We may not be aware of it, but ordinary family homes in the U.S. and the rest of the world are not energy-efficient. Most of their energy goes to heating and cooling, and a lot of it is wasted, as warm air and cool air escape through fireplace chimneys and thin or poorly fitting windows and doors. A passive house loses almost none."Imagine a thermos ,"said housing developer Brendan O'Neill."You have insulation  everywhere, and it's basically completely sealed. And so the idea is to build a house like a thermos. So the windows are sealed. There's insulation completely surrounding the building. We make it as sealed as possible." A 147-square-meter passive house, presented by O'Neill Development Corp. as a demonstration unit just outside Washington, was brought to the site in two boxes."Once it's set and put together, it takes about four weeks to complete the outside construction, to put down carpets,"O'Neill said."If everything is set in place, you put a house like this together in about four months."The total cost of building it was $325,000, or about 17 percent more than constructing an ordinary house. But its utility  bill is only around $20 monthly, or one-tenth the amount for the average house of the same size. While passive houses have been around for a long time, the idea has never taken root in the U.S. There was no driving force to push it. However, David Peabody, an architect who designs passive houses said,"I think climate change is now becoming a larger issue. And I think building standards are catching on to that. So people are becoming more aware of energy."Peabody said the cost of building passive houses could come down."What really makes sense for truly affordable housing,"he said,"is to build multi-storey buildings." What is the feature of a passive house?
There're no windows or chimneys. There's little space to place furniture. Its building cost is  ly high. It takes about four weeks to build one.