As noted, building an eco-friendly home won't be cheap, although the costs vary. "It really depends on the geographic region," says Woods. "California can range from $150 to $250 per square foot. My house [in Georgia] was $75 per square foot."
If you can't find an eco-home, you can always add features to an existing house, although that won't be inexpensive, either. According to a recent issue of Sierra, the Sierra Club's magazine, the average rooftop solar array in the United States costs about $20,000, although federal and state tax credits can bring that number down significantly.
And if you can't afford to build and can't find a home that makes you feel you're doing something worthy for the environment, take heart that you may still end up doing a lot of good with the house you buy. After all, if you purchase a small home instead of a large house with extra rooms you don't need and high ceilings, you'll use fewer natural resources for your energy than the homeowner who lives large.
Furthermore, keep in mind that if you are building a sustainable home, no matter how environmentally friendly the building materials are, there's almost always a negative cost to the environment when building anything. (Those environmentally friendly materials have to be transported by train, truck or something that uses gas.)
Surreal as it may sound, homeowners who buy a house that's already been lived in are being better stewards of the environment—at least in the short term—than the environmentally conscious homeowner who builds a new sustainable home from scratch.