This is a bit off-topic for this blog, but I thought readers might want to hear about houses that reduce energy consumption by 90 percent. According to Studio 804, which built a passive house in Kansas City,
The heating load is drastically reduced by means of a super-insulated, virtually airtight building shell, broad Southern exposure and an energy recovery ventilator that provides constant fresh air and even distribution of heat.
The house is being sold for about $180,000, which puts it out of reach of the poorer residents of Kansas City. They are the people who need these homes the most. We need some kind of partnership, a la Habitat for Humanity, that pairs rich people willing to pay for these homes with poor people who need a more efficient home.
For more articles about passive homes, go to a blog called Jetson Green, which has published quite a few articles on passive houses in the United States. There are links to those articles at the end of the post on the KC house.