A good green builder is not on the endangered species list, it just feels that way sometimes. Finding a good builder requires a little effort, but it will save you lots of money in the long run. Do some preliminary research about what house features are important to you. Make a list and separate it into two parts: must haves and would be nice to haves. Then you can start interviewing builders. Yes, you read correctly, it's time to interview builders. Early.
Creating a team (builder, designer, homeowner, etc.) can also lower costs. In the very early stages of our home design, there was a discussion between the designer and builder about the roof line. Both knew that we would be adding solar and they discussed the best way to angle the roof so that we could get maximum solar benefit. Having the builder involved early meant that we could tweak the design before the final plans were drawn. It saved a lot of time and money.
A good green builder is familiar with green practices and knows how to integrate them into a home. Incorporating passive solar, thermal envelope, and so forth should be second nature to your builder. He should be helping you to add green and value to your plans. If every green suggestion you make is met with “it's going to cost you”, you might want to think about finding another builder.
When you're interviewing builders, be sure they can communicate well with you and your designer. Do they understand what you want and do they know how to achieve it? If you start mentioning things like spray foam insulation, metal roof or thermal envelope and their eyes glaze over, run, don't walk away from them! A good green builder understands green practices and is willing to talk to you about them.
When my husband and I were interviewing builders, we talked about wanting to do a geothermal heating and cooling system. One builder was not sure that it was a good idea. He knew we were on a tight budget and geothermal (especially here in Texas) is expensive to install. At that time, he felt it was too expensive and that it would get cheaper later on when there were more installers. However, once he saw that we were adamant about it, he included it in the estimate. He ended up being our builder and got us a good price on the geothermal installation. He helped us find other ways to cut costs and stay on budget. We were impressed with his “green” knowledge, his ability to listen, and the fact that we got the house we wanted built on budget!