mathoda.com

It captures and uses rainwater, heats water and runs it under the floors to heat the house, filters and reuses sink and shower water, has a living roof that insulates the roof, runs mostly on solar power, uses bars of led lighting to light the house, and has double paned glass walls:

http://www.livinghomes.us/

Here’s a non pre-fab eco friendly home for comparison, Idea House in San Francisco’s Mission District:

http://www.sunset.com/sunset/home/article/0,20633,1666702,00.html