It's simply not true. In fact, recent studies show that people think the cost of building green is three times more than it really is! Such overestimates cause slow adoption by builders of good, affordable green-building practices.

Sure, some things (take onsite renewable energy, like solar) cost more. But loads of anecdotal evidence, theoretical modeling, and real life data, such as a study done by green consultants Davis Langdon Adamson, show that green buildings don't have to cost more in theory and usually don't in reality. The US Green Building Council has done numerous studies that have shown that the increased cost in meeting LEED standards is between zero and 3 percent.

Unfortunately, there's just not enough good, consolidated and well-analyzed data about the real cost (and performance, for that matter) of residential green buildings, as there is about commercial green buildings.

I'd like to see builders submit real cost data on their homes as part of the requirements of the new LEED for Homes Program, or any number of other green building initiatives in the country. Anyone involved in the green building industry knows that green doesn't have to cost more, but it's hard to convince people without good data to backing you up.

What has been your experience building green homes? Have you done so with minimal additional cost? Have you backed away from it because you thought you couldn't sell it? I'd like to hear your own story about it. Let me know how you deal with this myth.