Environmentalist Donnachadh McCarthy has helped persuade his local council in south London to ensure all new buildings include rain catching devices to preserve water.
By Alison Freeman
BBC News Online, London
Having championed the green lifestyle from his solar-powered cottage in Camberwell for the past 12 years he has now written a guide to eco-friendly living called "Saving the Planet Without Costing the Earth".
The first steps towards leading a greener lifestyle
BBC News Online's Alison Freeman spent seven days using the book to see if she was an eco-warrior or an eco-wimp.
First off, I'm into the shower - a green tick for that, as the average three-minute shower uses just 30 litres of water where as a bath takes between 80 and 200 litres. I gloss over the fact my shower lasts three-times that length.
My teeth-cleaning habits are also approved as I already turn the tap off while brushing, which not only saves water but money too as our water supply is metered.
I fall down on most of my personal hygiene products as the only natural ones I use are my shower gel and body lotion. The rest - shampoo, conditioner and toothpaste - are regular brand names with chemicals in them.
TIPS ON BEING GREEN
Always turn the tap off while brushing your teeth
Take a shower instead of a bath
Re-use plastic bags and refuse one if you can
Buy organic food and wine
Buy recycled toilet roll and paper
I head off to work by public transport - another green tick - but I lose points grabbing a takeaway lunch packed in landfill-clogging plastic.
I decide not to use the extra napkins I am given as toilet roll, which is what Mr McCarthy suggests in his book, as my boyfriend will not even entertain using a supermarket's own brand. So instead I leave them in a pile on the desk for future use.
My conscience is eased by re-using the plastic bag my lunch came in at the supermarket - despite the strange look from the girl behind the counter.
The book says to use cotton hankies instead of paper tissues, but I have a terrible cold and I have to admit the idea of washing lots of blown-on hankies is not appealing.
I do however decide to take some more direct action and sign-up for a service which stops junk mail being sent to your home. It only takes a few minutes and I smugly tick the box which says I am asking for junk mail not to be sent to my house for "environmental reasons".
My homemade packed lunch is in a re-usable plastic box and I eat with a fork from home.
I also start using my own mug for tea and coffee at work instead of disposable ones.
I have always felt guilty about throwing plastic bags away and have a large collection in a kitchen drawer. I decide to pop a couple into my bag for when I go shopping.
I notice that I am becoming obsessed with re-using plastic bags but some of the more adventurous ideas are not possible for me because a) I do not have a garden and b) I do not own my own home.
Who thought recycling would be so satisfying?
However our spider plants help to absorb chemical pollutants in the air.
And I let out a triumphant whoop when, for the first time on rubbish day, our weekly recycling bag is twice the size of our un-recyclable sack.
My digital camera gets another green tick as it avoids the use of chemicals in a traditional camera's film development and saves paper by cutting out unwanted prints.
Mr McCarthy tells me that as I am about to buy a house it is the perfect time to look at how to make our lifestyles more green.
We have plans for a compost heap and are considering a water harvester.
Feeling positive about my green abilities, I decide to look into buying toothbrushes with detachable heads. By simply adding a new head to the re-useable handle it substantially cuts down on waste.
The website sells them at quite a reasonable price. But just as I am about to buy two handles, plus a couple of packs of heads, I notice the delivery charge is almost £4. This is almost of half of the cost so I decide not to buy them for now and think about it.
Instead of getting a brand new envelope to send a report to our solicitor I decide to recycle one we have received.
I skilfully tape small pieces of paper over the frank marks and address window. My boyfriend ends up hand-delivering it and claims he virtually sprinted out of the office, embarrassed by the slap-dash nature of my handy work.
I am off to visit some friends this evening and decide to buy some organic wine.
It was time to test the "less chemicals, smaller hangover" theory
The shop is a bit out of my way but when I arrive it is a veritable Aladdin's cave of organic items. Everything from ready-made sandwiches to organic meat, as well as a good selection of wines and lagers.
Some organic wine drinkers claim it gives you a smaller hangover - another good reason to try it!
I plump for a Pinot Grigio at £5.99 and a couple of bottles of lager which are priced at about £2 for 500ml and some natural toothpaste.
The Pinot goes down a treat - I cannot taste a difference between it and the non-organic I usually drink - and it costs about the same.
The local supermarket does stock organic wine and I see all their price tags are marked differently so they are easier to find. No Pinot but there are about four or five different white wines - prices ranging from £4.99 to about £8.
Environmentally friendly washing-up liquid proved a success
I am delighted to see biodegradable washing-up liquid and recycled toilet paper are also in stock and the prices are similar, and sometimes less, than the known brands I usually buy.
The proof of the pudding will be in the eating though.
But I am optimistic if the natural toothpaste is anything to go by. It foams-up well and although the flavour is not as strong as my usual non-natural brand, it tastes good and still leaves me feeling fresh. I am delighted to say I am a convert.
My partner tries the organic lager I bought and says it tastes good but points out that six would cost more than double the price of the regular brand which is on offer at our local off-licence.
Reading through the book on the final day I am able to give myself a pat on the back for a few other energy-saving things I already do.
I only boil enough water for the number of cups of tea I make, only use the washing machine when I have a full load and my allergy to the ironing board is justified as my under-used steam iron is an energy guzzler.
And the natural washing up liquid is effective so I vow to start replacing the brands I use for many household chores with environmentally friendly makes.
I realise that many of my day-to-day habits are already a small step towards living a green lifestyle and with a little thought it is not hard to make a small difference.
I may not be an eco-warrior but I will certainly keep trying to be a friend of the earth.