Wholeweal?

Lifestyles TopTenz has a thoroughly interesting list of experimental towns and communes from around the world, including Scotland's Findhorn:

"Scotland’s Findhorn Ecovillage is perhaps the most notable example of a community founded on principles of environmental sustainability and renewable energy. The commune was started in the 1960s, but it didn’t take on its current form until 1982, when residents made a concerted effort to show that an environmentally unobtrusive community could flourish both socially and economically. The village still exists today, and has been noted as having the smallest environmental footprint of any town in the modern world. This is thanks to an ecologically friendly building code that encourages the use of found materials—several houses are built from recycled whiskey barrels— along with wind turbines and a water treatment apparatus called the “Living Machine,” which makes use of algae, snails, and plant life to purify the community’s water supply."

Findhorn's official website is here, and includes specifications for building your own eco-home.