboratory has also verified the bench efficiency of 36.5). Heat pumps Heat pumps are an offshoot of refrigeration technology and are capable of providing both heat and cooling. Before these developments had occurred. facades and motorway sound barriers (The Solar Economy. Nottingham University devoted to PV cells producing more than twice the energy demand of the building (Figure 13.9 per cent achieved by Spectrolab’s Improved Triple Junction solar cell. Hermann Scheer calculated that Germany’s aggregate demand of 500 TWh/year could be met by installing PVs on 10 per cent of roofs.4 Photovoltaic cells.ENERGY OPTIONS Figure 13.
Germany certain chemicals absorb heat when they are condensed into a liquid and release heat when they evaporate into a gas. The principle of the GHP is that it does not create heat. In the near future a COP of 6 is likely. air or water. This is another technology which goes back a long way but which is only now realising its potential as a technology for the future.5 PV roof over the Mont Cenis complex. 172 . Herne Sodingen. The heating and cooling capacity of the refrigerant is enhanced by the extraction of warmth or cooling from an external medium – earth. The most efficient is the ground source heat pump (GSHP) which originated in the 1940s. Refrigerants which have an ozone depleting potential are now banned. Currently refrigerants which have virtually zero GWP on release include ammonia which is one of the most prevalent. At present ground coupled heat pumps have a coefficient of performance (COP) between 3 and 4 which means that for every kilowatt of electricity they produce 3 to 4 kilowatts of useful heat. There are several different refrigerants that can be used for space heating and cooling with widely varying global warming potential (GWP). The main benefit of this technology is that it uses up to 50 per cent less electricity than conventional electrical heating or cooling.ARCHITECTURE IN A CLIMATE OF CHANGE Figure 13. It exploits the stable temperature of the earth for both heating and cooling. it transports it from one area to another. The theoretical ultimate COP for heat pumps is 14.
The heat pumps operate mainly at night using off-peak electricity to minimise costs. lake or river as the heat transfer medium. In each case the presence of moving ground water improves performance. which acts as a heat transporter. plus the climate change levy. the system ceases to function. 173 .ENERGY OPTIONS Most ground coupled heat pumps adopt the closed loop system whereby a high density polyethylene pipe filled with a mix of water and antifreeze. At current energy prices the system is more expensive to run than a conventional boiler installation. The only problem is that. The supply pipe is run underground from the building and coiled into circles at least 2 m below the surface. namely the Tolvaddon Energy Park in Cornwall which exploits geothermal energy with 19 heat pumps that pump water around boreholes to a depth of 70 metres. If the energy removed from the ground exceeds the ground’s regeneration capacity. to meet the heating/cooling load of a building. Heat pumps have been compared to rechargeable batteries that are permanently connected to a trickle charger. the horizontal loop is laid at a minimum of 2 m depth. The system has 15 shafts sunk to a depth of 45 m. the circuit can be affected by solar gain or rainfall evaporation. gas prices will probably continue to rise due to security of supply problems. In really cold weather immersion heaters in the storage vessels boost heat output. The stored heat together with internal heat gains and the thermal mass of the building provide space heating for most of the time. Pencoys Primary School in Cornwall is an example of a PFI project by W. GeoScience Ltd). The horizontal type is most common in residential situations where there is usually adequate open space and because it incurs a much lower excavation cost than the alternative. will enable the system to overtake a standard boiler option in economy of running costs in the near future. The system was designed by GeoScience. GeoScience was also involved in the design of one of the first business parks in the UK to exploit this technology. The heat pumps produce water at 45–50 C which is stored in two 700 litre insulated buffer tanks. The system has a coefficient of performance of 4. A secondary circuit serves to provide underfloor heating at about 50 C. This. This project was only made viable because of support from the Regional Development Agency (RDA) for the South West which required that this business park should be a demonstration of heat pump technology. The battery is the ground loop array which has to be large enough.S. However. Usually the lowest cost option is to use water in a pond. together with a matched compressor. so it is essential that demand is matched to the ground capacity (from Dr Robin Curtis. is buried in the ground. The energy trickle comes from the surrounding land which recharges the volume of ground immediately surrounding the loop. even at a 2 m depth. It is laid in a U configuration vertically and a loop horizontally. Atkins which supplements its energy with GS heat pumps. The vertical pipes descend up to a 100 m depth.
6). Energy storage – heating and cooling Sources of natural energy are intermittent. A gas boiler and evaporative (adiabatic) mechanical cooling act as backup to the heat pumps.6).6 Building of the Future.ARCHITECTURE IN A CLIMATE OF CHANGE Figure 13. This is a mixed office and residential development totalling 1000 m2. Primrose Hill. The GS heat pumps utilise four plastic pipe loops connected to the reinforcement steel of the piles. by Richard Paxton Architects (Figure 13. In all it is expected that energy costs compared with conventional heating and cooling will be reduced by about 30 per cent (Figure 13. an economical option is to integrate ground source heat pumps into the foundations as demonstrated by the ‘Building of the Future’. in the Middle Ages. This supplements the heating when necessary but also serves as a night cooling system by dumping heat in summer. London Where buildings require piled foundations. A secondary coil is positioned in the roof and linked to the central manifold. These supply both heating and cooling to the floors depending on the season. tide 174 . PVs on the roof meet most of the electricity needs of the building. London. this is not a new concept since. To obtain continuous flows of energy using such sources therefore requires systems of storage. In addition. As stated earlier.
Heat storage The most straightforward method of storage is by means of a network of pipes carrying solar heated air though a reasonably dense medium such as bricks. the problem of space cooling enters a new dimension. First. off-peak or PV derived electricity may be used as the heating element. Exposed concrete floors have been cited as an efficient storage medium for convective and radiative heat transfer. Second. enough heat can be stored to supplement space heating through the whole of the heating season. Alternatively. off-peak or PV electricity. the building fabric can be a significant energy storage system on the basis of thermal mass. Again the principle is to use spare energy. As indicated earlier. In conjunction with air conditioning. this system can result in a dramatic lowering of the required capacity of the chiller unit. storage can help to flatten the peaks of electricity costs by charging the store with off-peak electricity and using the stored power to reduce demand at peak periods. The storage potential of energy is available for three purposes: heating. hence the term ‘seasonal storage’. A more practicable method is to use phase change and the latent heat of fusion as above to provide high density storage. This system is ideal in situations where there is cyclic demand since it facilitates cooling (or heating) when energy costs are at their lowest or a plant is shut down. to refrigerate a medium. At its crudest.ENERGY OPTIONS mills stored water at high tide in order to release it at an appropriate rate to turn the water wheel during the ebb tide. the medium may be the earth beneath a building. Heat absorbed by the structure flattens the peaks and troughs of temperature. concrete blocks or water. Cool storage As the automatic inclusion of full air conditioning is increasingly being questioned. If sufficient space is available below a building. One option called the STL storage system comprises a storage vessel containing spherical polyethylene nodules filled with a solution of eutectic salts and hydrates. It is worth noting again that it is the 175 . More sophisticated is the use of a phase change material such as sodium sulphate which works on the principle of the latent heat of fusion. cooling and the storage of electricity. The system may be given a lift in efficiency by the use of heat pumps which provide either cooling or warmth on the principle of a refrigerator. Called eutectic or ‘Glaubars’ salts this medium turns from solid to liquid at around 30 C and then gives off heat as it solidifies. surplus solar energy can be used to charge a storage facility to be used later for space heating. The storage container is heavily insulated. Energy storage offers an efficiency and cost gain in two respects. in buildings that optimise solar gain.
Summer Winter Heat Exchanger Heat Exchanger Cold circuit Cold well Warm well 15–20° Aquifer 10°C Aquifer Warm well 176 . Known as ‘aquifer storage’ the principle is that. Figure 13. It is then returned to the warm well. one warm the other cold. in summer.6 per cent overall heat transfer whilst concealing services. The effectiveness of the underside of the floor is negated by suspended ceilings. The system relies on the fact that ground water is a constant (10–12 C in the UK). It loses heat to the building and returns to the cold well at about 8 C to be stored for summer cooling (Figure 13. via a heat exchanger. cools the ventilation system. In winter the system is reversed and warm water heats the ventilation air. This system should be distinguished from the tanked seasonal storage at Frierichshafen described earlier which is fed by solar thermal panels.7).ARCHITECTURE IN A CLIMATE OF CHANGE outer 100 mm of the fabric which comprise the effective thermal mass. In summer water from the cold well is pumped into the building and. As it passes through the building it absorbs heat ending up at around 15–20 C. buildings absorb considerable amounts of surplus heat which can either be vented to the atmosphere or used to provide a reservoir of warmth for the winter. The energy storage system comprises two wells drilled into the water table below the building. Seasonal energy storage A marriage between solar energy and the thermal constancy of the ground offers an opportunity to make significant reductions in both the heating and cooling loads generated by buildings. However. a compromise solution is perforated tiles which have an open area of 42 per cent which is sufficient to allow 91.7 Principles of seasonal storage (courtesy of CADDET) Basic functioning of energy storage in aquifers.
Also there are two 75 m deep boreholes. Aquifers at 40 m depth are used for cooling. Recent buildings to benefit from this technology include the Reichstag in Berlin and the city hall and Schiphol Airport offices in The Hague. expensive and of limited life. completed in September 1999. but the promised breakthrough in this technology has yet to materialise. The Sainsbury supermarket at Greenwhich Peninsular.5 million cubic metres of natural gas equivalent. Figure 13.ENERGY OPTIONS The Netherlands are leading the way in this technology with 19 projects completed or under way with a projected annual primary energy saving of 1. Even the ground-breaking Freiburg zero electric house relied on lead acid batteries for its fall-back position. the other providing ground cooling. employs earth sheltered walls to regulate temperature on the sales floor. In the case of the Reichstag surplus heat is stored interseasonally in a natural aquifer 400 m below ground. one absorbing heat from refrigeration equipment. Still in general use is the traditional lead acid battery which is heavy.8). Ventilation air is passed through underground ducts to maintain cooling. The PV hydrogen fuel cell copes with most of the year (Figure 13. Electricity storage Batteries Battery technology is still the most common method of storage. Lighter but more expensive are nickel–cadmium batteries which have the advantage of rapid charging achieved by low internal resistence.8 Banks of lead acid batteries in the Freiburg Solar House 177 .
This has left people with the feeling that if they do not match the typical occupant profile. Often the environmental data collection and control system is incorporated within an overall building management system (BMS) which also deals with communication networks. P. 258). fire protection. It can be discharged and recharged up to 10 000 times. occupancy related scheduling and a number of other functions. This order of improvement makes it an attractive storage proposition for buildings employing PV generation (Ball. As an indication of its efficiency. the ability of the occupants to influence their own environment has been degraded. of course. The incorporation of computers. serious environmental hazards associated with cadmium. Further difficulties can arise if the facilities manager lacks either the 178 . BMS/BEMS are generally designed to operate to control heating. p. The portion of the system dealing with energy is the building energy management system (BEMS). though the building as a whole has the potential to optimise its energy and environmental performance to achieve some centrally defined goal. One of the most promising batteries is the Ovonic nickel–metal hydride battery. Building management systems Digital control mechanisms and the availability of system controls to operate them have developed rapidly since the 1970s. there is evidence to show that occupants are more tolerant of less than perfect environmental conditions if they have some control over their immediate environment. ventilation and air conditioning systems in terms of engineering the status of the internal environment. Further. There are. Frequently. The location of the control system need not be on-site and the supervision of the system may well be located centrally for multiple building complexes or for a series of similar buildings in outlying areas.ARCHITECTURE IN A CLIMATE OF CHANGE The car industry is particularly interested in this form of storage. security. (1997) Made to Measure. The incorporation of whole building systems control has often been accompanied by centralisation of the decision-making power. lift operation. Princeton. which may in some circumstances operate autonomously. As a result. a lead acid battery could give a vehicle a range of 190 kilometres. lighting. modern multiple-parameter optimisation techniques and intelligent control have enhanced the opportunity to provide very sophisticated environmental control systems in buildings. Poor occupant satisfaction with environmental control systems has also been associated with complaints of sick building syndrome. They can also be used to control more passive features such as window opening and shading device position. the system is under the control of a facilities manager. The Ovonic battery would raise this to 480 kilometres. they have to accept the discomfort.
similar principles have been analysed with reference to commercial developments. are most usually applied within domestic-scale designs. The one which has been adopted as the European Reference Model is the Environmental Systems Performance Model produced by Integrated Environmental Solutions (IES) which can be linked to Autocad. permits a straightforward prediction of likely energy use for lighting. However. does provide a quick guide to energy consumption by indicating optimum window size and orientation at the initial design stage. The perimeter zone is that which is subject to significant external climatic influences on its lighting. Such an approach.ENERGY OPTIONS time or the expertise to understand the complexities of the BMS analyses and thus does not appreciate the subtleties of the system or how the system can be fine tuned to create maximum energy savings. The technique gives annual comparisons and is relatively quick and easy to use. heating and (if specified) cooling services on an annual basis.ies4d. Overcomplexity also affects the occupants who may revert to the option requiring least effort which may also be the least energy efficient. The system is described in Baker. (2000) Energy and Environment in Nondomestic Buildings. The LT Method. Its programs facilitate a full dynamic thermal modelling of a building and consequent energy consumption (APACHE-calc and APACHE-sim). whilst being somewhat simplistic. Control of environmental conditions inside buildings is certainly of crucial importance in reducing energy consumption as well as affecting the well-being and efficiency of the occupants. At the time of writing one of the most sophisticated and comprehensive computer modelling systems also comes from IES (www. A number of variations of this method now exist to deal with a variety of building types. One assessment method that addresses this sector is the Lighting and Thermal Value of Glazing Method – the ‘LT Method’. It is therefore valuable in determining the basic plan form. which has so far been developed for use in the European climate. along with their subdivisions. University of Cambridge. developed in the UK.com). The Martin Centre. This model is perhaps more appropriate at a post-graduate level. The perimeter zones are classified by orientation and depth. For more complex analysis a number of programme suites now exist. negate the benefits of the whole system.V. 179 . This method reduces a building to an orthogonal plan with core and perimeter zones. Tools for environmental design The three main categories of passive solar design. Cambridge Architectural Research Ltd. The combination of inadequate user control or central management can. N. heating and cooling requirements. as mentioned earlier. and are defined as passive zones.
(2000) Energy and Environment in Non-Domestic Buildings.ARCHITECTURE IN A CLIMATE OF CHANGE Earlier. 2050 and 2080 using data from the UK Climate Impacts Programme (UKCIP). Report by Arup Research and Development for the DTI’s Partners in Innovation Programme 2004 Report on offices The datum for the research was the weather in 1989 which was extrapolated to 2020. In the non-domestic sector the benefits of. 180 . Natural ventilation is employed in 70 per cent of UK offices. reference was made to its ‘Suncast’ program which generates shadows from any sun position. project leader for the research). University of Cambridge. The Martin Centre. The report predicts that a 1960s office that is naturally ventilated will be unusable between June and August by 2080 with internal temperatures reaching 39 C. The report makes the sobering remark that even the BRE low energy office in Watford fails to meet BRE’s own benchmark for comfort from 2020 onwards. ‘Air conditioning needs to be combined with passive cooling systems to provide a greener and more cost-effective solution’ (Jake Hacker. N. As a postscript to this chapter it is useful to summarise the conclusions of a report by Arup referred to earlier on building performance in the context of climate change up to 2080. That is 3 degrees hotter than the July average for a street in Cairo. Such mixed mode solutions are the way for the future. It has the advantage that its programs are graded in complexity and so can be introduced at undergraduate level. and problems associated with. Above 28 C occupants experience increasing discomfort. Cambridge Architectural Research Ltd. It suggests that even offices which are air conditioned to current climate extremes will be inadequate. It predicts that temperatures in the south of England could be up to 8 C warmer by 2080 reaching 40 C. The report recommends that air conditioning systems should be driven by renewable electricity – PVs etc.V. solar radiation are summarised in Baker. This raises questions about current recommendations regarding night cooling of offices as the external air temperatures get hotter. The research used a median of four UKCIP climate change scenarios based on progress in abating CO2 emissions.
Principal factors influencing levels of daylight are: ● ● ● ● orientation of windows. It will be some time before we realise the revolution in lighting promised by developments in light emitting diodes. especially since certain forms of artificial lighting have been implicated as the source of health problems. particularly in open plan offices. the use of windows and plan form of buildings was very much influenced by the limits of natural light admission. Furthermore.g. Current wisdom has it that office design should optimise natural lighting. reflectivity of surrounding surfaces. Energy efficient buildings should make as much beneficial use of naturally available light as possible. Factors which relate to the exploitation of daylight include: ● ● ● Windows provide external views and time orientation for occupants. Natural light produces a true colour rendering. There was the added psychological penalty of reducing access to daylight and external views. Lighting is important because of the influence it has over occupant experience. It is only relatively recently that the importance of these benefits have been acknowledged. Until about 50 years ago. 181 . nearby buildings). angle of tilt of windows.Lighting – designing for daylight Chapter Fourteen As one of the largest energy sinks for commercial and industrial buildings. Occupants are more accepting of variable illumination when daylight is the light source. The development of the fluorescent tube lamp made the deep plan office a feasible proposition but at the expense of noise pollution and frequency band discomfort. lighting justifies special treatment. obstructions to light admission (e. One reason for this is that lighting is often the largest single item of energy cost. with buildings becoming increasingly energy efficient in terms of space heating so the lighting load becomes of greater significant. Another factor is that occupants tend to prefer natural light.
Rooflight spacing should be one to one-and-a-half times the ceiling height. m H height of top of window. it would be unusual to expect to supply all lighting requirements using daylight in non-domestic buildings. Allocation of rooms to facades should be appropriate to the activity – to do this successfully will require consideration of the issues at the building planning stage. and Pitts. P. Generally rooflights provide about three times the benefit of an equivalently sized vertical window. 182 . Large windows admit light but also provide heat gain and heat loss routes and thus potential thermal discomfort. Rooflights give a wider and more even distribution of light but also permit heat gains which may cause overheating. Batsford). it may simply increase contrast. A. The amount of sky which can be seen from the interior is a critical factor in determining satisfactory daylighting. Design considerations In order to achieve successful daylighting design. Where single sided daylighting is proposed. Adequate daylight levels can be achieved up to a depth of about 2. External obstructions/buildings which subtend an angle of less than 25 to the horizontal will not usually exclude use of natural daylight.5 times the window head height. m W room width. m Rb average reflectance of internal surfaces (Adrian Pitts in Smith. the following formula gives a limiting depth (L) to the room: (L/W ) (L/H) 2/(1 .C. the following aspects should be considered: ● ● ● ● ● ● ● ● ● ● ● ● ● The amount of glazing has a clear influence on the amount of daylight available. (1997) Concepts in Practice – Energy.ARCHITECTURE IN A CLIMATE OF CHANGE However. High window heads permit higher lighting input as more sky is visible. but more window area is not always better. If there are many external obstructions the room depth should be reduced. Daylight normally penetrates about 4–6 m from the window into the room. especially from cold draughts near the windows.Rb) where L room depth.
Initially Norman Foster opposed the idea of reinstating a dome since this was emblematic of an era best forgotten. Internal reflectances should be kept as high as possible. with the lower portion sealed from the upper space (echoes of Wren at St Paul’s Cathedral). Examples One of the most dramatic techniques for channelling daylight into the deep interior of a building has been devised by Foster Associates for the Reichstag building. The motorised shading and the heat exchange equipment is powered by photovoltaics (Figure 14. the window area should be about 20 per cent of the floor area to provide sufficient light to a depth of about 1.1 Reflective cone in the Reichstag 183 . Sun-tracking shading prevents direct sunlight from reaching the chamber. It is effectively a double dome.LIGHTING – DESIGNING FOR DAYLIGHT ● ● In non-domestic buildings.1). However.. Figure 14.5 times the height of the room. The cone houses air extract and heat exchange equipment. The original design was for an all encompassing canopy but this proved much too expensive.
ARCHITECTURE IN A CLIMATE OF CHANGE The atrium The atrium has become an almost universal feature of commercial buildings. as in the case of the city campus of Sheffield Hallam University (Figure 14. However.2 Atrium between existing buildings. The offices enclosing the atrium will benefit from a measure of natural light as well as external views. ● ● The structure of the atrium roof can reduce its transparency by between 20 and 50 per cent. This is an important factor if the ground level is meant to be predominantly naturally lit. Access to natural light will be improved significantly if the sides of the atrium are stepped outwards. There is no doubt that much of the appeal of atria lies in their aesthetic attributes. Occasionally the incorporation of an atrium can transform existing buildings. The shape and form of the atrium also has an important effect on the availability of natural lighting in the spaces adjacent to the atrium. they have a practical justification by creating opportunities for introducing natural light and ventilation often deep into a building. There are several factors to consider.2). Sheffield Hallam University 184 . Figure 14.
light shelves cannot increase the lighting level. The system is heavily reliant on the availability of sunlight and for critical tasks or areas a backup artificial light source is required. The light is concentrated using lenses or mirrors and is then transmitted to building interiors by ‘pipes’. Some degree of control is possible by modifying the angle of the light shelf. Figure 14. Under conditions of an overcast sky. Light shelves Light shelves have been in use for some time and serve the dual purpose of providing shade and reflected light. but the system can be used as an alternative to the reflective louvre system without some of its drawbacks. Maintenance is virtually eliminated if the system is installed between the panes of double glazed units. Light pipes Light pipes gather incoming sunlight sometimes using a solar tracking system. This almost doubles the daylight levels in north facing rooms.3 Basic principle of the light shelf Prismatic glazing Whilst the systems so far discussed rely on the reflection of light. The pipes can be hollow shafts or ducts with reflective internal finishes. Figure 14. especially the external type. They operate most effectively in sunlight. Portcullis House illustrated this feature with a level of sophistication involving a corrugated reflective surface to maximise high altitude reflection whilst rejecting low altitude short wave solar radiation. or may use fibre optic cable technology. Problems with low angle winter sunlight penetration can give rise to glare. Examples of the technology are to be found in the roof of the concourse at Manchester Airport.4 Section through a sunpipe 185 . The system consists of a panel of linear prisms (triangular wedges) which refract and spread the incoming light to produce a more diffuse distribution.4). Sunlight is reflected from the upper surface of the light shelf into the room interior and particularly onto the ceiling where it provides additional diffuse light thus helping to provide uniform illumination. UK. prismatic glazing operates by refracting incoming light.LIGHTING – DESIGNING FOR DAYLIGHT ● The surface finish in respect of colour and reflectance of the atrium walls will influence the level of daylight reaching the lower floors.3). In this context ceilings are usually designed to be higher than normal for best operation (Figure 14. Difficulties can be experience in cleaning the light shelves. A special luminaire is required to provide distribution of the light within the building. Glare can be somewhat reduced too. Earlier. either internally or externally or in combination. and the experimental low energy house at Nottingham University (Figure 14. The view out is substantially restricted.
5 Solar shading. Wessex Water Divisional Headquarters 186 .ARCHITECTURE IN A CLIMATE OF CHANGE Figure 14.
The Millennium Galleries opened in Sheffield in 2001 have some of the most elaborate solar shading which can be rotated through 90 to achieve levels of solar exclusion up to total internal blackout (Figure 14. More common are external shading devices which are confined to the southerly elevation.6 Variable solar shading. A diffraction process is also used. Millennium Galleries. More recently the Wessex Water building features some of the most complex solar shading devices yet encountered (Figure 14. Figure 14. There are some limitations set by the angle of incoming light to which the holographic pattern is tuned.6). Sheffield 187 .LIGHTING – DESIGNING FOR DAYLIGHT Holographic glazing Holographic glazing is still under development but potentially offers advantages over prismatic glazing. but in this case the light output can be more finely tuned to produce particular internal light patterns. These are featured in Portcullis House.5). Solar shading In considering climate facades solar shading featured as an integral element in the triple glazing.
in turn leading to a reduced cooling load. For example. W. For example. Passive solar studies claim that efficient and well-controlled lighting would reduce energy/carbon dioxide costs by more than any other single item. for example. a build-up of user appraisal has shown that. Even in terms of capital cost alone energy efficiency can make savings. At the same time there is the chance to install fewer switch drops reducing cabling and simplifying fitting-out. work in offices was largely paper based. At the same time.Chapter Lighting – and human Fifteen failings Artificial lighting is a major factor in deciding the quality of the internal environment of offices. In addition. (CO2) emissions accounting in the US. Post-occupancy analysis has thrown some doubt on these assumptions (Bordass. particularly if it is linked to automatic controls. March 2001). For these reasons it is a subject that warrants special attention. it is possible for a single 188 . for up to 30 per cent of total electricity use (Scientific American. high frequency lighting. recent occupancy studies have shown that artificial lights are left on much more than predicted. There is still reluctance to accept any additional capital cost to achieve sustainable design despite the prospect of significant revenue savings. the claimed benefits of maximising natural lighting have turned into clear dis-benefits.. As a result. This lighting strategy could also reduce the contract period with obvious benefits in terms of an earlier occupancy date. in many cases. research and guidance in the past has been simplistic and inadequately focused on the real contexts in which people make decisions. It is also a serious contributor to carbon dioxide. Design studies suggest that considerable energy savings can be made by maximising natural light. good reflecting luminaires and infra-red controls can save money because fewer fittings are required with lower heat production. and this chapter will review some of the most prominent. There are many reasons for this. When the original research into alternatives to the permanently artificially lit office space was carried out. Changes in office design and work routines has caused a reappraisal of the maximisation philosophy. PROBE studies).
but that they will tend to resent expending effort on activities which they regard as the responsibility of management. Open systems measure external incident daylight to dim lights but with no feedback of the actual levels of realised illuminance. to avoid the need to make small-scale adjustments. Blinds can override the controls of both open and closed systems. For example. regardless of external conditions. lights should not go off until the illuminance level is about twice the design level. If lighting controls are not tuned to each individual workstation. As a rule of thumb. and that is what happens when natural light levels fluctuate. Even where lights are zoned according to daylight penetration. The common ‘inertia response’ is to close the blinds and switch on the lights. individuals will adjust the blinds and artificial lighting to avoid discomfort and achieve an even distribution of lighting regardless of energy consumption. Now computers are the universal office tool and excessive daylight can be a severe nuisance due to reflection from VDU screens. it is not uncommon to find occupants closing the blinds to activate the lights. Furthermore.LIGHTING – AND HUMAN FAILINGS decision by an individual to put a whole system into an energy wasting state. these often do not relate to workstations with the result that lights are on all day to compensate. in many cases there are not enough sensors and lighting zones to take account of localised variations in daylight due to orientation or shading. In open plan situations where no individual is responsible. the systems can be either closed or open loop. Photoelectric control Where lights are operated electronically according to natural light levels. it has been found that all lights can be on because one person has drawn the blinds to avoid glare. blinds tend to be left closed if that was their position on the previous day. A lesson which is being gradually learnt is that individuals will always select the least cost option in terms of effort. Complaints at the lack of finesse of such systems can result in management abandoning photoelectric control altogether. Insufficient consideration is given to the fact that anomalous situations are often difficult to correct and it is easier to adopt the ‘inertia solution’. Where daylight results in glare. It is not that people are inherently lazy. 189 . In cellular offices individuals take more responsibility for adjusting their light levels and optimising the relationship between artificial and natural lighting. A closed loop system controls the lighting to top up the daylight to achieve a given minimum acceptable illuminance level. For example. it is often easier to switch on lights than adjust blinds. Where sensors in closed systems are near windows. this can result in greater energy use than in a conventional office.
On a bright day a constantly lit desk would appear gloomy. Local manual override is the preferred answer. In practice it is often difficult to locate sensors to suit occupancy patterns and work requirements especially in open plan offices where workstations may frequently be relocated. as the level of outside light fluctuates. The operation of externally positioned blinds can be frustrated by adverse weather conditions. The adjustment of the sensors is a matter of fine tuning. One common fault is that the positioning of switches and sensors does not take account of the contribution of natural light. but even this technology is not devoid of problems. Occupancy sensors achieve their optimum value in service areas and circulation spaces. There are obvious advantages to light switching which is responsive to a human presence. Alternatively they may be so sensitive that passers-by trigger the switch causing a distraction. The ideal solution is to rely on manual switching for the ‘on’ and automatic switching for the ‘off’. For example. so individuals may wish to vary desktop light levels to minimise contrast. Occupiers sometimes complain that the spontaneous action of the blind is an irritant and represents a denial of individual choice. Recent developments in glass technology referred to earlier in terms of electrochromic glass offer solutions to these problems. One option is to resort to automatic blinds. The result is tall windows to give maximum daylight penetration. they may not be sufficiently sensitive to the movements of people engaged in high concentration tasks. A balance should be struck between optimum safety and the profligate use of energy. especially if it can be controlled on an individual pane basis. In most cases this will mean desks at right angles to the external wall and the VDU viewing axis parallel to the window plane. These are areas which are frequently overlooked yet they can use more energy pro rata than office spaces. However. This carries the attendant risk of glare unless workstations are properly positioned in relation to the window. 190 . Lights tend to stay on regardless of the position of the blinds. Another problem that occurs is that lighting and blinds controls are not co-ordinated. throughout the whole circulation area.ARCHITECTURE IN A CLIMATE OF CHANGE Glare Another rule of thumb which is observed by designers is that ‘if you can’t see the sky the daylight level is inadequate’. This is a particular fault in offices with atria. Dimming control and occupancy sensing Closed loop systems are designed to provide a constant level of desktop illuminance. In some of the worst cases activating lights in an office area can switch on all lights along the exit route and in extreme instances. especially high winds.. There is also the situation that office managers sometimes fail to address the more subtle needs of staff. The answer would be to include a red ‘live’ light in the switch. Remote infra-red switching is an efficient and effortless system. It may be that system interfaces are not well understood by staff. in one instance. Good communication between management and staff can achieve a satisfactory performance from a less than perfect system. Even service managers and suppliers are occasionally not as well informed as they should be. overcomplex systems discourage interference and adjustment in case the outcome is worse and defies a remedy. Also. cost and energy implications of the system. This is another instance where the complications and cost of modifying the system to respond to new work practices may 191 . gearing the system to crude averages with the result that nobody is satisfied. The human factor is of prime importance. In extreme cases this has led to the complete abandonment of the system. they will tend to operate it at or near its optimum on the principle that overkill masks lower order problems and safeguards one’s back. Light controls may have been designed for fixed working hours and set lunch times. In some cases the fault for poor system performance lies with office managers who fail to inform the staff of the operational characteristics. The problem is exacerbated if the original software source is no longer available. System complexity is another problem. System management One major reason why certain high profile energy efficient buildings fail to meet expectations is because of deficiencies at the level of system management. If services managers are not conversant with the intricacies of a system. The increasing popularity of flexible working hours is causing difficulties. Switches remote from fittings lead to uncertainty as to the status of the lights. Where switching is not ergonomically appropriate the tendency once again is for lights to be left on permanently. staff were not told of the fact that pressing a switch twice would turn on extra lights.LIGHTING – AND HUMAN FAILINGS Switches A common failing is that switches are not positioned logically in terms of their relation to the fittings and behaviour patterns of occupants. For example. Inadequate communication can undermine the virtues of the best possible system design. Complex systems can also be inflexible.
Air conditioned offices These present a different set of problems for designers.30 were obliged to leave the lights burning all night. 192 .ARCHITECTURE IN A CLIMATE OF CHANGE be unacceptable and therefore the system is abandoned. Since staff became able to work flexible hours. As a result. the facades feature solar tinted glass. the inhabitants tend to regard it as natural that all the services should be fully used all the time. They have intelligible local controls with clear user interfaces. There is responsive and intelligent office and services management. The architect and services designer may produce an elegant energy-efficient concept which can be totally vitiated by the fitting-out contractor who has not been informed of the energy saving features and consequent operational constraints of the design. The problem of discontinuity between design intention and fitting-out can be particularly acute in the case of refurbishments. it meant that those working after 17. The psychological effect of a space hermetically sealed from the outside world is to suggest an environment designed to overcome nature and be wholly distinct from it.30 hours. If. Even worse is the situation where the subcontractor deliberately ignores the design objectives of the architect and engineer in order to keep down costs. A relatively recent trend in the production of buildings is for the design to be separated from the fitting-out. even more lighting is used to compensate for the constantly gloomy outlook. There has been a case where all lights in an office were operated from a central control desk. The system is robust and reliable. in addition. Variable working patterns and conflicting needs often means that lights are left on unnecessarily. It is usual for the principal tenant to have overall control of the services. Another potential source of conflict between design and operation is when a single occupancy office reverts to multiple occupancy. Lighting – conditions for success Open plan installations which offer occupant satisfaction and energy efficiency usually satisfy four conditions: ● ● ● ● The design is straightforward and comprehensible. avoiding overcomplexity.00 to 17. It is still comparatively rare to encounter an open plan office which achieves low lighting energy consumption combined with high daylight use and which produces a high level of occupant satisfaction. The desk only operated from 09.
193 . ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● There is an assertive client who has formulated the system’s requirements clearly and insisted from the outset on effective lighting controls. Control systems are capable of responding to individual requirements with good switching design (often infra-red) and controls which are user friendly and take account both of daylight levels and workstation layout. splayed reveals and deeply recessed windows. Interior fittings and furnishings are light in colour and tonal value with tall fittings kept to a minimum. Circulation lighting is low energy and well planned and controlled with full account taken of contributions from daylight. Summary of design considerations ● ● ● Design of artificial lighting systems should not be extravagant. Task lighting should be used for specific workstations in order to reduce the level of general background lighting. overhangs. The system has a high degree of inherent flexibility so that it can be finely tuned and retuned to user needs. lighting levels should be designed be to as low as is permitted whilst still achieving the standard required. Design luminance should be set to achieve about 400 lux with lower levels in circulation areas. There should be efficient lighting throughout with high frequency control gear and good optics. is the occasional external view. It is an advantage to have variety in lighting but without excessive contrast or the ‘oppressive feel’ generated by installations with 100 per cent Category 1 luminaires. Glare is reduced to a minimum by means of light shelves. compact fluorescent lamps should be specified where appropriate. Following commissioning there is intelligent management of the system combined with responsive management at office level. VDUs can be easily moved to avoid glare. An important added advantage in corridors etc.LIGHTING – AND HUMAN FAILINGS Those that achieve low lighting energy consumption tend to display the following characteristics. The interior layouts position most desks at right angles to windows. Energy efficient lamps should be specified – usually high frequency fluorescent or alternative discharge lamps. Daylight within circulation spaces has the effect of putting a brake on the use of artificial lighting in the office areas. There will be good levels of daylight in perimeter work areas without causing excessive glare in interior spaces. Blinds will be easy to operate with a good range of adjustment and which need to be fully closed only in exceptional circumstances.
of all the factors under the designer’s control. Leaving aside the moral arguments. Four types of control are available. for example high frequency electronic ballasts are up to 20 per cent more efficient than the norm. Lights near windows should be separately controlled. Occupancy linked control ● ● ● Sensors (ultrasonic. this can produce savings in spaces regularly used by more than two people. Control gear (ballasts) required for lamp functioning should be energy efficient. infra-red. Gives individual control to occupants. lighting is probably the most powerful influence on mood and demeanour. lights switched off if presence no longer detected. Daylight linked control ● ● ● Can be used in conjunction with timed and occupancy linked systems. 194 . The on/off controlled switching of lighting systems needs careful consideration for optimum performance. giving energy efficient light distribution. Localised switching ● ● ● Allows partial illumination of large areas when not fully occupied. with lights switched on manually. Photocells are installed to detect when natural light is sufficient at which point artificial lighting is switched off. Timed control ● ● Used to switch lights off automatically according to a specified schedule. Switching on is for a set period. quality and means of control are critical factors in determining the well-being of the occupants of a building. This type is particularly appropriate for spaces with low occupancy levels. should be chosen. Recent developments include use of dimming control to avoid abrupt change as lights are switched off. microwave or acoustic) are used to detect presence of occupants. It makes direct contact with the emotions. this can have a direct effect on the bottom line.ARCHITECTURE IN A CLIMATE OF CHANGE ● ● Appropriate luminaires. To conclude. Some form of override switching off required when building becomes unoccupied. As such its disposition.
These ‘Probe’ studies brought to light a number of problems which caused some buildings to perform well below their design prediction. A factor which is often overlooked is that energy is comparatively cheap and accounts for only 1–2 per cent of total occupancy costs including salaries. the picture changes when energy costs are related to profits where they can range from 10 to 20 per cent of the total. A mere 1 per cent increase in productivity paid for a typical company’s annual energy bill. In a specific example. their architect persuaded them to invest in an extra 4 per cent to benefit from energy efficient design. Many professionals are reluctant to negotiate new design territory for fear of falling victim to untried 195 . Where an environmentally effective building really does score is in the sphere of staff well-being. a joint examination by the US Department of Energy and the Rocky Mountain Institute of a number of refurbished offices found that renovations involving lighting and ventilation led to significant increases in productivity. it is necessary to temper enthusiasm with a cautionary note. However. sometimes by a margin of 25 per cent. The result was that absenteeism dropped 15 per cent as against their previous headquarters. It must be said. The Chartered Institute of Building Services Engineers commissioned a number of post-occupancy studies of buildings designed to achieve a high level of environmental sophistication. Not all the fault lies with clients. however. Energy savings were worth $500 000 per year. Why do things go wrong? There is evidence that many recent offices designed to be energy efficient are not performing as well as expected. This means that there is not the incentive to incur extra expenditure to modify systems to meet the original performance specification. For example. the US report states that when Lockheed commissioned a new 60 000 m2 office complex. These are some of the outcomes of the study. that this is in the context of relatively low energy prices.Cautionary notes Chapter Sixteen Having outlined techniques for optimising natural resources in the operation of offices.
Leaving computers switched on unnecessarily not only wastes energy directly. it also adds to the cooling load of the building. In many instances. Even the professionals have problems in this respect though here there is useful guidance in the document ‘Energy Use in Offices’ 2003’ published under the Energy Efficiency Best Practice Programme (now called ‘Action Energy’). They are less likely to embrace low energy design which involves excluding engineering hardware. In extreme cases the system is abandoned altogether. other factors become more energy significant such as duct sizes and fan motors. All construction professionals operate in the shadow of ‘professional indemnity’ which tends to make them overcautious and not ask questions after completion. Lights are another source of concern which will be considered in more detail later. Overcomplex systems which require elaborate maintenance tend to deteriorate fairly rapidly because service managers are not up to the demands of the technology. attention has tended to focus on insulation standards and heating/cooling installations. Avoiding the technological fix and installing only essential technology that is efficient. substantial improvements to energy efficiency can be achieved by paying sufficient attention to the low profile details of design (Bordass. In a cut-throat world. Whilst design professionals are urged to work as a team. Furthermore. The ‘high-tech demand’ Some designers are seduced by the imagery of advanced technology and install hardware that greatly exceeds the real demands of the building and its occupants. a fee structure which is based on contract or subcontract cost operates as a disincentive to services engineers. fan motors are substantially oversized leading to significant excess energy costs. Operating against integrated design procedures is fee competition which sometimes reduces returns for design work to less than cost. should be the aim of designers. the costs of which would enhance their fees. One problem facing clients is the relative scarcity of information which is accessible to the non-specialist.. 196 . Now that Building Regulations are driving up insulation standards. this is often difficult in practice. PROBE studies). designers across all disciplines are more often competitors than collaborators. not overcomplex. In many. cases. A consequence of this is that services designers are often brought into the project at a late stage.ARCHITECTURE IN A CLIMATE OF CHANGE technology or because they will not make the effort to learn new construction techniques. if not most. easy to use and maintain. W. High profile/low profile In the drive to reduce energy consumption.
It may be less of a financial risk to commission the system properly after practical completion. Recent studies have suggested that sick building syndrome is also related to job satisfaction. This problem seems to be especially acute in terms of services technology. Poorly designed heating and ventilation systems have also been identified as culprits. in small-scale buildings. it is not unusual to find an entire heating plant being run in summer to supply hot tap water. An elaborate and expensive chiller 197 . There have been numerous horror stories of badly maintained systems providing a comfortable habitat for all manner of unmentionable life forms as well as closed systems recycling bacteria and viruses resulting in high levels of absenteeism. Another problem which is all too common is that installers are expected to be able to comply with almost impossibly short completion dates. who find it impossible to empathise with the uninitiated installer and operator. If the system goes into operation at a substandard level of efficiency due to time constraints. more accurately termed ‘building-induced sickness’. Commissioning is hurried to avoid activating penalty clauses in the contract. service managers and office staff are at a disadvantage from the start. They cannot conceive the breadth of the knowledge gap. Factors like off-gassing from plastics in furnishings and fittings or the frequency of fluorescent lights have been implicated. Building related illness Over recent years there has been awareness of the phenomenon ‘sick building syndrome’. There is a universal problem with instruction manuals because they are written by experts on the system in question. Job satisfaction is more easily achieved in a pleasant comfortable environment in which the occupants are permitted some degree of control over their surroundings. Unreasonable overcapacity is another problem. the extra effort necessary to fine tune comfort to an individual’s personal preferences quickly pays off. When energy efficient design sets a good baseline of environmental conditions. This is a recipe for high energy consumption and less than perfect comfort conditions. Inherent inefficiencies A system designed to be energy efficient can be totally undermined if the whole system has to be operated to meet a small demand.CAUTIONARY NOTES Operational difficulties It is unfortunately the case that guidance/instruction manuals are often poorly written and inadequate in terms of information. For example. aside from the most spectacular problem of Legionnaires disease.
Sophisticated controls and electronic management systems combined with zonal submetering will ensure that faults are pinpointed and system inefficiencies identified. The scale of such inefficiencies may go unnoticed because of the absence of proper monitoring systems. Maximisation of daylight can produce problems for VDU operators. The relatively small capital costs involved in such equipment will quickly be paid back. Common architectural problems ● ● ● ● ● Adverse effects of too much glass being underestimated. 198 . Often a catastrophic failure is the first indication that something is wrong. lighting and distribution of services. Poor controls and user interfaces. Lower energy consumption is probable when air conditioning is not installed.ARCHITECTURE IN A CLIMATE OF CHANGE may be installed to meet the cooling demand of a few days in the year or to supply cool air to a small number of prestigious rooms. leads to a lower cost per m2 it may be that there are fewer ‘usable’ m2 across the site as a whole due to problems of the distribution of cooling and ventilation. Avoiding air conditioning – the issues ● ● Whilst the avoidance of air conditioning. Inappropriate window design lacking refinement and ease of control. Downside risks not given the same weight as upside visions. efficiency. Optimised engineering solutions which may not be robust and flexible. Fitting-out which may contradict original design intentions. A blind faith in technology tends to underrate the human factor and fails to focus down to the finely tuned needs of occupiers. but not always easy to quantify. Special problems occur with night ventilation. leading to poor performance. Common engineering problems ● ● ● ● Adoption of inappropriate standards regarding climate control. System efficiency can drop dramatically without the management being aware of the problem. and thus reduction of plant. The operation of such systems must be supplemented by adequate supervisory and analytical input from knowledgeable staff. Mechanical ventilation inappropriately designed in terms of rate of ventilation. operating hours and zoning. Tendency to highlight the positive and play down the negative.
The human factor ● ● People are more tolerant of conditions in a naturally run building than in sealed air conditioned boxes. There is less risk in overdesigning than underdesigning. Designers can place too much faith in arrows showing expected air flow when natural ventilation is used – a rigorous approach to patterns of expected air movement is necessary. Accordingly systems are often overpowered and therefore wasteful. 199 . The alternative of a balanced natural/mechanical system requires sophisticated design techniques which may pose too much of a challenge to system designers. This can create variable climate conditions at any given time. There is less plant to maintain without air conditioning. Robust. The drive towards green design has sometimes led to the use of untried and inadequately researched alternatives to air conditioning. and the level of occupant satisfaction is difficult to measure on a constant basis. Common failures leading to energy waste ● ● ● ● ● Designers tend to err on the side of caution. The reasons are that people like to feel in control. hence the need to avoid excessive automatic control and also that they make unconscious adjustments for longer in environments that are congenial. for example the acceptable range of temperature is wider and perceptible air movement more acceptable. clearly articulated systems are the answer. but what there is may be more complex because of modes of operation. Naturally ventilated buildings are claimed to offer greater occupant satisfaction.CAUTIONARY NOTES ● ● ● ● ● ● ● Lower running costs for the building when avoiding air conditioning may be at the expense of staff satisfaction. Small demands like domestic hot water can require whole systems to be in operation as stated earlier. Often the most convenient operating strategy is for switches to default to on whereas manual on and automatic off is the more energy efficient provided safety is not compromised. Inadequate monitoring systems can fail to identify progressive failure. Intrinsic faults in the system may remain hidden but may nevertheless adversely affect energy use without any detectable effect on service. Natural ventilation is less controllable. Natural ventilation is claimed to be more adaptable but it is not always appreciated how this adaptability can be achieved. Occupants generally do not have the patience to keep fine tuning their building environment and will tend to do what is most convenient.
windows etc. The passive potential of buildings should be fully exploited with care taken to ensure that building form. Sudden changes are disrupting therefore automatic climate modifications should occur imperceptibly where this is possible. Conclusions A number of factors are now tending to direct designers away from fully automated systems. automatic off should be the norm. Where natural and mechanical systems are designed to work in a symbiotic relationship it is necessary to ensure that. These are: ● ● Preferred conditions in offices are now complex and unpredictable. 200 . again. In such instances it is often perceived as easier to decommission the system than rectify it. Most of the time external views are perceived at a nonconscious level. controls. Monitoring is essential to determine running costs and to identify critical failure paths before they lead to catastrophic failure.ARCHITECTURE IN A CLIMATE OF CHANGE ● ● ● As a general rule people find it easier to switch systems on than off. Awareness of the outside world is an important component of contentment. Overcomplex systems can generate unpredicted consequences and even episodes of total failure. So often averaging out was another term for a ‘lowest common denominator’ solution. Too often there is still no clear analysis of what controls can really achieve and how proficient people will be at operating and servicing them. but psychological studies indicate that the mind can make a very full response to the visual milieu without reference to consciousness. making it impossible to design for average needs. hence. blinds. manual on. building design. climate sensitive. designers and modellers are still reluctant to abandon their faith in fully automated controls. the inertia factor tends to increase when people are in groups. Even so. in changeover conditions. ventilation. Mixed mode ventilation and cooling systems with different services zoned according to use patterns and need are often the most suitable strategy. the system does not default into concurrent operation of the mechanical and natural systems. are all supportive of natural systems. At the same time. Summary of recommendations ● ● ● ● The temptation to opt for complex and ‘heavy’ engineering should be resisted in favour of ‘gentle engineering’ in which loads on the HVAC (heating. There is a reluctance to be conspicuous with its potential for risking criticism. ventilating and air conditioning) system are kept to a minimum by appropriate.
201 . energy wasteful options. robust systems which are well within the abilities of both service and office managers to understand and users to operate. This will deflect occupants from resorting to easy.CAUTIONARY NOTES ● ● Changes in office routine and design have revealed that opting for maximum daylight can produce irritating consequences. such as glare on VDU screens. To repeat: the objective should be to design straightforward. Furthermore. consistent with operational realism. maximum daylight designs rely on the reliability and user friendliness of blinds and this reliance has often been misplaced. This is the recipe for sustainable design. The aim of the design team should be to achieve maximum energy conservation.
Chapter Life-cycle assessment and Seventeen recycling Waste disposal ‘The Earth is infinitely bountiful’. increasing pressure on land for waste disposal. so say the eco-sceptics. This provides the context for considering the problems of waste. Pakistan.25 years which means the natural capital account is going increasingly ‘into the red’ (Mathis Wackernagel at a conference ‘Redefining Progress’. Packaging and style upgrades exploit the human drive to be seen to be in the height of fashion. At the same time we may be placing a valuable recyclable resource beyond use.7 years for the annual biological harvest to regenerate. Far from it. In 1962 it took 0. 1. In ecological terms this means that the Earth is already living beyond its means. Worldwide the average is 4. Land is Earth’s most valuable commodity which is being increasingly diminished by building development and landfill sites. 20 February 2003). For example. the ecological footprint is the area of land (and sea) taken up to meet the needs of individuals or societies. The reality is that society cannot continue to consume natural assets at the current rate. in turn. There is a temptation to think that when waste is thrown away. in the UK the average per capita is 14 acres. A citizen of the US uses 34 acres. As the natural capital of the Earth is being steadily eroded this is increasingly an ethical as well as an economic problem.6 acres. pollution arising from landfill disposal. Currently it takes 1. that’s the end of it.5 acres due mainly to consumption in the industrialised nations. From being our problem it becomes someone else’s. February 2003 reported in The Guardian. The market economy encourages ever more vigorous consumerism which. energy involved in disposal. increases the rate of obsolescence. More and 202 . The irony is that our most expensive artefact after a house is the car which is designed for increasingly longer life. The waste being generated by the increasing consumerist ethos of the industrialised nations imposes four penalties: ● ● ● ● depletion of natural resources.
These dictate a nation’s standing in relation to other countries. merely transformation. e-mail debi@handr. Nations measure their success by the level of per capita GDP and the extent of annual economic growth. Plans are being considered to levy a charge for each bin collection from a home. reconstituted materials. It is in the sphere of building that recycling has considerable potential. refurbished materials.uk/ salvage_home. This is what recycling is mainly about. composting organic kitchen waste and most garden waste (some plants are not suitable for composting). and this applies to renovation as well as new build. There are at least three aspects to this: ● ● ● reused items for the same or an alternative purpose. Reuse Building demolition provides an endless source of items which can be reused with almost no adaptation. There may be an added incentive to reduce the amounts of household waste. Local councils are under growing pressure to collect waste in segregated bins to facilitate recycling. The solution starts in the home. Some councils offer composting bins at a discount. delivering to appropriate waste bins.co. At the same time householders can do a great deal to help the process along by: ● ● ● reusing items wherever possible. Recycling We are slowly moving to a position where there will be no such thing as waste.html. separating waste at source and. This index was started 203 . This should be a major issue in local elections.co. notably plastic bags and containers.uk). constant style changes and technological tinkering rather than functional efficiency are needed to keep the market buoyant. Architectural salvage has become a significant industry. where there are not segregated collection facilities. So. not least within highly influential bodies like the International Monetary Fund and World Bank.handr.
Reconstituted materials In refurbishment schemes it is likely that there will be some element requiring the use of concrete. By agreement with the manufacturers all off-cuts were kept in separate containers taking care to keep them clean and then returned to the manufacturers to be recycled into new plasterboard. The Index covers: ● ● ● ● building materials: bricks.salvoweb. flagstones and other heavy items. Radiators. plasterboard. complete structures: barns. are obvious candidates.com/ dealers/v-and-v/index. metals. If this is not feasible local markets may well find a use for them. This figure can be reduced to 100 kg/m3 by the introduction of ground granulated blast furnace slag (GGBS) to provide additional bulk. Normal concrete uses about 323 kg/m3 of cement. relatively recent buildings are being demolished to make way for more intensive and lucrative site development. though not in the case of multi-storey buildings. It was estimated that 20 per cent of plasterboard comprises waste off-cuts. windows. conservatories and pergolas. flooring. aggregates. stairs. stone and timber. internal features: panelling. The only drawback is that the curing time is increased from the normal 28 days to 56 days. pumps etc.ARCHITECTURE IN A CLIMATE OF CHANGE in 1977 to recycle building materials and architectural features from buildings that are being demolished or renovated. The first requirement in minimising waste is to segregate materials – timber. In many situations this may not be a problem. Refurbished materials As the pace of economic change accelerates. external features: a range of garden features and furniture. doors and central heating items. This means that many items are being dismantled long before they should be retired offering good opportunities for refurbishment. The construction industry is the sector which carries the most guilt in this respect with its voracious appetite for raw materials and its resistance to cutting waste. slates. This has led to mounting pressure to employ recycled materials. 204 . as illustrated by the Earth Centre case study below.html for reclaimed bricks.com/dealers/ n1architectural for architectural features and www. This is normally an energy intensive material due to the mining of aggregate and the production of cement. An example of good practice is the case of Dartford Hospital. This can reduce the cement content by 70 per cent in mass concrete for bases etc. There is also N1 Architectural Salvage at www. tiles. fireplaces.salvoweb. hard plastics – to be recycled on site where possible.
It is based on Howard. Details of this system may be found on at www. building-in-use and disposal stages of a product’s life-cycle. Whole life costing This focuses on the financial profile of a building and its market cost. Clearly some of the categories have a greater overall impact than others. In 1998 the Building Research Establishment (BRE) developed a scoring system for environmental impacts known as Ecopoints. and Anderson. In translucent form it can be backlit as illuminated flooring or walling. (1999) Methodology for Environmental Profiles of Construction Materials. J. In parallel with this there is also growing awareness of the value of calculating the economic cost of a building from inception to demolition.uk/envest. Components and Buildings. it is available in a wide variety of colours and textures. There is therefore a system of weighting which reflects these differences. It covers some of the same ground as life-cycle costing but excludes the 205 .co. (See Crystal Paving Ltd of Ecclesfield Sheffield.uk. The outcome is a system of Ecopoints and the higher the score the greater the environmental impact. water pollution and raw materials extraction. To avoid the charge of subjectivity the BRE consulted with a wide range of construction professionals and environmentalists before fixing on a system of weightings. These various environmental impacts are then assessed against 13 categories including climate change. manufacture.) The mountains of waste slate in North Wales are slowly being ground into powder form to be transformed into resin-based building materials which can receive a high polish. Crushed and mixed with resin. Waste glass has found a new incarnation as decorative tiles and blocks. N. atmospheric pollution. Tel.co.bre. web address:. As wall tiles they have the appearance of polished granite at a fraction of the cost.uk.LIFE-CYCLE ASSESSMENT AND RECYCLING The upgrading of the railways has resulted in a good supply of timber railway sleepers – an excellent source of recycled timber that can be put to a range of uses. e-mail info@crystalpaving. S. processing. 0870 770 6189. like climate change. particularly in gardens.co. The benchmark is the environmental impact caused over a year by the average UK citizen which is set at 100. Life-cycle assessment Pressure is mounting to derive standards for environmental performance over the lifetime of a building by targeting the environmental impact of its component materials. transport. BRE.. It is an ideal cladding material. Edwards. The system deals with the extraction.
Cement is formed by heating clay and lime in a rotary kiln to a temperature of about 1450 C which produces some 3000 kg per tonne of carbon dioxide (CO2).uk. It can take conventional cements centuries or even millennia to absorb as much as eco-cements can absorb in months’ 206 . yet this is the destiny of buildings according to John Harrison. concrete attracts criticism from environmentalists on account of its carbon intensive production techniques and its use of a once-only natural resource. and concrete gains few points on the sustainability scale. The ultimate eco-credential of this material is the rate of carbon sequestration.wlcf. The roasting process produces CO2 but most of this is reabsorbed by a process of carbonation as the cement hardens. The important point is that it marks a move from pure capital costing to integrating capital and revenue costs into an overall whole life cost. the impacts caused by mining etc. a technologist from Hobart. buildings as carbon sinks is another. Eco-materials Concrete As possibly the most extensively used building material. Add to this the carbon miles in transportation. He has produced a magnesium carbonatebased ‘eco-cement’.org). Geopolymerisation is a geosynthesis which is a reaction that chemically bonds minerals to form molecules that are structurally comparable to the molecules which provide the strength to rocks. The market availability of this material is said to be at least five years away (see www. Tasmania. In the first place it only uses half the energy for process heating required by calcium carbonate (Portland) cement. Whole life costing information may be found on www. In addition the heating process produces a chemical reaction through the conversion of calcium carbonate into calcium oxide which releases about 2200 kg of CO2. limestone. Saving energy is one thing.geopolymer.ARCHITECTURE IN A CLIMATE OF CHANGE production process. This is said to be due to the avoidance of calcination from calcium carbonate and the lower kiln temperature of 750 C. Using eco-cement for such items as concrete blocks means that nearly all the material will eventually carbonate resulting in an absorption rate of 0.. The development of the technology of geopolymers offers the prospect of a more eco-friendly concrete.org.
These particles absorb ultra-violet radiation and they use this energy convert NOx into nitric acid which is either washed away by rain or neutralised by the calcium carbonate particles. plastics. Most of the solvents used come into the category of volatile organic compounds (VOCs) and are aggressive pollutants. E. (2000) Ecology of Building Materials. Vermont. There is one further attribute to this material. UK) claim that a coating of the paint will continue to be effective for five years in a heavily polluted city. Oxford). Harrison estimates that a shift to eco-cement could ultimately cut CO2 emissions by over 1 billion tonnes since it could replace 80 per cent of uses currently served by Portland cement. The manufacturers (Millennium Chemicals of Grimsby. It has been calculated that over 500 000 tonnes of solvent are released into the atmosphere globally each year (Harland. Eco-cement is not unique in its pollution absorbing properties. sawdust. USA. External finishes A similar principle has been incorporated into a paint that is now available. Paints Paints have three constituents: pigment for colour. This means that an eco-concrete tower block can perform the same function as growing trees as it steadily fixes carbon.LIFE-CYCLE ASSESSMENT AND RECYCLING (‘Green Foundations’. 13 July 2002. Called ‘Ecopaint’ it is designed to reduce levels of NOx in the atmosphere. New Scientist. In Japan 50 towns are already using these photocatalytic cements and in Hong Kong it is estimated that they remove up to 90 per cent of the nitrogen oxides or NOx gases that create smog. revised edition). Being less alkaline than Portland cement it can incorporate up to four times more waste in the mix than conventional cement to provide bulk without losing strength. 40). Magnesium-based concrete coated with titanium dioxide could be the basis for eco-cities of the future. It is the solvents which are the main problem since they are designed to evaporate. (1999) Eco-Renovation. rubber and fly ash. B. This could include organic waste which would otherwise be burnt or added to landfill. Architectural Press. p. Another statistic is that organic solvents are responsible for 20 per cent of the hydrocarbon pollution in the atmosphere and second only to motor vehicles (Berge. a binding substance to hold the particles of pigment together and a solvent to enable the mixture to flow freely. 207 . The paint contains nanoparticles of titanium dioxide and calcium carbonate. Mitsubishi is producing paving slabs coated with titanium dioxide which remove most pollutants from the air. Chelsea Green Publishing Company.
405 and also Edwards.net. Temperature is the key factor in determining how much moisture the air can hold. Materials and embodied energy In addition to the energy used during the occupied life of a building there is also a significant energy factor in terms of the materials used in its construction.. the transfer of moisture will not happen if wall surfaces have impermeable finishes like oil-based paints or varnishes. In other words. plastic wallpaper or even wallpaper fixed with plastic-based pastes. at 0 C it can only hold 3. L.8 g/m3. When the water vapour enters the hygroscopic materials these chemicals may be deposited and broken down giving these materials a degree of air cleansing capacity. the processing of the raw material into finished products. pp. Rodale Press. This ensures that excess moisture can be absorbed by the plaster and masonry wall. are as easy to apply.ARCHITECTURE IN A CLIMATE OF CHANGE It is the solvents which derive from the petrochemical industry that are the most toxic and are implicated in the phenomenon of off-gasing. are solvent free. 251–253).) There are alternatives such as those containing natural resin emulsions. A further benefit is that water vapour carries some gas contaminants like nitrogen oxide and formaldehydes. (A comprehensive list of surface treatments and their solvents is to be found in Berge. p.. hygroscopic materials have a damping effect on moisture fluctuations just as thermal mass regulates temperature (Berge. Humidity The choice of paints and varnishes can have an impact on the level of humidity within a building. Such materials act as a stabilising agent. do not have the pervasive smell of chemically based paints and are also biodegradable. 208 . However. releasing it when the internal humidity level creates imbalance. It is important that the materials of the walls can absorb much of this moisture which means the use of hygroscopic materials. ibid. that is. It falls into five divisions: ● ● the extraction from the earth of raw materials.aecb. ibid. They appear much the same as conventional petrochemical emulsions. It is recommended that internal walls should be finished in hygroscopic emulsion paint over plaster. At 20 C air can hold 14. This may continue for a considerable time with sometimes serious health consequences. keeping the humidity level reasonably constant. Fluctuations in temperature will alter the carrying capacity of the air and may result in condensation. materials that can take up moisture. J. available from the AECB book service: g/m3. and Lawless. otherwise condensation is virtually inevitable. Internal walls need to breathe. (2003) The Natural Paint Book. On average a living room contains 5–10 g/m3.
Heat is stored over the summer to be circulated throughout the winter. the demolition and recycling of materials. for example. the energy used in the processes may be withheld for commercial reasons. At this stage in the development of disclosure about embodied energy. Solar collectors on the roof direct warm water to a calorifier in an underground insulated 400 m3 tank.LIFE-CYCLE ASSESSMENT AND RECYCLING ● ● ● the transportation to the supplier and then to the site. since it is a renewable resource with the added benefit of fixing CO2 during growth. Earth Centre. Doncaster This is a building built to the highest super-insulation standards which is no less than we would expect from its architect. extraction and processing. their lifetime would be extended. Energy inputs into metals such as copper and aluminium can vary according to whether the source is from ore or recycled material. Assuming an average life for an office building in the UK of 15–20 years. Bill Dunster. sourcing materials as near as possible to the construction site. if buildings were to be made more adaptable. There are strong environmental reasons to use timber in construction. and thereby more accommodating to numerous changes of work pattern. with the first two stages. However. In the UK. The situation is further complicated when some of that energy is from renewable sources. the present replacement rate of housing means that life expectancy of a home is around 2000 years. However. For example. thus reducing the overall percentage attributable to embodied energy. in the UK most softwood is imported. as buildings become more energy efficient. A case study will illustrate a whole building approach to recycled materials. as in the case of aluminium processed in Canada from hydroelectric power. with a wood burning 209 . the most direct impact can be made on ‘carbon miles’. making the embodied energy an insignificant element. Low energy Conference Centre. It has natural wind-driven ventilation with heat recovery from exhaust air transferred to incoming air. about 7 per cent of total energy consumption is embodied in materials. or bricks in Nottinghamshire fired by landfill methane. so the reverse is true and ultimately the embodied energy may become the prime factor. the construction process. The matter will only be resolved when disclosure becomes a legal requirement. On the other hand. The problem with embodied energy is that it is difficult to quantify with any confidence. adding a significant transport component.
The Conference Centre walls are of gabion construction. that is. loose stones contained with a galvanised steel mesh.1).ARCHITECTURE IN A CLIMATE OF CHANGE stove for backup heat. under construction and completed 210 . Figure 17. In this case the filling comprises crushed concrete from a nearby demolished colliery.1 Conference Centre. A wind generator mounted in the boiler flue helps to meet the electricity demand (Figure 17. Earth Centre.
considerations about embodied energy and resource depletion should be factored in.salvo. This is an important precondition of a project. Reference to best practice case studies is useful in this respect. Even the wet heating system uses radiators recovered from demolished buildings and the steel for the conical roof to the conference space is recycled I beams. The entrance steps are redundant railway sleepers (a growth industry). On the supply site. Earth Centre. discovered in a lorry park. Buildings which can be dismantled rather than demolished are much better in this respect. (p. A useful website is www. despite its very high embodied energy. Only the Gluelam beams are from new timber in order to meet the manufacturer’s performance guarantee. retailers of recycled materials should provide a measure of quality assurance if not a full guarantee.uk. Design practices need to adapt to accommodate the recycling culture. Contractors should be persuaded to be co-operative about the use of recycled materials and willing to accept a degree of liability on behalf of subcontractors. subcontractors may be reluctant to work with them because of hidden hazards like nails in timber which can wreck valuable tools. In the Earth Centre example the contractor was able to underwrite extra costs arising from work on recycled materials. 211 .co. For example. All these items should contribute to a favourable life-cycle assessment score. A main contractor may also experience difficulty in guaranteeing time and quality on a design and build fixed price contract. Sadly in 2005 the Earth Centre closed. Recycling strategy checklist ● ● ● ● ● ● First a client should be encouraged to sanction the use of recycled materials. At the same time designers should maximise the opportunities for materials to be recycled after demolition. There are problems associated with recycled materials. Most of the timber is either recycled or has received a certificate from the Forestry Stewardship Council.LIFE-CYCLE ASSESSMENT AND RECYCLING The timber supports for the main structure are rejuvenated pylons. All site waste should be sorted and recycled where possible. It is impossible to avoid using cement. In the case of the Conference Centre. Where possible GGBS concrete has been used in foundations etc. At the same time there should be considerable overall savings as against new materials which should have an impact on the whole life cost assessment. In determining costs. the main contractor was an enthusiastic advocate of the strategy. 204). probably telegraph poles. This can save the costs of transport and landfill fees.
It also has to last 100 years. When completed it should prove to be one of the most accessible and user-friendly parliamentary buildings of any state or principality in Europe. The engineers are confident that the building will use no more than 50 per cent of the energy of a building conforming Regulations in this location. The curved member on the top of the cowl has an aerofoil profile creating negative pressure on the underside thus assisting the extraction of exhaust air (Figure 18. 212 .. It is a classic example of architect and engineer working in concert from the earliest stage of the project. so the primary aim was to drive down operational energy demand. The results of extensive modelling of solar penetration and daylight at different times of day and at all seasons of the year have been factored into the design. Airflow over and around the building has been modelled using computational fluid dynamics (CFD).Chapter State of the art case Eighteen studies The National Assembly for Wales Richard Rogers Partnership Following devolution. The design brief was for a building which reflected the democratic nature of government whilst also being a landmark example of low energy design. The rotating roof cowls ensure that the grilles for exhaust air are always in the lee of the wind which is predominantly from the south west. the Principality of Wales was granted greater autonomy resulting in the need for an assembly building for which the Richard Rogers Partnership was appointed architects with environmental engineer BDSP. and rises through the debating and reception chambers through the stack effect. Ventilation air enters at low level since there is little low level pollution. Given this lifespan.1).
Beddington Zero Energy Development (BedZED) Bill Dunster Architects BedZED is not just another low energy housing scheme. 218 . well laid out.ARCHITECTURE IN A CLIMATE OF CHANGE Figure 18. The Commission for Architecture and the Built Environment described the project as ‘one of the more sustainable schemes to be built anywhere in England because it sharply addresses energy efficiency and life maintenance cost.6).6 Lillie Road flats. affordable accommodation’ (Building for Life Gold Standard) (Figure 18. courtyard view (photograph by Mandy Reynolds) It is the first social housing project in the UK to incorporate these three off-site fabrication techniques in one scheme. combined with a range of generously proportioned.7). it is a prescription for a social revolution. a prototype of how we should live in the twenty-first century if we are to enjoy a sustainable future (Figure 18.
Excluding the sports ground and placing cars beneath the ‘village square’ the density could be raised to 105 homes and 200 workspaces per hectare.7 BedZED west elevation The design was led by Bill Dunster Architects who are one of the UK’s top evangelists for ecologically sustainable architecture with the services and energy strategy developed by Arup Associates. organic shop and health centre. maisonettes and town houses. Peabody was able to countenance the additional costs of the environmental provisions on the basis of the income from the offices as well as the homes. studios.STATE OF THE ART CASE STUDIES Figure 18. radically cutting down on the demand for travel. 2500 m2 of space for offices. This density includes the provision of 4000 m2 of green space including sports facilities. The housing comprises a mix of one. In every respect this is an integrated and environmentally advanced project. At such a density almost 3 million homes could be provided on brownfield sites with the additional benefit of workspaces for the occupants.and two-bedroom flats. shops and community facilities including a nursery. It consists of 82 homes with 271 habitable rooms. workspaces. It is a high density development along the line recommended by the Rogers Urban Task Force. 219 . it had to stack up in financial terms. all constructed on the site of a former sewage works – the ultimate brownfield site. Though the Trust is extremely sympathetic to the aims of the scheme. The Innovative Peabody Trust commissioned this development as an ultra-low energy mixed use scheme for the London Borough of Sutton. It realises an overall density of 50 dwellings per hectare plus 120 workspaces per hectare.
These standards of insulation are a considerable improvement over those required by Part L of the 2002 Building Regulations in the UK.8 North elevation with workspaces at ground level and roof gardens serving dwellings opposite 220 . Masonry external and internal walls and concrete floors provide substantial thermal mass sustaining warmth in winter and preventing overheating in summer.ARCHITECTURE IN A CLIMATE OF CHANGE Some dwellings have ground level gardens whilst the roofs of the north facing workspaces serve as gardens for the adjacent homes (Figure 18.20. Roofs also contain 300 mm of insulation. The majority of all the materials were sourced within a 35 mile radius.10. External walls consist of concrete block inner leaf.10. In the case of BedZED great attention has been paid to maximising air tightness which is designed to achieve two air changes per hour at 50 pascals (2ac50P). One of its primary aims was to make the most of recycled materials and the main success in this respect was to obtain high grade steel from a demolished building as well as timber.8). The energy efficiency of the construction matches anything in the UK or mainland Europe. They are framed in timber and have a U-value of 1.9). In traditional construction up to 40 per cent of warmth is lost through air leakage. Materials containing volatile organic compounds (VOCs) have been avoided as part of the strategy to use low allergy materials. Floors contain 300 mm of expanded polystyrene also having a U-value of 0. Figure 18.11 W/m2K (Figure 18. 300 mm of Rockwool insulation and an outer skin of brick adding up to a U-value of 0. in this case Styrofoam with a U-value of 0. Windows are triple glazed with Low-E glass and argon filled.
On average.STATE OF THE ART CASE STUDIES Figure 18. BedZED aims to reduce domestic water consumption by 33 per cent.11).9 Masonry wall construction Ventilation becomes an important issue as better levels of air tightness are achieved. This is to be achieved by the use of water-saving toilets. The heat recovery element captures up to 70 per cent of the heat from the exhaust air. According to the 1998 version of SAP ratings BedZED achieves 150. regulations now stipulate a 7. In this case the design team opted for passive natural ventilation with heat recovery driven by roof cowls.5 litre dual flush toilets are provided producing an estimated saving of 55 000 litres per household per year. Taps are fitted with flow restrictors. Overall energy demand should be reduced by 60 per cent. A vane mounted on the cowls ensures that they rotate so that incoming air always faces upwind with exhaust air downwind. It is predicted that space heating costs will be reduced by 90 per cent against a SAP 75 building. Until the 2002 revision of the Regulations dwellings were required to achieve around SAP 75. Here 3.10 and 18. 18 per cent of a household’s water 221 . Sunspaces embracing two floors on the south elevation add to the quality of the accommodation (Figures 18. dishwashers and washing machines. As the scheme uses metered water it is expected that these measures will save a household £48 per year.5 litre maximum. showers that rely on gravity replace baths in single bedroom flats. The energy efficiency drive does not end there. Toilets normally use 9 litres per flush. South facing elevations capitalise on solar gain with windows and their frames accounting for nearly 100 per cent of the wall area..11 South elevation with PVs integrated into the glazing 222 .
Across London 51 000 tonnes of tree surgery waste is available for gasification. It is worth restating that this is virtually a carbon neutral route to energy since carbon taken up in growth is returned to the atmosphere. In the future rapid rotation willow coppicing from the adjacent ecology park will supplement the supply of woodland waste. The waste would otherwise go to landfill.11 illustrates the inclusion of PVs in the south glazed elevations of the scheme. It is fuelled by a mixture of hydrogen.12). Originally the idea was to use PVs to provide for the electricity needs of the buildings. Foulwater is treated in a sewage treatment plant housed in a greenhouse. This is sufficient for the power needs of the scheme. taking into account their high taxation burden. So. Evacuated tube solar collectors would provide the heating. There is a further chapter to the energy story. Their purpose is to provide a battery charging facility for electric vehicles. The output from the plant is of a standard equivalent to rainwater and therefore can supplement the stored rainwater to be used to flush toilets. If the electricity were to be used to displace the use of fossil fuels in vehicles. It is predicted that the scheme will be a net exporter to the grid (see Chapter 8) (Figure 18. Figure 18. How the decision was made to dedicate the PVs to this role is worth recording. They are also sited on southerly facing roofs. The energy package The principal energy source for the development is a combined heat and power unit which generates 130 kW of electric power. it was calculated that 777 m2 of high efficiency monocrystalline PVs would provide a peak output of 109 kW. It turned out that this arrangement would involve a 70 year payback timescale. It is a biologically based system which uses nutrients in sewage sludge as food for plants.STATE OF THE ART CASE STUDIES requirements will be met by rainwater stored in large tanks integrated into the foundations. Excess electricity is sold to the grid whilst any shortfall in demand is met by the grid’s green tariff electricity. sufficient for the energy needs of 40 light 223 . The plant requires 1100 tonnes per year which translates to two lorry loads per week. The CHP plant is reckoned to be of adequate output due to the high standard of insulation and air tightness and the fact that the peaks and troughs of seasonal and diurnal temperature are flattened by the high thermal mass. The plant also meets its space heating and domestic hot water requirements via a district heating system served by insulated pipes. the payback time would be about 13 years. carbon monoxide and methane produced by the on-site gasification of wood chips which are the waste product from nearby managed woodlands. Household waste normally destined for landfill will be reduced by 80 per cent compared with the average home. A combustion engine generates the heat and power producing 350 000 kWh of electricity per year.
Other car pool schemes have indicated that hiring a pool car to cover up to 13 000 km a year could save around £1500 in motoring costs. The aim is that the 40 vehicles would provide a pool of cars to be hired by the hour by residents and commercial tenants.12 Wood chip gasification plant within the development (courtesy of ARUP and BRE) CHARCOAL DRYING ENGINE HEAT HEAT electric vehicles covering 8500 km per year. On-site work and recreational facilities together with the electric vehicle pool of ‘Zedcars’ would more than satisfy that commitment. Peabody is one of the most enlightened housing associations in Britain. Bill Dunster was engaged on the strength of Hope House which he designed as an ecologically sound living/working environment and which served as a prototype for BedZED. The idea came from Bioregional Development Group. The co-developers Peabody and Bioregional agreed as part of the terms of the planning consent to enter into a Green Travel Plan which meant a commitment to minimise the residents’ environmental impact from travel. This development has come about because the right people were able to come together in the right place at the right time. With congestion charges due to be levied on vehicles using streets in other major cities besides London. a family car travelling 12 000 miles (19 000 km) per year produces almost as much carbon dioxide (CO2) as a family of four living in a typical modern home. It has to be remembered that. And that is without factoring in the potential avoided cost of pollution. A diagram produced by Arup summarises the ecological inventory of the project (Figure 18.ARCHITECTURE IN A CLIMATE OF CHANGE BIO-FUELLED CHP GRID FLUE M WOOD-GAS MULTI-STAGE CLEANING GASIFIER WOODCHIP CHP ENGINE IMPORT/EXPORT METER ELECTRICITY AUTO-DISCONNECT UNIT ALTERNATOR Figure 18.13). the energy used by a conventional car could greatly exceed that used in the dwelling. the exemption of electric vehicles will provide an even greater incentive to adopt this technology. in a project like BedZED. an environmental organisation based in Sutton who secured Peabody as the developer. Chris Twinn of Ove Arup and Partners worked 224 . As a yardstick.
published by BRECSU at BRE e-mail address: brecsuenq@bre. In future. refer to ‘General Information Report 89’. The project happened due to a fortuitous conjunction of people committed to the principles of sustainable development.uk Figure 18. BedZED – Beddington Zero Energy Development.13 The ecological inventory of BedZED (courtesy of ARUP and BRE) Beaufort court renewable energy centre zero emissions building Studio E Architects Where possible the reuse of existing buildings is the best way to meet the sustainability agenda.co. developments of this nature must not rely on the chance collision of the brightest stars in the environmental firmament. Sutton. For a more detailed description of this project. An excellent example of this strategy is the headquarters of an energy company near London. The description of the development by David Lloyd Jones of Studio E Architects is quoted 225 .
the space heating and the associated mechanical and electrical systems (Figure 18. modern. Design principles The Renewable Energy Centre is the first commercially developed building to be carbon neutral and entirely self-sufficient in energy. particularly in respect to energy supply and use. a range of renewable energy measures and employing ‘best practice’ sustainable strategies. Indeed the various integrated renewable energy systems will. This will be fed into the electricity grid for the use of the community. have now been converted and extended to provide for the office and visitors’ centre accommodation. This funding was conditional on the adoption of a radically innovative approach to resolving sustainable issues and the involvement of a pan-European design and development team. A sustainable approach was taken. Studio E Architects The Renewable Energy Centre at Kings Langley in the UK is the new headquarters and visitors’ centre for Renewable Energy Systems Ltd.14). a seasonal heat store. generate a surplus.ARCHITECTURE IN A CLIMATE OF CHANGE at length as being the most appropriate explanation of the design strategy. The original buildings on the site housed chickens to provide eggs for the nearby Ovaltine malt drink plant. over any year. The project brief was the conversion and extension of the former Ovaltine egg farm to provide 2665 m2 of headquarters office accommodation for RES. This was to be carried out using. idiom reflecting the contemporary concerns of Renewable Energy Systems and the leading edge energy technologies deployed over the site and concealed within the buildings. The design was based on the comprehensive application of passive and active solar measures and is believed to be the first commercial net zero carbon dioxide emissions building in the UK. weather and internal comfort are being monitored over a 2 year period. On the basis of this innovative content. RES requested that additional facilities for visitors and parties 226 . derelict for 10 years. RES was assisted in this objective by the contribution from the EC Framework 5 Programme. The editions and replacements are expressed in a clean. No attempt was made to replicate the arts and crafts style of the original buildings in the new building works. Solar design aspects of the renewable energy centre and interim findings David Lloyd Jones. An EC Framework 5 grant contributed to the cost of a hybrid PV thermal array. a company whose business is developing wind farms on a global basis. These buildings. The project was completed in December 2003 and the energy systems. so far as economically practical. albeit sympathetic.
e. d.14 Energy strategy who might wish to see and learn about the building and its energy systems. provide exhibition. o. the design principles upon which the development is based were to: ● ● provide a fully operational head office which meets the commercial needs and conditions of the property market. j. air handling installations Fresh air Exhaust air Irrigation Figure 18. m.. 227 . l. c. g. b. Accordingly. i. n.STATE OF THE ART CASE STUDIES a. k. conference and facilities for the use of RES and visitors to the building. f.
aligns with the Ovaltine factory – the destination of all the eggs laid on the old farm. conference. The conversion of the horseshoe was more complex. by a private road. meeting. by the mainline London to Glasgow railway. and main plant spaces. The layout of the various elements comprising the development is shown on the site plan. the two wings of the horseshoe. The energy strategy It is intended that all energy used at the Renewable Energy Centre be provided by renewable sources located on the site. Both the ‘coach house’ and ‘horseshoe’ buildings had to be converted for modern office use with. and the outer external wall rebuilt. exhibition. The construction between the two towers. in addition. the ground floor was lowered. The conversion of the coach house was relatively straightforward: the building fabric was upgraded to meet contemporary office use and the courtyard was enclosed by inserting a new steel structure. if extended northwards. technical and aesthetic aspects of the project. integrate seamlessly the social. the existing buildings had to be radically altered and extended. Turf was planted on the roof of the new office space. was placed between. However. deliver a building whose energy consumption is provided entirely from on-site renewable energy sources. The boundary of the site is formed. The egg farm is set out on an axis. and connecting. Its location adjacent to one of Europe’s busiest motorways brings sustainability in action closer to the millions of people using the road.ARCHITECTURE IN A CLIMATE OF CHANGE ● ● ● deliver a building that minimises energy consumption and the use of scarce resources and that contributes positively to local economic and community needs. A third entirely new building was introduced close to the northern perimeter of the site.5 ha of farmland located in the metropolitan green belt. was entirely demolished. The ground floor was extended into the courtyard by 5 m and a new single-storey link. the local planning authority required that the views of the outside of the building must remain largely unchanged. to the north east. The project demonstrates 228 . incorporating the main entrance. except for the timber roof structure. The new buildings In order to provide for the new uses. Its roof comprises the hybrid photovoltaic/thermal array. This building provides storage for the harvested biomass crop. this building was partly sunk into the ground and the excavated earth banked up against the north wall. to the west. and. catering. The site layout The triangular site comprises 7. which. So as not to intrude in the landscape. to the south. by the M25 orbital motorway. the upper level floor and the roof reinforced.
requires the building to be artificially cooled in summer months. building management systems) and passive systems (solar heating. harvested annually. recycled materials. the heat of which is passed to: – a seasonal heat store. artificial cooling. The construction work was undertaken on the basis of minimising waste and using materials and components with low embodied energy from readily available resources. materials that derive from the minimum use of energy in their manufacture and transport (low embodied energy materials). a hybrid photovoltaic/thermal (PVT) array providing both electricity and hot water installed as the roof to a biomass crop store.STATE OF THE ART CASE STUDIES the integration of passive solar techniques with a range of inter-related renewable energy systems. The energy provision derives from: ● ● ● ● ● optimising the use of natural ventilation. solar control. This strategy avoids the heavy energy consumption and potential polluting effects of refrigeration 229 . This. the outward facing facades had to be sealed. dried and stored in the earth-sheltered space beneath the PVT array. use of resources and improving the amenity of the area. together with the relatively high levels of heat generated by modern office use. future biomass plant which shreds the miscanthus and burns it to provide heating for the building (and. natural ventilation and lighting. in a forthcoming adaptation. low air infiltration. low use of water.15). car sharing and the encouragement of the use of public transport. In order to minimise the need for energy. To cut out the disturbance from noise inside the buildings. solar shading. ground water cooling pumped from an 80 m deep bore hole to cool the buildings in summer (and then passed out of the building to irrigate the biomass crop). The cooling source is water drawn from aquifers located in the chalk below the building. daylight. heating and lighting. – a biomass crop (miscanthus or ‘elephant grass’) cultivated on the surrounding land. with the PVT installation. possibly. a well-insulated building envelope incorporating thermal mass) was developed. the minimisation of resource depletion. all the electrical power required by the building and a significant surplus fed into the national grid. used to assist heating of the buildings in winter (Figure 18. Clean and green Bringing back to life a derelict building rather than building new is a considerable benefit in terms of land utilisation. a 225 kW wind turbine supplying. high insulation. a judicious combination of active systems (mechanical ventilation. The buildings are exposed to considerable external noise from passing trains to the west and the motorway to the south. comprising a 1100 m2 body of water concealed beneath the ground. combined heat and power (CHP)).
or sheltered from.15 PVT/heat store/space heating FRESH AIR BUILDING plant normally used for air conditioning. cooling the air within it. Electricity is generated from the PVT array and the wind turbine. to ventilate the building in 230 . Heat is supplied from the biomass boiler (or gas boiler until such time the biomass plant is installed) and from the PVT array. Hot water from these sources is used in a similar way as the chilled water for cooling. the motorway and the railway. either direct or via the seasonal ground heat store. The cool water is used to drop the temperature of air being fed into the building and/or is circulated through convectors within the office space. Windows can be opened in facades and roofs facing away.ARCHITECTURE IN A CLIMATE OF CHANGE DRAIN BACK TANK COMBINED PV + SOLAR THERMAL ARRAY HEAT EXCHANGER HEAT STORE EXHAUST AIR Figure 18.
The building is well insulated and sealed. Wildlife is encouraged by the re-creation of natural habitats. including opening and closing the roof lights. In addition there is a car park and a 5 aside football pitch.7 MWh 133. About 5 ha of the 7. It also records all monitored results from the various energy systems before passing the results to a site in Denmark for uploading onto the website. The remainder of the land is planted with indigenous species of trees. 231 . and excess power (equivalent to the needs of around 40 homes) will be exported to the grid. The turbine is connected to the buildings’ electrical distribution network and to the national grid. shrubs and grasses. Space heating 85 MWh 15 MWh 24 MWh 12 MWh 160 MWh 115 MWh 3. The renewable energy sources Wind Turbine The 225 kW wind turbine has a hub height of 36 m and a rotor diameter of 29 m and is a Vestas V29 model previously in operation in the Netherlands. Predicted energy use and energy supply is shown in the table below.2 MWh* 4. RES actively encourages staff to use public transport.7 MWh 187 MWh 102 MWh A building management system (BMS) controls and optimises all the energy systems. which is greater than the anticipated building consumption. bicycles and car sharing for travel between home and office.5 ha site are given over to miscanthus cultivation..STATE OF THE ART CASE STUDIES temperate conditions. It is expected to generate 250 MWh annually.5 MWh 250 MWh 248. The current monitoring programme will show whether these predictions are borne out in reality. thereby reducing unwanted solar gains and the need for cooling.
First. The field is expected to yield 60 oven-dried-tonnes per year with a calorific value of 17 GJ/tonne. The bales are shredded before being fed into the biomass boiler. PVT array The 170 m2 solar array comprises 54 m2 of hybrid PV/thermal (PVT) panels and 116 m2 of solar thermal panels. The 100 kW biomass boiler is provided by Talbott’s heating. and a copper Water In 3mm Toughened Glass Photovoltalc Cells Absorber Sheets DE Electrical Cable to Inventers Insulation Heat Transfer Pipework Figure 18. Water is extracted from the local aquifer at 12 C via a 75 m deep borehole. which converts light into electricity. Finally.ARCHITECTURE IN A CLIMATE OF CHANGE Biomass The buildings’ heating needs will primarily be met by a biomass boiler fuelled by the energy crop: miscanthus or ‘elephant grass’. The boiler is expected to be installed and operating in 2004–2005. Ground water cooling Ground water is used to cool the buildings during the summer. which is coppiced on short rotation.16 PV/thermal panels (Courtesy of Studio E Architects) Water Out Aluminium Glazing System 232 . The shredded bales are fed into the boiler by a mechanical screw auger.. It is 80 to 85 per cent efficient and can modulate down to 25 per cent of full load. The crop is harvested annually in the late winter with conventional harvesting equipment and stored as bales until needed. it is used to cool and dehumidify the incoming air to the buildings in the air handling units. the water is used to irrigate the energy crop. The emissions from the boiler comply with the Clean Air Act. 5 hectares of which have been planted on the site.
The solar thermal panels are identical to the PVT panels.17 General views of Beaufort Court View from Southwest PVT array Heat stone prior to lid being installed 233 .16).STATE OF THE ART CASE STUDIES heat exchanger on the back to capture the remaining solar energy. They produce electricity and hot water (Figure 18. incorporating Shell Solar PV elements and Zen Solar thermal elements. The panels have been developed by ECN in the Netherlands. Seasonal underground heat store The underground heat store is an 1100 m3 body of water that stores the heat generated by the PVT and solar thermal panels for use in the buildings during the colder months. The top of the store is insulated Figure 18. but without the photovoltaic element.
The relatively low-grade heat from the store can be used to preheat the incoming air to the building. increasing the capacity of the store. The sloping sides are uninsulated. so the heat generated by the PVT array will be stored in the heat store. Beaufort Court with a floating lid of 500 mm expanded polystyrene. and heat will be extracted from the heat store to heat the incoming air to the building. Some heat will also be lost to the surroundings. It is hinged around the perimeter to allow for the expansion and contraction of the water and the design also incorporates a suspension system to support the roof should the water level reduce. In the autumn some of the solar heat generated will be used directly in the buildings and the excess will be added to the heat store. During the winter the solar heat generated will be less than the buildings’ heat load. The high specific heat capacity of water (4.18 Forecourt. as the outside air will be at a lower temperature than the water. This is estimated to be about 50 per cent of the total heat put into the store over the summer. During the summer there will be little or no demand for heat in the building. As long as the ground around the store is kept dry. 234 . it will act as an insulator and additional thermal mass. The temperature of the water in the store will gradually rise over the summer and early autumn. The temperature of the water in the store will drop as the heat is extracted.2 kJ/kg C) makes it a good choice for storing heat.ARCHITECTURE IN A CLIMATE OF CHANGE Figure 18.
each of 50 000 litres. two thirds of the roofs are covered by black coated stainless steel solar collectors. energy efficiency subsidies and the greater use of renewable energy sources. First. the solar panels supply hot water to two storage tanks per block. The driving force behind the scheme was the proposal for legislation to reduce the use of non-renewable energy by means of a carbon tax. They supply domestic hot water in summer and supplement space heating during spring and autumn. In winter fresh air entering the ventilation system in the apartments first passes through the grid warming the air by up to 10 C due to the fact that the earth temperature never falls below 10 C. They would comprise clusters of new communities which would create the ideal opportunity to realise the goal of integrated environmental design at the district level. In anticipation of these measures this community constructed a major housing development consisting of nine apartment blocks which took the exploitation of solar radiation to the limit of current technology. a solar city near Geneva. Cambridge. In summer the system is reversed to provide space cooling. The extract air is pumped into the car park thus avoiding the need for additional ventilation. The project was completed in 1996. Peterborough. City of Anglia and City of Mercia. This comprises a 6 km grid of pipes under the car park. Second. For example. mostly in the Southeast of England. Third. in the UK there is a projected need for nearly 4 million new homes. The fourth attribute of the scheme is the ‘earth source preheater’. One suggestion by the planner Peter Hall is that there could be three new cities around London which he calls City of Kent. These will focus on existing towns and cities: Ashford.Integrated district environmental design Chapter Nineteen Demographic changes are creating a demand for new communities in developed countries. One project that has gone some way down this route is in Switzerland at Plan-les-Ouates. These are about 30 per cent less efficient than the most advanced glazed solar panels but they are significantly cheaper and can rapidly be installed to form an integral part of the roof system. Wellingborough and Rugby. the project employs a double flow ventilation system which provides all apartments with one to two air changes per hour with full heat recovery. 235 .
The purpose of the project is to demonstrate that solar housing can be viable in high density urban situations. wind.1) under the direction of Professor Klas Tham. The performance of the houses will be monitored by a new method of measuring carbon dioxide output devised by energy expert Norbert Kaiser. Linz City Council envisages that this will ultimately be a new town accommodating 30 000 people. comprising a whole new district consisting of housing. integrate appropriate technologies like solar.ARCHITECTURE IN A CLIMATE OF CHANGE In Austria. A canal. They will also power a heat pump which will extract heat from underground aquifers and the sea to meet about 83 per cent of district heating requirements. It is being built on a reclaimed industrial site by the Ribersborg beach and close to the historic centre of Malmo. terraced and apartment dwellings. promenade. The district will include 800 homes in a mixture of detached. Energy strategy A 2 MW wind turbine and 120 m2 of PV cells connected to the grid will account for the area’s electricity demand. Sweden A European Commission demonstration project is almost completed in Malmo. The first phase of building will consist of 600 social housing units built to strict energy conservation standards and designed by some of Europe’s leading architects. The objectives of the scheme are to: ● ● ● ● meet 100 per cent of energy needs from renewable sources by providing innovative energy generation plant and distribution systems. offices and other services. Malmo. shops. The same aquifer system will store cold water to provide cooling in summer. parks and covered walkways are incorporated into the development. with its 11 GWh/year energy demand making no net contribution to carbon dioxide (CO2) emissions. heat pumps and aquifer storage to produce cost-effective clean heat and electricity. It aims to be a zero net energy scheme. Ecological City of Tomorrow. services designers and builders from inception to completion. About 15 per cent of the remaining heat demand will be met by 236 . It formed the centrepiece of an exhibition ‘Bo01’ held in June 2001 (Figure 19. The project is the first phase of a 10 year programme to make the city of Malmo a model of sustainable regeneration. harbour. establish synergy between Malmo’s existing electricity and district heating system and the local system. engage in holistic design procedures involving architects. the European Commission is sponsoring the Linz Solar City.
Biogas produced from local waste will meet the remaining 2 per cent of heat requirement. It is worth noting that the Swedes tend to regard 22 C as a minimum level for comfort compared with 18–20 C in the UK.INTEGRATED DISTRICT ENVIRONMENTAL DESIGN Figure 19. At this rate it should be possible for the inhabitants to maintain the comfort standards to which they have become accustomed. Occupants will have the opportunity 237 . The aim is to keep energy consumption in buildings below 105 kWh/m2 per year.1 Model of the ‘City of Tomorrow’ and the integrated energy system 2000 m2 solar collectors.
keeping space heating demand to a minimum. barring catastrophes like sea level rise. Cities have powerful symbolic resonance which means that there are considerable constraints on change. There is also a plant which extracts energy and nutrients from the sludge from a sewage works. All the buildings are designed to the highest energy efficiency standards.ARCHITECTURE IN A CLIMATE OF CHANGE to adjust and monitor their energy consumption with the help of IT. hence the zero net energy label. Towards the less unsustainable city The ultimate challenge will be to transform existing towns and cities so that they become less of an ‘ecological black hole’. Over the next 50 years. Over the year there should be a balance between the district’s electricity production and consumption. A biogas digester treats organic waste from the district converting it to fertiliser and producing biogas for heating and vehicle fuel. Transport is a key factor in any sustainability policy. the project is assured of security of supply of electricity. The public transport system will be adapted accordingly and the pool of cars within the development will include electric and gas powered vehicles. By connecting the renewable generators to Malmo’s existing distribution system. A ‘vacuum refuse chute’ extracts organic waste from household refuse. All residents receive up-to-date information about waste separation and disposal. Information technology is used not only to regulate the different elements of the energy system but also to inform residents about their energy consumption and allow them a degree of control over their energy management and comfort. All households will be connected to a broadband network equipping them for advanced communication functions such as voice activated systems as well as monitoring management systems. The city is an epicentre of consumption. It is planned to embark on a programme of vehicles powered by environmentally friendly fuels. Completed at the end of 2001 it forms an appropriate gateway to Sweden situated as it is at the end of the spectacular Oresund bridge and tunnel complex linking the country with Denmark. From there it goes to the biogas digester. There will be charging points for electric vehicles and a station providing natural gas for vehicles. The target is to reduce unsorted waste by 80 per cent. The management vehicles will be electrically powered. but also capable of being the highest visible manifestation of civilisation – ‘civis’ the city. The design of buildings and energy systems is integrated under a single management strategy with the whole process being subject to stringent quality control. Disposal hatches attached to each property lead to holding tanks from which the waste makes its way to two docking stations at the edge of the site. the basic form and infrastructure of European cities will not change all 238 .
waste. Energy services It is in this sphere that the local council has been particularly far sighted by recognising that energy has both immediate social and long-term global implications. business and residential customers. But the most important priority is for towns and cities to make drastic reductions in their demand for fossil-based energy and in this respect there is a borough in the UK heading in the right direction. drastically reduce CO2 emissions. the reconstruction process in most cases followed the routes of the original infrastructure. The company has entered into an agreement with the borough to act as its contractor to provide combined heat and power to the borough.INTEGRATED DISTRICT ENVIRONMENTAL DESIGN that much. management of natural habitats. It can claim to have one of the most environmentally progressive local administrations in the UK which has committed the authority to eight key themes under the headings: ● ● ● ● ● ● ● ● energy services. transport. Its purpose is to build. In 1999 Thameswey Energy Limited was formed in partnership with a Danish energy service company (ESCO) International ApS. Individual buildings will be replaced or radically upgraded and the economics of the process will depend on uncertainties like the value of land and the price of energy. on the other. procurement. As suggested at the beginning energy prices as likely to rise steeply as demand increasingly outstrips supply. planning and regulation. Woking: a pace-setting local authority Woking is south east of London close to the M25 motorway with a population of over 89 000. Even after the 1940s blitz which destroyed the heart of many great cities like Liverpool. On the one hand it seeks to eliminate fuel poverty and. The first project was a CHP station supplying heat and chilled water services by private pipes and electricity by private grid to the 239 . adapting to climate change. In order to implement its energy strategy a council-owned company was formed called Thameswey Limited to act as an Energy and Environmental Services Company. education and promotion. As much as anything this was because of services routes and the complexities of land ownership. They have subscribed to the Royal Commission on Environmental Pollution’s targets of a 60 per cent reduction in emissions by 2050 and an 80 per cent by 2100. finance and operate CHP stations of up to 5 MW capacity throughout the town and offer energy services to institutional.
The most innovative enterprise by Thameswey Energy is the Woking Park project. There is also provision to direct surplus electricity to sheltered housing accommodation (Figure 19.3). These together with heat fired absorption cooling and a thermal store add up to a CHP capacity of 1. an ‘extra care’ sheltered housing scheme. The park complex includes a 200 kWe fuel cell. In order to sidestep the problems of supplying small amounts of PV electricity to the grid at an uneconomic rate. Brockhill. the council has created a mini-distribution system of private wires enabling it to sell PV and CHP electricity direct to customers. The CHP stations achieve 80–90 per cent Figure 19.195 MWe. The fuel cell is of the phosphoric acid type which uses hydrogen reformed from natural gas. with surplus heat in summer used to generate absorption cooling and dehumidification.11 pkW PV installation. It was officially commissioned in 2001 (Figure 19. In all 117 sheltered housing tenants receive PV electricity. including Prior’s Croft.4).2 Combined heat.2). together with plans to include an 836 kWe CHP reciprocating gas powered engine. was the first in the UK to use a combination of CHP and PVs to serve its energy needs. The extensive use of photovoltaics also features in the borough’s strategy. This development is also served by a small CHP unit producing 22 kWe and 50 kW of heat backed up by a 6 50 kW boiler  . It supports the heating and power needs of the pool in the park and leisure centre.ARCHITECTURE IN A CLIMATE OF CHANGE principal energy users in the town centre including the council offices. cooling and power grid. two 75 kWe CHP engines and 9.
Woking Park efficiency compared with coal fired power stations at 25–35 per cent. location. the new use should represent an 80 per cent reduction in CO2 emissions. Planning and regulation The main concerns are: ● ● ● ● ● land use.INTEGRATED DISTRICT ENVIRONMENTAL DESIGN Figure 19.3 Phosphoric acid 200 KWe fuel cell. This is because of the utilisation of heat from the engine and compact grids with minimum distribution losses. As regards location. The aim is that. the council operates a measure called Public Transport Accessibility Level Rating (PTAL). ranging from 1 to 7 with 7 being the most proximate to public transport. It is estimated that such measures reduce energy use by 20 per cent. landscape. 241 . when land use is changed. The concept of ‘environmental footprint’ is a prime consideration in land use policy. layout. Planning policy promotes housing layouts which maximise passive solar design and a preference for terrace housing and flats which minimise heat loss through external walls. New development proposals are assessed according to where they feature on the scale. This is particularly concerned with the CO2 emissions that are generated by the current use of the land. Most new development in the borough scores near the top of the scale. sustainable construction.
ARCHITECTURE IN A CLIMATE OF CHANGE Figure 19.4 Prior’s Croft PVs and inverters to convert DC power from the PVs to AC electricity 242 .
by 2010–11. The council has the most energy efficient public housing stock in the UK with an average NHER rating of 8. Energy use in buildings is targeted by encouraging insulation standards above those required by the Building Regulations. Transport Council promotional campaigns seek to raise awareness of the benefits of alternative fuel vehicles at the same time encouraging local filling stations to provide liquid petroleum gas (LPG). The anaerobic digestion of organic waste provides gas for CHP engines and compost. especially in terms of the reuse of materials in construction. In the private sector the council had topped up government grants to provide full insulation measures to 3026 homes up to 2002.e. It operates a two-bin domestic waste system with a division into dry goods and organic waste. Procurement Where possible the council obtains materials from local sources reducing carbon miles.INTEGRATED DISTRICT ENVIRONMENTAL DESIGN In terms of landscaping the planting of trees and shrubs is encouraged with benefits that include a reduction in the heat island effect. liquid natural gas (LNG) and hydrogen. The council also intends to ensure that its own vehicles will be low carbon technology (i. Sums from the fund are ploughed back into energy efficiency projects. compressed natural gas (CNG). solar shading in summer and protection from wind. The target for all the stock is NHER 9 or SAP 74 with the aim of limiting energy costs to 10–15 per cent of income of those dependent on a state pension. It aims to solve the fuel poverty problem in this sector. It ensures that timber is obtained from sustainably 243 . especially in rented accommodation. Waste The council has adopted plans for a borough-wide zero waste strategy ultimately to reduce the need for landfill disposal to 10 per cent of current use. less than 100 g/km of CO2 equivalent) by 2010–11 when such vehicles should be in volume production. Recycling also plays a major part in its waste strategy. Thermal gasification of other waste provides the hydrogen for the fuel cell. installing community heating. This should eliminate fuel poverty in this sector. building integrated renewable energy systems and requiring water conservation measures to be adopted. Diverting waste from landfill could equate to a CO2 reduction of 100 000 tonnes. The council operates an energy recycling fund which benefits from saving due to energy and water efficiency measures and the recycling/reuse of materials.
remediation and creating the infrastructure of roads and sewers. The landscaping will be irrigated by ground water rather than the mains supply. The township will feature up to 70 000 ft2 of shops and offices serving residents and nearby communities. walkable community where there’s less need for driving’ (Brewer). An innovative stormwater system will reduce runoff by nearly 70 per cent. The EPA considers that the incentives will be sufficient to get PVs on 40 per cent of new homes by 2010 and 50 per cent by 2013.glenwoodpark. ‘to create a sociable. apartments. It is a paradox that. In the context of the norms of American urbanism Glenwood Park is a considerable step in the right direction (www. ‘townhouses’. formed for this project. It will have a mix of individual houses. The ultimate aim is that 1. whilst the Federal government seems to be dragging its feet on climate change issues. Housebuilders will be required to meet the high energy efficient design standards of the EarthCraft House programme which includes not only levels of energy conservation but also water conservation and methods to reduce soil erosion. This means that there will not have to be compromises on standards to satisfy lending institutions. It is estimated that the solar installations would be equivalent to the output from 36 gas fired 75 MW power plants.6 million miles compared with average regional driving patterns which is the equivalent of removing 100 cars from the roads. The street layout will echo traditional European towns with narrower widths and tighter corners than is the norm in US neighbourhoods.com).AN AMERICAN PERSPECTIVE measures and lined with trees and shops. avoiding 50 m tonnes of carbon dioxide emissions. The site is a typical brownfield location which involved demolishing and recycling 40 000 yd3 of site concrete as well as recycling 700 000 lb of granite blocks for use in the parks. A signpost to the future is being offered by the state of California. An important aspect of the project is that it will be totally funded by Brewer’s development company Green Street Properties. Over the past 3 years the company has invested $8 million in buying the 28 acre site. Dedicated cycle lanes will further reduce the need for car travel.2 million new and existing homes will be producing solar electricity by 2017. State subsidies would ensure that householders would make a net gain from exporting to the grid. The object is to be pedestrian friendly. stores and parks interspersed with 1000 trees to moderate the heat island effect. individual states are leading players on a world stage in converting to renewable energy. An existing brick building will be upgraded to supply 22 000 ft2 of office condominiums over covered parking. The residential component of the township will comprise 60 single family houses. 249 . up to 130 townhouses and 200 apartments. There will be direct access to the local rail services which adds up to an estimated reduction in car travel of 1. Its Environmental Protection Agency is proposing that one million homes will be equipped with PVs over the next 10 years in line with a pledge by the state governor.
Another probability is that extreme heat episodes with occur more frequently. The possibility of colder winters adds urgency to the need to tackle the problem of the unacceptable numbers of unfit homes in the UK as outlined in Chapter 10. This will increase 250 . We have noted examples of the predicted rate of return of the 1 in 100 year storm as currently defined. It is inevitable that. At the same time there is a possibility that winters will become more severe due to the weakening or rerouting of the Gulf Stream. Newhaven headed the list with a return rate of 1 in 3 years by 2030. This may change and mechanical ventilation incorporating some form of cooling will become a necessity such as aquifer or ground source cooling. The best we can do is identify the developing technologies and socio-economic trends that are clearly discernible and extrapolate from them. Much greater extremes of temperature will have major design implications. Rainfall patterns will change. As fossil fuel prices rise. At present natural ventilation and the omission of air conditioning is justified on the grounds that cooling is only required for a short period in a year. In the south it is anticipated there will be much less rainfall and frequent drought conditions. There is little doubt that global warming will trigger changes that will fundamentally change the practice of architecture. both for the stability of materials and the levels of insulation. as heat is built up within the biosphere. Already the prediction that global warming will lead to greater intensity and frequency of storms is being realised. this will increase the appeal of building integrated renewables plus active solar heating and seasonal heat storage. this results in the release of energy which powers more extreme climate activity. There are some predictions we can make with reasonable confidence and consider the implications for architects and related professions. This needs to be considered when incorporating passive solar design and the design of atria and conservatories.
workshop. 251 . On a global scale there is no real optimism about the capacity of current renewable technology to meet the energy needs of the next century especially the exploding economies of the Far East. with the doomsday scenario of a 110 metre rise if Antarctica melts (Sir David King. In the north rainfall amounts will rise. The design of substructures and foundations will need to take account of progressive drying out of clay subsoils. The more immediate threat lies in storm surges since a small rise in sea level greatly amplifies the impact of a storm surge. Physicists from Germany. In areas which will increasingly be threatened by flooding. 6 January 1996). It’s a case of ‘watch this space. Antimatter is destroyed when it comes into contact with normal matter. one answer could be that new homes should have the living accommodation at least 2 metres above ground level. For example. namely the exploitation of antimatter. devastating floods hit Boscastle in Devon in 2004 with 75 mm (3 inches) of rainfall in 15 minutes. on the threshold between science fiction and reality is the greatest potential energy source of all. increasing the risk of flash floods as rivers rise and the surrounding land is saturated. Add to this the fact that the predicted intense low pressure systems can cause the sea level to rise locally by over half a metre. The predictions of rising levels are becoming more alarmist.EMERGENT TECHNOLOGIES AND FUTURE PROSPECTS the pressure for water conservation and the harvesting and purification of both rainwater and grey water for use other than for human consumption. The least we can expect is a rise of 1 metre over the next century due mainly to thermal expansion. Italy and Switzerland have managed to combine single antiprotons and positrons to create antiatoms of antihydrogen. clean energy. More than ever before there is hope that someone will find the ‘Rosetta Stone’ that will redefine physics and lead to limitless cheap. There are still those who put their faith in the commercial application of nuclear fusion perhaps relying on the fact that an energy vacuum will radically alter the definition of ‘commercial’. This will have an impact not only on where we build but the way we design buildings. For example. releasing massive amounts of energy (New Scientist. but don’t stand too close’. Already there are compelling reasons not to develop below the 5 metre contour at or near the coasts. It is unlikely that the Environment Agency will have the resources to provide protection against the prospect of an increasing threat. ‘Antiworld flashes into view’. It is inevitable that sea levels will rise. However. with garages. and you have the recipe for serious sea incursion. At the same time there is considerable anxiety about allowing the proliferation of nuclear technology. this goal still seems as elusive as ever. leisure activities below. Energy for the future If demand continues to rise at the present rate it is expected that most of the world’s fossil fuel resources will run out around the middle of this century. Chapter 2).
One of the leading think-tanks in this sphere is the Electric Power Research Institute (EPRI) at Palo Alto in California.’ It will of course be the perfect way to exploit renewable energy. The challenge which the EPRI presents is to provide a minimum of 1000 kWh of electricity per year to everyone in the world by 2050. we will need power delivery systems with switching operations that reach the speed of light. about the same as the US in the 1920s. So-called intelligent grids which can receive as well as distribute electricity at every node are already emerging. The electricity distribution system will have to undergo major changes to cope with this development and with the expansion of smaller scale. This is fatal for microprocessors which are upset by millisecond disturbances. The revolution which will make this vision possible is the shift from mega power plants and creaking national grids to much smaller dispersed grids. he 252 . The transition towards a low-emission energy system would be greatly helped by the development of new means of storing energy on a large scale. This in part will be driven by the digital revolution. p. remembering that by then the estimated global population will be 9–10 billion. Another Yeager suggestion is that we create DC microgrids which. all-electricity plant towards smaller and more numerous combined heat and power plants. In the UK it is claimed the grid is well over its 30 year replacement date. By 2050 this will have risen to 5 billion unless there are fundamental changes in the way we produce and distribute electricity. Energy. intermittent renewable energy sources.9999999 per cent. At present the reliability is 99. Its chief executive Kurt Yeager points out that 2 billion people are without electricity. 22nd Report. 169. the Changing Climate. Large overland grids are inefficient and expensive to maintain. The Royal Commission on Environmental Pollution sees: a shift from very large. Above all. This would be the equivalent of tripling the world’s generating capacity which translates to building a 1000 MW power station every two days. Stationery Office. the answer is to devote massive resources to the development of renewable energy technologies to harness a mere 1/15 000th of the energy of the sun.9 per cent which amounts to stoppages of a few minutes at a time but adding up to about 8 hours a year. They are subject to frequent failure and even at the best of times incur up to 10 per cent line losses. As Yeager puts it. as computers get faster they will require reliability of power in the order of 99. 2000 This ties in with the Washington Worldwatch Institute which states that ‘An electricity grid with many small generators is inherently more stable than a grid serviced by only a few large plants. Solar energy promises unlimited free meals.ARCHITECTURE IN A CLIMATE OF CHANGE The predicted rise in oil consumption considered in Chapter 2 is nothing compared with the anticipated demand for electricity.
1). will.EMERGENT TECHNOLOGIES AND FUTURE PROSPECTS says. heat and water. As indicated earlier a fuel cell is a reactor which combines hydrogen and oxygen to produce electricity. solar panels and hydrogen powered fuel cells. In effect it is a continuously regenerating battery in which the chemical equivalent of combustion takes place to release energy. ‘eliminate much of the imperfections in the sine wave that creates the upsets for microprocessors – those millisecond or nanosecond disturbances’ (Electrical Review. p. A charge separation occurs with protons allowed to pass through the PEM to the cathode but not the electrons. He is one of many who believe that the fuel cell is the power source of the future. 27). in turn. These are diverted to power an external circuit. powers conventional generators. at the same time. The circuit is completed to allow the protons and electrons to recombine at the cathode to produce pure water (Figure 21. A cluster of graphite anode rods surrounds the cathode. Most significant of all is his prediction that in the future most of our electricity will come from millions of micro-turbines. performing the function of a sewage treatment plant. Now there is on the horizon a system of producing electricity directly from a microbial fuel cell (MFC). Researchers at Pennsylvania State University have a developed a device which serves dual roles of generating electricity and. The route to electricity from sewage is normally via the digestion process which produces biogas which. The bacteria in normal sewage treatment use enzymes to oxidise organic material and in the process release electrons.1 Microbial fuel cell (derived from New Scientist) 253 . 10 October 2000. The MFC is a cylinder with a central cathode rod surrounded by a proton exchange membrane (PEM). Water Power circuit Cathode – + Anode Air Liquid input Water Figure 21. Bacteria become attached to the anodes causing the organic waste to be broken down into electrons and protons.
Producing hydrogen by the electrolyser method is fairly energy intensive and not carbon free unless it involves carbon neutral generation systems. p. The next step in the progression is to create cells which absorb light in the infra-red part of the spectrum. there is considerable further research and development to be undertaken and it may take another 20 years for it to achieve the scale of output which would make it commercially viable (New Scientist. These would be coated with 254 . But. Most renewable systems are intermittent and hydrogen supplies the so-called flywheel effect smoothing out the peaks and troughs. It is also transportable so has universal application.2). The carbon dioxide (CO2) balances that absorbed by the biological waste during growth. carbon monoxide and carbon dioxide. The holy grail of energy is the fuel cell that creates power with absolutely no polluting emissions. The gases pass to a cooling chamber reducing the temperature to 400 C. High unit cost is the barrier which is preventing production achieving economies of scale. The solar cells of the future are likely to use thin film technology. They absorb light strongly in the red and green parts of the visible spectrum. 21). But here again things could be about to change. They then pass across a second catalyst (platinum and cerium oxide) which causes the carbon monoxide to react with the hot water producing carbon dioxide and hydrogen in a 50–50 split. The initial heating process could be assisted by evacuated tube solar thermal collectors (Figure 21. This system could be scaled up to supplying grid-scale fuel cells by using a combination of agricultural waste and dedicated rapid rotation energy crops. As the first prototype. Ethanol (alcohol) is produced by the breakdown and fermentation of crop waste or fuel crops. the most obvious renewable electricity source is the solar cell. The ethanol and water are mixed with air and then heated to 140 C causing the mix to vaporise. Some of this heat is used to heat up the incoming mixture. That will happen when the electrolytic process to split water into oxygen and hydrogen is driven by zero carbon renewable energy systems. if you are already producing carbon-free electricity why incur an efficiency drop by creating hydrogen? The obvious answer is that it is the way of ensuring continuity of supply. A less carbon intensive alternative being developed is the hydrogen generator fuel cell (HGFC). for example titanium-oxide coated nanocrystals with ruthenium dye which mimic photosynthesis and which are now being developed in Switzerland. The gas then passes over a catalyst (rhodium and cerium oxide) which increases the temperature to 700 C and breaks down the ethanol into hydrogen.ARCHITECTURE IN A CLIMATE OF CHANGE This is the first MFC designed specifically to process human waste. Its fuel is a mixture of ethanol and water. 13 March 2004. Next generation solar cells From the point of view of buildings. They should prove to be a fraction of the cost of silicon-based cells.
So. p. Michael Gratzel of the University of Lausanne estimates that a 10 per cent conversion rate should be possible (New Scientist. Others are looking at capturing energy using biological rather than electrochemical cells. 34–37). What really surprised the researchers was that it absorbs 97 per cent of infra-red part of the spectrum and even extends into the microwave end of the spectrum. This is literally mimicking natural photosynthesis.EMERGENT TECHNOLOGIES AND FUTURE PROSPECTS a dye that is transparent yet still absorbs enough in the invisible part of the spectrum to provide electricity. 40). It resulted from etching silicon with a powerful laser hundreds of billions of times brighter than the sun. Normally a single photon knocks one electron out of the crystal structure creating a current. In 2004 it was reported that a team in the Los Alamos National Laboratory in New Mexico had found a method of considerably increasing the efficiency of crystalline solar cells. 13 January 2001. Creating the solar cell which will use an organic solid to replace the liquid electrolyte of conventional cells is Gratzel’s latest objective. However. A chance discovery in a laboratory could be the key to the ultimate breakthrough in solar cell technology. in current terms. A normal silicon cell will absorb only about half the light that falls on it. when a high energy photon hits a nanocrystal semiconductor the extra energy liberates two or even three electrons. The result was a jet black structure of microscopic spikes which absorbs 97 per cent of visible light. being transparent. At 97 per cent absorption rate the black silicon photovoltaic cell could represent a quantum leap in efficiency and therefore cost effectiveness (New Scientist. ‘biomimicry’. pp.2 Compact fuel cell hydrogen generator (courtesy of New Scientist) 255 . Not only does this create a whole new field of opportunity for communications it could also herald the birth of much more efficient solar cells. Normal grey silicon is transparent to infra-red light. they will have an application for windows as well as roofs. A solar cell which Figure 21. 23 January 1999.
Solar cell technology will achieve its ultimate breakthrough when it is coupled to an effective electricity storage system. 28 May 1997). 28–31). pp. This is yet another application of nanotechnology. Energy storage At Baltimore University there is a project to produce an all-plastic battery. Electricity will run around the cables with no power loss until it is needed either for the grid or a stand-alone use. Photosynthesis is ‘the most successful solar converting mechanism on Earth’ (New Scientist. but where cars go buildings cannot be far behind (Autocar. 16). However. hydrogen ions and electrons. 1 May 2004). In this process sunlight splits water into its constituents of oxygen. The task now is to raise the efficiency to ~10 per cent. Already operational cells have been produced that have polymers as both anode and cathode with a special solid plastic gel as the electrolyte. 15 May 2004. there is the prospect of storing massive amounts of electricity in a ring of superconducting cables. a team at Imperial College. (www. Up to now the way plants perform this miracle has been a mystery. According to the director of the Interdisciplinary Research Centre at Cambridge University.Azonano. vol. A team led by Professor A. p. The theoretical limit of conventional solar cells is 44 per cent (Physical Review Letters. paving the way for unlimited quantities of sustainable energy (see New Scientist. may have made the crucial breakthrough. Paul Alivisatos of the University of California. having identified a plant’s photosynthetic machinery where water splitting occurs. 601 and reported in New Scientist. 186. The prime target is cars. Within the next decade it may be that scientists will have replicated nature’s most ingenious process.com). 1 May 2004. Artificial photosynthesis The dream of researchers in energy is to replicate the process of photosynthesis to produce hydrogen. Berkeley has made cheap plastic solar cells flexible enough to paint onto any surface. opening up the prospect of producing hydrogen on an industrial scale. The difference between natural and artificial photosynthesis is that the latter is designed only to produce hydrogen. These superconducting reservoirs will be 256 . London. ‘Flower Power’. This is called the ‘catalytic core’ and it provides the platform for research into artificial photosynthesis called ‘artificial chloroplasts’. 92. pp. The quantum leap in storage technology should emerge by around 2020 with the development of high temperature superconductors.ARCHITECTURE IN A CLIMATE OF CHANGE employs this technology could convert 60 per cent of solar energy into electricity.
It is nanofibre carbon. Energy can be drawn off by permanent magnets in the disc inducing electric current in a coil. There is no friction only air resistance and if the system operates in a near vacuum then it would be capable of storing 10 000 watt hours of energy. The inevitable conclusion is that fuel cell. Flywheel technology The problem with flywheels is that the G-forces can cause a catastrophic explosion. solar cell and storage technologies could all be on the verge of commercial viability. p. However. It is claimed that a cartridge in a hydrogen car could fuel it for 5000 kilometres. The future seems to point to materials like composites of carbon fibre and epoxy resin. Over a 24 hour period the loss of energy would be negligible. Space technology is the driving force behind the development of superfast flywheels that can store a considerable quantity of kinetic energy to be converted into electricity. At present the highest temperature at which superconductivity has been achieved is minus 70 C which represents a considerable advance towards the goal of room temperature superconductivity. This consists of cylinders 0. tidal energy (New Scientist. Fuel cells and titanium oxide solar cells are within a few years of presenting a serious challenge to conventional energy systems.4 nanometres (0.4 billionths of a metre) in diameter which is just right size to accommodate a hydrogen atom.EMERGENT TECHNOLOGIES AND FUTURE PROSPECTS ideal for storing power from intermittent renewable sources and will change the whole economic status of. Others are concentrating on small flywheels floating on magnetic bearings and capable of reaching 600 000 rpm with an energy density of 250 Wh/kg. early in the 1990s research in Japan was developing a 3 m flywheel made from stainless steel levitating between powerful magnetic fields generated by superconducting ceramics. for example. A nanofibre pack has the capacity to store up to 70 per cent of hydrogen by weight compared to 2–4 per cent in a metal hydride. More conventional flywheels will prove an economic way of enabling solar energy to cover the diurnal cycle. The outcome of this research remains to be seen. Ultimately interseasonal storage may not be out of the question. These are all systems which store chemical or kinetic energy to be converted into electricity. 19). 26 April 1997. They are being spurred 257 . The flywheel is set in motion by electromagnetic conduction. Hydrogen storage The most promising safe storage technology so far has recently emerged from Japan and Hong Kong. For buildings the storage potential is enormous.
a note of caution. The end of the world of fossil fuels is at hand and beyond it is the much brighter prospect of the post-hydrocarbon society. A large stadium has intermittent use but also huge energy costs. It is estimated that. Solid state light emitting diodes (LEDs) are based on the quantum principle that an atom’s electrons emit energy when they jump from a high energy level to a lower one. There would be a backup system of natural gas to provide hydrogen in the unlikely event that solar panels failed to perform adequately. It also has a massive roof area which could house acres of solar cells dedicated to producing hydrogen easily sufficient to meet the surge of demand for events by day or night. They also have a size advantage. Already the days of the compact fluorescent light are numbered. No more power failures during football matches. According to Scientific American ‘White LEDs are possible. if existing light sources in the US were converted to LEDs. Whereas an incandescent lamp achieves an efficiency of 10–20 lumens per watt. It might require a leap of faith to make the new Wembley independent of the grid but that could be the shape of things to come. an LED of less than one square centimetre would emit as much light as a 60 watt bulb using only 3 watts. For example. LEDs will offer significant savings in annual costs. By adjusting the ‘band gap’ between the two levels. but affordable ones powerful enough to illuminate a room remain at 258 . there would be no need for new power stations for 20 years. The really big incentive is cost.7 per cent. light of different colours can be emitted. It will be made redundant by developments in light emitting ‘photonic’ materials.ARCHITECTURE IN A CLIMATE OF CHANGE on by the pressing need to bring down carbon dioxide (CO2) emissions. Advances in lighting Another technical step change will occur in the sphere of lighting. However. This has enormous implications for the design of buildings now. As lighting accounts for most electricity used in most offices. Within the next 5 to 10 years there should be a quantum improvement in the efficiency of solar cells coupled with a substantial reduction in unit cost. Large structures like sports stadia are particularly good candidates for embedded systems which provide heat and power. LEDs are a by-product of semi-conductor technology and produce light at much lower watts per lumen than conventional systems. Roofs and whole elevations will be able to accommodate solar cells. LEDs are predicted to realise 300 lumens per watt. assuming the present annual rate of increase of consumption of 2. This all bolsters the case for incorporating renewable generation systems into buildings at the earliest stage of design. They are almost unbreakable and have a life expectancy of 100 000 hours. and by anxieties about the security of supply of fossil fuels. particularly when cells have been produced commercially which are transparent.
a lower refractive index.EMERGENT TECHNOLOGIES AND FUTURE PROSPECTS least a decade away’ (February 2001). that is. computers. The limiting factor is the speed of light. The difference in refractive index causes light to be bounced off the outer casing with little loss of intensity over a considerable distance. This will offer much greater freedom to employees as regards their place of abode. in other words. but entirely new kinds of computer architecture 259 . Quite soon the whole world will be linked to an optical fibre superhighway based on photonic materials. Optical fibres can carry up to 25 trillion bits per second. The goal of current research is to create the photonic integrated circuit. Not only will they be faster. rates of transmission of information will increase at an exponential rate. as Philip Ball puts it: The photonic integrated circuit which processes light on a chip … will see computers change qualitatively. Nevertheless. This will herald the next IT revolution when. information processing. It is probable this will lead to a considerable reduction in the need for high concentrations of office accommodation. The second theatre of war was information processing. computer and visual communication will have a major impact on work patterns. One consequence is that teleworking will become much more prevalent. The photonic revolution The battle between traditional electronics is being fought on two fronts: ● ● information transmission. Towns and cities will compete on the basis of amenity and quality of life since people will have much greater freedom as to where to live. At present optical fibres require electronic devices to convert information into optical pulses and. one that is free of electronic mediation. Particles of light – photons – can carry many thousands of times more information than wires. High capacity communication systems based on a multimedia supercorridor accommodating audio. Already teleconferencing is reducing the need for costly gatherings of executives as companies spread their operations globally. enabling commercial enterprises to scale down their centralised operations. Optical fibres work by trapping light within a solid rod of glass which is surrounded by a cladding material with different optical properties. that is. what all this amounts to is that wholly electricity autonomous buildings should be an economic reality around a decade from now. We are already into the era when information is transmitted by pulses of light rather than through a copper wire. This will be further driven by developments in transport. Because of this. avoiding the necessity of being connected to the grid. to decode the information. at the receiving end. than the core.
we will discover new ways to make machines think. This will dispense with the need for mechanical blinds and solar shades and will give individuals much greater control over their immediate environment.’ (Made to Measure. As Philip Ball puts it: ‘Smart materials represent the epitome of the new paradigm of materials science whereby structural materials are being superseded by functional ones’. use a fraction of the energy of an electronic computer and generate virtually no heat. Princeton. This will make a significant impact on the energy demand of the standard office. As the frequency or amplitude of the vibrations changes so the feedback loop modifies the reaction to compensate. It will also have implications for design of the building fabric and the services. Couple this with the introduction of LEDs and it is certainly conceivable that commercial buildings will more than meet their energy demands by means of the next generation of photovoltaic cells. In many situations they will replace mechanical operations. 104). Such materials come into the general category of passive smart materials. The autonomous office is nigh. An example is a vibrating–damping smart system. In other words. We will see ‘smart devices in which the materials themselves do the job of levers. gears and even electronic circuitry’. The current is required to change its state not to maintain that state. 1997 p. like thermochromic or electrochromic glass. At present electrochromic glass is a sandwich construction with a gel which changes its light emission properties in response to an electric current. 58) Computers are major consumers of energy not only in use but also because of the heat they generate which often must be disposed of mechanically. Smart materials are already on the market. An active system is controlled not only be external forces but also by some internal signal. There is even the prospect of ‘A house built of bricks that change their thermal insulating properties depending on the outside temperature so as to maximise energy efficiency’ (op. In smart systems an active response usually involves a feedback loop that enables the system to ‘tune’ its response and thus adapt to a changing environment rather than be passively driven by external forces. Mechanical movement triggers a feedback loop into providing movement that stabilises the system. Smart materials carry out their tasks as a result of their intrinsic properties. The all-photonic computer will be much faster. The really exciting advances are in active smart materials. cit. 260 .. Smart materials Materials science is entering a whole new realm. p. Pilkington is developing a solid state version of this glass which should make both cheaper and available in much larger sizes.ARCHITECTURE IN A CLIMATE OF CHANGE should become possible.
that get smarter as they get older. In principle SMAS can be used for any application which requires heat to be converted into mechanical action. They can be incorporated into mechanisms for operating ventilation louvres or ventilation/heating diffusers. They function by virtue of the fact that the crystal structures of SMAS change when heated. return completely to their former shape. after deformation. There is yet another dimension to the characteristics of smart materials – materials that learn. They have the potential to replace a range of mechanical devices such as vehicle clutches. Buildings would be constructed off concrete rafts which in turn would be supported by an array of magnetorheological dampers. They can be made intelligent by coupling them to sensor devices which detect sudden movement. certain fluids can change to a near solid state. These are materials which. An application already being exploited are thermostats where bimetal strips are replaced by alloys. In general smart systems can be divided into sensors and actuators. Linked to sensors they would be ideal for buildings in earthquake zones.’. it seems ‘such stuff as dreams are made of’. They are called ‘electrorheological fluids’ (rheology is the study of the viscosity and flow capacity of fluids). they are control devices that close or open an electrical circuit or act as a valve in a pipe. They have an inbuilt degree of intelligence and are capable of optimising. Actuators make things happen. No moving parts. At the onset of vibrations these would instantly change from solid to fluid and soak up the movement of the earth. If the end of the last century was 261 . they may perform a dual role extracting heat from low grade sources like ground water or geothermal reservoirs and serve as mechanical pumps to deliver the warmed water to the heating system of a building. Another class of smart fluid is activated by being exposed to a magnetic field. springs and dampening devices to eliminate mechanical vibrations. Smart fluids By introducing a strong electrical field. Sensors are detection devices to respond to changes in the environment and warn accordingly. For example. no possibility of mechanical breakdown and all at low cost.
We will learn to be adaptive rather than assertive. Add to this the fact that people are increasingly obtaining goods and services 262 . Many would agree that: The cold economic rationality of capitalism. It might also have a negative effect on quality as price alone is the deciding factor. Each day trillions of dollars move around the global money market as corporations locate their transactions in low tax jurisdictions. The Observer. The meteoric growth of ‘turbo-capitalism’ with its single-minded purpose of optimising market opportunities is likely to lead to a sharp decline in public funded services. the future. This will have an impact on procurement as the public sector building realm declines. Despite the rail chaos of late 2000 and early 2001. It is likely and desirable that the Rogers Task Force (recommendations will be influential in the design of the next generation of new towns Towards an Urban Renaissance. 2 January 2000 One outcome of the development of IT is that the economic and business certainties of the twentieth century are disintegrating. ‘may hold an increasing simplicity. in turn. p. motorists are showing no sign of responding. Socio-economic factors The focus of the book began at the global scale and gradually sharpened down to the detailed design of buildings. in which every institution is subordinated to the calculus of profit and loss. At present the average distance travelled by car per day is 28 miles. By 2025 it is expected that this will rise to 60 miles. hypermobile society. it is still the view that superfast trains will be in service within the next decade which will create the conditions for a more dispersed. mostly in southern England. 142). We are social as well as economic beings. This.ARCHITECTURE IN A CLIMATE OF CHANGE characterised by the rise of high technology with ever more complex electronic wizardry packed into ever smaller spaces. as materials replace machines’ (Ball. given added impetus by the demographic changes that have created the need for 4 million new homes. does not answer the question posed by every human being – that there is more to life than the pursuit of economic efficiency.. This surely is what environmental responsibility is all about. It seems appropriate to end by again speculating more widely about socio-economic issues which will affect all who operate within the construction industry. will create a demand for new kinds of development. It seems inevitable that there will be a new crop of new towns but designed to a high density. As electronic commerce grows. June 1999). cit. governments will find it ever harder to raise taxes. op. Despite government exhortations to convert to public transport. according to materials scientists.
One scenario is that the growing gap between the poor and the affluent will continue to widen. Many circumstances are conspiring to ensure that. Within the current economic climate. The power of the nation state will weaken. London.. Those without are likely to emerge as losers. If this prediction is realised. Change is inevitable. 1999). the prospect of runaway global warming becomes a virtual certainty and that’s not an inviting prospect for our children and grandchildren. pump-priming them so that they quickly achieve economy of scale. to spend money now to limit catastrophic climate change in 50 years’ time is not an efficient way to deploy capital. security will become a major design determinant in all types of building. As Ian Angell (head of the Department of Information Systems. Other nations subsidise technologies. On the positive side. The Information Age will be kindest to those who adapt. with obvious consequences for the social services. according to Professor John Adams of University College. we are likely to see the well-off retreating into gated and guarded communities (The Social Implications of Hypermobility. The UK has the expertise but will not be a key player if it continues to be fixated on short-term profits and allows capital costs to outweigh the benefits of medium-to long-term revenue gains. A rising crime rate will lead to anxieties which increase the attraction of buying the necessities of life though the Internet with obvious consequences for high street and even neighbourhood shops. New Scientist. 263 . The dividing line will become sharply defined as between those with IT and communication skills who can keep up with the pace of change and those who increasingly fall behind in this new Darwinian environment. 4 March 2000. pp. Those who don’t. Instead. or those whose citizens are isolated from the new ways to communicate. we should also be accumulating a contingency fund to deal with the future effects of global warming that are inevitable due to the momentum generated by past emissions of greenhouse gases. if we do not revolutionise the way we produce and distribute energy. there are huge economic opportunities to be grasped in the development and manufacture of products related to the sphere of sustainability. Communities that invest substantially in communication technologies will thrive. The reality is that we should not only now be imposing severe constraints on the use of fossil fuels. 44–45 This progressive bi-polarisation will produce social tensions with decreasing social cohesion and an increase in crime. will suffer.
ARCHITECTURE IN A CLIMATE OF CHANGE Of this there can be no doubt: the next decades will witness the accelerating pace of change. 264 . Later in the century. huge uncertainties emerge. the growing tensions arising from competition for access to water and fertile land exacerbated by the widening gap between rich and poor. For the early part of the century it is likely that wealth will increase. Designers within construction have it in their power to help with the solution rather than add to the problem. mainly associated with the social and political consequences of climate change.
ensuring that designs meet the highest standards of technical proficiency in combination with aesthetic excellence. Ensuring that building management systems are user-friendly and not overcomplex.Key indicators for sustainable design Appendix One ● ● ● ● ● ● ● ● ● ● ● ● ● ● Minimising the use of fossil-based energy in terms of the energy embodied in the materials. Exploiting the potential for natural ventilation in the context of an overall climate control strategy which minimises energy use and maximises comfort. Minimising the use of water. Identifying the potential for exploiting the constant ground temperature for evening out the peaks and troughs of summer and winter temperature. Making best use of passive solar energy whilst employing heating/cooling systems which are fine-tuned to the needs of the occupants with air conditioning used only in exceptional circumstances. 265 . Designing to make maximum use of natural light whilst also being aware of its limitations. Whilst taking account of these key indicators. harvesting rainwater and grey water and purifying for use other than human consumption. Creating an external environmental which is both a visual amenity and also offers environmental benefits such as summer shading from deciduous trees and evaporative cooling from water features. Identifying opportunities to generate on-site renewable electricity (embedded systems). Avoiding all ozone depleting chemicals in terms of manufacture and system operation including HCFCs. Minimising rainwater runoff by limiting the extent of hard external landscape. Making best use of recycled materials and renewable materials from a verifiable source. Where possible using alternatives to materials containing volatile organic compounds. transport and construction process and the energy used during the lifetime of the building.
266 ..
‘Soft’ assets: soil. soil formation and waste assimilation. Natural resources and pollution Global natural assets. The evidence Rise in sea level over the past 150 years. e. Soil exhaustion through intensive use of agrochemicals. rise in surface global temperature and temperature records in the last decade. Nuclear waste disposal and decommissioning of nuclear power stations. fixed and finite.An outline sustainability syllabus for designers Appendix Two The change to environmentally advanced design needs to be driven by a conviction that it is necessary. Salination as a consequence of hydroelectric schemes and runoff. increasing intensity and 267 . e. minerals and fossil hydrocarbons. oceans. The carbon cycle and current imbalance. forests. Processes: photosynthesis.g. Soil erosion and oxidation. Evidence of past fluctuations and link between global temperature and CO2 in the atmosphere. troposphere. acid rain and low level ozone. hydrological cycle and carbon cycle. Predicted problems associated with resource depletion coupled with estimated population growth (11 billion by 2050). Climate change The mechanism of the greenhouse. Continued deforestation in tropical and temperate rain forests. Contaminated land and remediation strategies. Problems associated with pollution.g.
Potential changes in ocean currents. effects on health. International comparisons of per capita annual CO2 emissions (UN statistics). SE Asia. threat to the Gulf Stream from melting Greenland ice. including the external costs in fixing fossil fuel prices. Rising sea levels through expansion and melt ice threatening island states. The Hague. crops. severe heat episodes. e. melting of polar ice and glaciers.g. Predictions IPCC predictions regarding level of atmospheric CO2 by 2050 assuming ‘business as usual’ (at least double pre-industrial level) and consequent temperature rise. India. Steeper pressure gradients and deeper troughs more intense and more frequent storms. China. Scientific evidence for attributing most of the change to human activity (UN IPCC report 2001). Concept of carbon trading and international agreements: Rio. Kyoto. damage to crops and wildlife of low level pollution. migration to temperate zones of subtropical diseases. The ‘externalities’ include the contribution to global warming. Future prospects for availability of fossil fuels based on latest estimates of reserves. animals and diseases. The outlook for conventional energy. Ozone depletion Caused by CFCs and HCFCs creating aerosols in the upper atmosphere which erode the ozone shield which protects against ultra-violet radiation. Nuclear outlook including scenarios in Royal Commission on Pollution Energy Report. The case for a shift from neo-classical economic theory which regards the Earth’s assets as free to eco-economics which factors in the environmental and social costs of human actions. Projections of energy consumption: US. Migration of plants. Present position compared with pre-industrial in terms of temperature and level of atmospheric CO2. Increase in temperature greater energy in the system greater turbulence.ARCHITECTURE IN A CLIMATE OF CHANGE frequency of storms and floods. e. maritime cities and coastal agricultural belts. 268 . Problems arising from the rate of climate change exceeding adaptation capacity of forests. This causes skin cancer and damages the immune system plus damage to crops. Europe.g.
the ‘Tapchan’ system. rapeseed diesel. coastal and offshore oscillating water column. photovoltaics. Heat reflecting and heat absorbing glazing. innovative techniques.AN OUTLINE SUSTAINABILITY SYLLABUS FOR DESIGNERS Renewable technologies Marine systems Hydroelectric generation. liquid fuels. thermochromic and electrochromic glass. inorganic. small-scale hydro. hydrogen. synthetic organic. Windows and glazing Types of energy efficient glazing with U-values. Other renewable technologies The solar chimney. Photochromic. Technical risks of insulation. aerogels. direct combustion from rapid rotation crops. impoundment systems. wind power. Low energy housing Passive solar design. solid state electrochromic glass. nuclear.g. wave power. thermal bridges. ‘run-of-river’ systems. thermal concentrator. double sided collector. Thermal conductivity of various insulation materials. 269 . Construction techniques High and superinsulation standards and specimen built examples. Developments in glass technology. power from biomass and waste. frame. underwater turbines. Active solar thermal systems: flat plat solar collector. Net U-values including solar gain. tidal energy – barrage systems and the tidal fence. Insulation Types of insulation material and thermal performance: natural organic. Construction systems: masonry. geothermal energy. Trombe walls. biogas. Transparent insulation materials. e.
NHER. Singleton near Chichester. Buildings in use account for 47 per cent of total UK CO2 emissions with an additional 5 per cent for those under construction. Sibelius Concert Hall. Wintergardens. Sheffield. Means of ensuring that timber originates from a sustainable source. Summary Checklist for the energy efficient design of dwellings. Finland. Thermal mass and the ‘flywheel’ effect. Cardington. Multi-storey experimental timber house by the Building Research Establishment. Beddington zero-energy development (BedZED). Lahti. Embodied energy in materials. 270 . Remote and integrated systems. Nottinghamshire. Examples: ‘House of the Future’. Types of PV cell and energy output. Advanced and ultra-low energy housing – examples Hockerton self-sufficient housing project. BEPI and CO2 measure. Museum of Welsh Life. New centre at Weald and Downland Open Air Museum. Housing – the existing stock Assessment methods for energy efficiency: SAP. Heating. ‘House of the Future’ Museum of Welsh Life.ARCHITECTURE IN A CLIMATE OF CHANGE Domestic energy Photovoltaics (PVs) and the principle of PV generation. Timber construction The environmental benefits of timber in construction.
5 per cent of the total comes from older building stock. 29 per cent comes from housing. Standards for domestic warmth defined as ‘adequate’ and ‘minimum’. and Peabody Trust. building management systems (BMS) Energy storage: underground thermal storage. passive solar design. Energy options ● ● ● ● ● ● ● ● Carbon intensity of different fuels Energy distribution in a combined heat and power (CHP) system The fuel cell. Cornwall. dense storage medium Electricity storage to overcome intermittence of supply by renewables: – Latest battery technology. pump storage – Creation of hydrogen by reformation of methane etc. Penwith. Offices and institutional buildings Six performance indicators from Movement for Innovation (M4I). State of the housing stock from English House Condition Survey 2001. examples: Commerzbank and Swiss Re Ventilation and air movement. Incidence of fuel poverty as defined by DETR and health problems directly attributable to poor housing. Retrofit examples. this rises to 75 per cent. e.g. phase change materials. Energy use across appliances. Environmental considerations in the design of offices. Of this total. basic operation of the fuel cell Storage techniques – electricity Storage techniques – warmth and cooling PV applications. and by dedicated PV/electrolyser 271 . heating and cooling. Construction technologies: climate facades. summary of recommendations Air conditioning as distinct from mechanically assisted ventilation. Breakdown of SAP ratings across the stock. floors and ceilings. 98.
daylight linked control. problems relating to occupants and managers. common engineering problems. Earth Centre. High profile–low profile. glare. risks regarding timber and quality control. light shelves. e. building related illness/sick building syndrome. heat gain. 272 . occupancy linked control. ● Tools for environmental design Lighting – designing for daylight Factors influencing levels of daylight. Summary of recommendations Life-cycle assessment and recycling BRE Ecopoints system for construction materials and components. solar shading.ARCHITECTURE IN A CLIMATE OF CHANGE – Hydrogen storage by pressurised tanks.g. Recycling strategy checklist. metal hydrides – Regenerative fuel cell storage and ‘Regenesys’ technology Building management systems and Building Energy Management Systems. Lighting controls and the human factor Post-occupancy analysis and differences between expectation and reality.g. Further reference to embodied energy. Design considerations – danger of excessive contrast. timed controls. operational difficulties. Precautions regarding recycled materials. Environmental design and common problems The ‘Probe’ studies and the lessons from post-occupancy analysis. common architectural problems. localised switching. switches. Recycling case study. holographic glazing. Conditions for successful design. e. the ‘high-tech’ demand. dimming control and occupancy sensing. common failures leading to energy waste. inherent inefficiencies. the human factor. low energy Conference Centre. prismatic glazing. photoelectric control and the human behaviour. air conditioned offices. e.g. The atrium. light pipes. Doncaster (Bill Dunster). system management. Whole life costing.
Linz Solar City. smart materials. smart fluids. Emergent technologies and future prospects Recap of the likely consequences of global warming as they affect buildings. impact of economic PVs for embedded installation. Case study: Ecological City of Tomorrow. next generation solar cells. polymer batteries. socio-economic factors.AN OUTLINE SUSTAINABILITY SYLLABUS FOR DESIGNERS Integrated district environmental design Beyond the individual building. energy storage: hydrogen storage and the potential of nanofibre carbon. shift from mega power plants to many smaller dispersed generators using a range of renewable technologies. Examples: Plan-les-Ouates solar city near Geneva. Austria. advances in lighting – LEDs. electricity storage. energy for the future. Malmo. implications of expansion of IT and the impact of optical fibre technology. flywheel technology. emergent technologies for combined heat and power systems for groups of houses or commercial/institutional buildings driven by micro-turbines. high temperature superconductivity. the photonic revolution. 273 . Sweden.
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87–9 photovoltaic systems. 184–5 Autonomous developments. 83 Coventry University Library. 206–7 275 . 34–5 Body tinted glass. Devon. 1–2 Carbon Dioxide Profile. 28–9 Atrium. 90–1. Manchester University. 94. 217–18 renewable energy centre zero emissions building. 10. 52–4 framed construction. 223–5 Biomass utilisation. 152–3 Copper indium diselenide (CIS) cells. 133 Cold-related illnesses. 117 Domestic energy. 19–20 outlook. 2. 86–7 polycrystalline silicon. 111 David Wilson Millennium Eco-House. 77 Air conditioning. Doncaster. 52–3 Contact Theatre. 60 Construction systems. Fulham. 107 offices. 192 avoidance of. 130–6 Clouds. 256 Arup Research and Development Report. 166 Amorphous silicon cells. 181–2 See also Lighting Demonstration House for the Future. 177–8 Beaufort Court. 3–4. 93 Autonomous House. 209–11 Conservatories. 17–18 Climate facade. See Insulation Climate change: causes of fluctuations. 49 Blue Energy tidal fence system. 130–6 Aerogels. 180 Aswan Dam scheme. 87–9. 225–34 renewable energy sources. 19–20 paleoclimate record. 238–9 Cladding. 49–50 Building energy management system (BEMS). 48–9 direct combustion.Index Active facade. Lillie Road. 198–9 Alkaline fuel cells (AFC). London. 99–100 Business as usual (BaU) scenario. 120–1 Combined heat and power (CHP). Frankfurt. 7. 80. 47–8 liquid fuels. 116–17 Concrete. 84. 47–9 biogas. 12–14 Cadmium telluride (CdTe) cells. 71 City transformation. 83 energy output. 125–6 Cellular glass. 91–2 fuel cells. 14–15 abatement strategies. 94–5 Daylight. 20–1 Co-operative Headquarters. 7–11 control strategies. 83 Carbon cycle. 80–92 embodied energy and materials. 53 innovative techniques. 4–7 evidence for human causation. 149–50 Domestic appliances. Earth Centre. 124 Batteries. 124–5 Earth’s axial tilt. South Wales. 80–7 amorphous silicon. 83 cadmium telluride (CdTe). 3–4 predicted effects. 82–3 principle of. 95–8 Displacement ventilation. 140–3. 206–7 Conference Centre. London. 162–3 Commerzbank. 154–6 Composting toilet. 174 Building Research Establishment timber-framed apartments. 53–4 masonry construction. 119 Building of the Future. 83 copper indium diselenide (CIS). 12–17 recent uncertainties. 83 Antimatter. 218–25 energy package. Egypt. 140 Darrieus-Rotor. 146–8. 253–4 micro-combined heat and power (CHP). 143–5 Cool storage. 178–9 Building Energy Performance Index (BEPI). 251 Architectural Salvage Index. 175–6 Cooling strategies. 231–4 solar design aspects. Manchester. 70 Cellulose. 203–4 Artificial photosynthesis. 4–5 Eco-cement. 250 evaporative cooling. 17–18 CO2 levels. 119 Cavity wall filling. 81–2 Dry lining. 226–31 Beddington Zero Energy Development (BedZED). 66 Borehole heat exchange (BHE) system. 151–4. 116 Baggy House.
205 El Niño. 29–30 small-scale hydro. 154–9 Ecopaint. 17–18 See also Climate change Greenhouse effect. 10–11. 199 See also Domestic energy Energy efficiency: House Condition Survey. England. 176–7 See also Electricity wastage. 29 Hydrogen. 67 Glazed curtain wall. 252–4 intelligent grids. 116 Holographic glazing. Malmo. 252 Electricity. 111 Hemp. 162 storage. 118–19 Building Energy Performance Index (BEPI). 2. 67. 184 Heat pumps. 259–60 Information transmission. 257 regenerative fuel cell. Georgia. 119 Carbon Dioxide Profile. 3 outlook. 257–8 Forest growth. 174–7 cool storage. 119–20 House Condition Survey. 23–4 outlook. 169. 256–7 heat storage. 5–6 H-Darrieus-Rotor. 130 Glenwood Park. 163–9. 251–4 primary. England. 121–2 Geopolymers. 91–2. 256–7 batteries. 165 proton exchange membrane fuel cell (PEMFC). 8–9. 166–9 phosphoric acid fuel cell (PAFC). 118–19 Energy efficient design. England. 70 Flat plate solar thermal collector. 260 Electrorheological fluids. 49–50 Glacial melting. 177–8 flywheel technology. 28–30 ‘run of river’ systems. 170 Electrochromic glass. 9–11. 106–7 Energy use: burning of fossil fuels. 8 Electric Power Research Institute (EPRI). 250 control strategies. 169. 169–70. 50. 261 Embedded energy generation. 66 prismatic glazing. 3–4 Ice sheet collapse. 118–19 fuel poverty.INDEX Eco-materials. 12–17. 93. 121–2 standards. 61–2 Fuel cells. 250 recent uncertainties. 56–7. 175–6 future technologies. 236–8 Ecological tower blocks. 124–5 case study. 16 Fossil fuels. 254 Ice core data. 91–2. 68–79 276 . Renewable energy sources Environmental Systems Performance Model. 104–5 built form. 2. 111 Hallum University. 119 National Home Energy Rating (NHER). 251 recent increases. 26–8 See also Domestic energy. 175 Heat-related deaths. 179 Ethanol as power source. 3. 177–8. burning of. 162 future demand. 120 insulation: benefits. 175 seasonal energy storage. 168. 119–20 Humidity. 170 solid oxide fuel cell (SOFC). 162 embodied energy. 70 electrochromic. 120–1 remedy. 104–7 building features. 66 thermochromic. 257 See also Fuel cells Hydrogen generator fuel cell (HGFC). California. 152–3 Existing housing: energy efficiency measurement. 105–6 passive solar heat gain. 206–7 concrete. Sweden. England. 8–9. 119 Standard Assessment Procedure (SAP). 71 Flooding. 65–6 cellular. 20–2 UK energy picture. 185 reflective coatings. 105 systems. Atlanta. 207 Ecopoints. 121–2 heating standards. 208–9 Energy: delivered. 207–8 Ecological City of Tomorrow. 71 Hockerton Housing Project. 122 cavity filling. 20–2 nuclear option. 67. 64–7 body tinted. 166 hydrogen generator fuel cell (HGFC). 125–6 Expanded polystyrene (EPS). 15 Heating: House Condition Survey. 80 See also Domestic energy Embodied energy. 103–4 Extruded polystyrene (XPS). 164–5 regenerative fuel cell. 120–1 remedy. 252 future technologies. 119–20 measurement. 16 Glare. 254 microbial fuel cell (MFC). 119–20 remedy for substandard housing. 257–8 hydrogen storage. 63–4 Evaporative cooling. 248–9 Global warming. 169–70. 119–20 Helican turbine. 16 Information processing. 20–2 Framed construction. 190 Glass. 53 Friedrichshafen CSHPSS system. 260 holographic glazing. 62–3 Flax. 208 Hydroelectric power. 171–4 Heat storage. 172–4 Gulf Stream. 206–7 embodied energy. 208–9 paints. 165–6 Fuel poverty. Sheffield. 259 Insulation. 253–4 molten carbonate fuel cell (MCFC). 19–20 predicted effects. 253–4 alkaline fuel cells (AFC). 90–1. 2–3 Ground source heat pump (GSHP). 49 Evacuated tube solar thermal collectors. 208–9 future technologies. 169–70. 206 Geothermal energy. 70 External environment. 252–3 storage techniques. 187 House Condition Survey. 7–8 Flywheel technology. 187 photochromic. 254 storage.
Leicester de Montfort University. 115–16 Reconstituted materials. 70 Phosphoric acid fuel cell (PAFC). 130 photovoltaic cell applications. 173 Penwith Housing Association case study. 83 energy output. 119 Northumberland Building. 259–60 Photosynthesis. 194 timed control. 189–90 prismatic glazing. 198–9 attention to low profile design details. 15 Masonry construction. 235 International Tokamak Experimental Reactor (ITER). 20. 195–200 air conditioning avoidance. 70 Polystyrene: expanded (EPS). 181–7. 111 Legionella. 197 common architectural problems. Nottingham University. 153. Berlin. 245–6 Maggie Centre. 102 Malaria spread. 204 Regenesys. 204–5 Recycling. 48–9 emissions. Newcastle. 71 organic/synthetic insulants. 258–9 glare. 5 Millennium Galleries. 136–7 planning and site considerations. 191–2 Lighting and Thermal Value of Glazing (LT) Method. Cornwall. 121–2 benefits. 158–60 Molten carbonate fuel cell (MCFC). 72–6 main points. 70 extruded (XPS). 129–37 climate facades. 170–1 copper indium diselenide (CIS). 47–50 geothermal energy. 45–7 277 . 185 Proton exchange membrane fuel cell (PEMFC). 77 range of options. 42–5 tidal energy. 69 technical risks. 207–8 humidity and. 170 Reichstag. Sheffield. 24–5. 6–7 Meltwater lake collapse. 69–70 natural/organic insulants. 82–3 Polyisocyanurate (PIR). 166–9 Mont Cenis Government Training Centre. 197 Oil reserves. 17 Portcullis House. 66 Refrigerants. 45. 193–4 dimming control. 50–1 Office design: design principles. 184–5 conditions for success. 51 Isle of Islay wave power system. 23–4. 164–5 Queen’s Engineering Building. 190 holographic glazing. 198 energy waste. 203–5 reconstituted materials. Dundee. 196 building related illness. 170 Lange turbine. 199 ‘high-tech demand’. 179 Lockheed Corporation. 100–2 National Assembly for Wales. 191. 253–4 Milankovitch cycle. Cornwall. 204–5 refurbished materials. 122 cavity filling. 61 Life-cycle assessment. 77–9 Integrated district environmental design. 194 daylight linked control. 205 Light emitting diodes (LEDs). 165 Photochromic glass. 170 Nuclear power. 127–8 environmental considerations. glass. 256 Photovoltaic (PV) cells. 187 Minerva Tower. 69–70 inorganic/mineral-based insulants. 199–200 inherent inefficiencies. 71–2 materials. 28–30 hydrogen. 85 polycrystalline silicon. 197–8 operational difficulties. 83 commercial buildings. 122 Permanent Insulation Formwork Systems (PIFS). 258–9 Lighting. Germany. 140 Rainwater collection. 203–4 strategy checklist. 150. 6 Methane: biogas. 53–4 Phenolic. 139. 133. 194 localised switching. 235 Polycrystalline silicon cells. 125–6 high and superinsulation. 128–9 passive solar design. 23. 61 Peat bogs. 208 Parasitic energy requirement. 170–1 Montana State Green Laboratory Complex. 133–6. artificial. 70 Population growth. 50–1 nuclear fusion. 192–3 design considerations. 187 switches. 30–41 UK energy picture. 136. 212–13 National Home Energy Rating (NHER). 246 Mosquito aircraft. 80–7 amorphic silicon. 190 future technologies. 66 Photonic technologies. 183 Renewable energy sources. 81–2 Plan-les-Ouates. 16 Meteor strikes. 196 human factor. 198 common engineering problems. 82–3 principle of. 190. 252 biomass and waste utilisation. 18 Microbial fuel cell (MFC). 124–5 case study. 52–3 Mass extinctions. 188–94 atrium. Switzerland. 145–6. 131–3. 187 light pipes. 170–1 problems. 38–9 Jaywick Sands development. 83 cadmium telluride (CdTe). 211 Reflective coatings. 204 reuse. 70–1 transparent materials. 50 solar energy. 182–3. 73–5 Jubilee Campus.INDEX existing housing. 185 photoelectric control. 49–50 hydroelectric generation. 194 occupancy sensing. 172 Refurbished materials. 68–9 health and safety issues. 86–7 heat recovery system. 185 solar shading. 185 light shelves. 149 Prismatic glazing. 26–8 wind power. 130–6 floors and ceilings. 129–30 walls and rainscreens. 194 system management. 17 Pencoys Primary School. 21–2 Paints.
47–8 liquid fuels. Finland. 115. 251 Shape memory alloys (SMAS). 125 Transparent insulation materials (TIMs). 250–1 reducing consumption. 59. 42–5 active solar. 71 Sibelius Hall. Yangtze River. 112–14 Winter Gardens. 243 Wood. 29 Zero-energy House. 64–7 heat reflecting and heat absorbing glazing. 138 unassisted. 133 Solar radiation. 173 Tower blocks: ecological towers. Spain. 205–6 Wind power. 60 direct gain. 87–9 Storms. 103–4 Windows. thermochromic and electrochromic glass. 29 Tidal energy. 48–9 direct combustion. 145–51 natural ventilation. Cornwall. 76 Zion National Park Visitor Center. 129–37. 8–9. 60–2 attached sunspace/conservatory. 64–7 Solar energy. 33–5 potential for the UK. 117 Stirling engine. 98 West Beacon Farm. 98–9 Sea level rise. 7 Vortex water harvesting system. 37–8 tidal barrage. Freiburg. 108–14 types of. 66–7 Windsave. 62–3 Solar House. 43–4 thermal collector types. 45–7 integrated systems. 54–62 active solar thermal systems. 191 System management. 115. 47–9 biogas. 6 Solar shading. 98–103 Toilet: composting. 36 tidal fence. 43 Solairfoil. 116 Tolvaddon Energy Park. 191–2 Tectonic plate movement. 48 Water conservation. 7–8. 102–3 Woking. 63–4 flat plate collector. 44–5 passive solar. 5. 43 solar thermal electricity. 100 Sick building syndrome. 110–14 Wind speed. Sunderland. 209 prospects for. variation. Sheffield. Switzerland. 260–1 Socio-economic factors. 261 Spiral Flugel turbine. 58–60 passive solar design. 115–17 Wave power. 72–6 Swiss Re Insurance Group headquarters. 36–7 wave power. 245–8 Ventilation. 261 Sheep’s wool. 125–6 S-Rotor. Leicestershire. 60 Superinsulation. 239–40 Theatre design. 168 Solar Offices. 42 next generation solar cells. 111 Standby power. 243–4 transport. 111 Saville Garden project. 77. 243 waste. 69–70 Rocky Mountain Institute. 45 solar chimney generator. 5 Thames Barrier. 239–41 planning and regulation. 202–3 Waste utilisation. 54 Sunspaces. Doxford International. 197 Smart fluids. 143–5 Thermal insulation. 38–41 Weald and Downland Conservation Centre. 241–3 procurement. See Insulation Thermochromic glass. 35–6 tidal mill. 71 Sun chart. Utah. 165–6 Solid state phase transformations. 59. 30–41 offshore impoundment. 4 Trombe wall. 62–4 evacuated tube collectors. 239–43 energy services. 33 Thameswey Energy Limited. 156–8 Switches. 254–6 parabolic solar thermal concentrator. 179–80 windows and glazing. 114 Volcanic activity. 214–17 278 . 138–51 internal air flow and. 54–6 commercial buildings. 69 health and safety issues. 15 Whole life costing. 115 Wal-Mart. 261–2 Smart materials. 246 Waste disposal. 98–103 Yangtze River. 246–8 Zuckermann Institute for Connective Environmental Research (ZICER). 77 Tree ring analysis. 245 Roundwood Estate. 140–5 See also Cooling strategies Vermiculite. 65–6 photochromic. 250 Straw. Wadenswil. 209 prospects for. 77 United States. 114–15 small wind turbines. 262–4 SolAir project. increasing severity. 67 Three Gorges scheme. 42 photovoltaic (PV) cells. 154–9 energy efficiency. 114 Solar design. 116–17 flushing of. 31–3 tidal currents. Colorado. 56–8 indirect gain.INDEX Rock wool. Brent. London. 90–1 West Nile fever spread. 38–41 Timber. 70 Vivo building. Three Gorges scheme. 187 Solid oxide fuel cell (SOFC). 138–9 mechanically assisted ventilation.