I have tried, with each house I've ever owned (Portland, Joseph, Ashland in-town, Ashland out-of-town), to move them toward greater efficiency of the use of water, energy and materials. Of course, the only environmentally pure act a human can take on this Earth is suicide (of course, in a green way where one's body is fully recycled). But until then, I try to make my personal habitats have a lighter footprint.
If you are not doing it yourself, you need find a builder is very experienced in green building. Alas, most builders are not, so you may have to settle for one that is willing to learn and work with you. This means you need to become expert enough in how to build green so that your builder (and perhaps also your designer if it is a large project) will be able to meet your needs.
If you live near Ashland, OR, the builder of my out-of-town habitat (aka Sunny Oaks) was John Fields of Golden-Fields Construction and Design, whom I most highly recommend. John knows his stuff and was willing to work with my particular ideas. He also wasn't afraid to tell me when of an idea of mine sucked, but he always had a better alternative.
My magnum opus of green building (so far) is my home outside of Ashland. The Path to Greener Buildings, published in Home Power magazine, is about the trials and tribulations of building a state-of-the-art, super-insulated, passive- and active-solar, toxic-free and earth-, people- and pet-friendly habitat that is Sunny Oaks.
Building Green and Green Building Advisor are content-rich in all the basics, details and leading edges of green building. Some of the content is free, but go you deep, you're going to have to pay. Considering what you'll be spending building or remodeling, the subscription are a small price to pay. I have found them invaluable.
Joe Lstiburek of Building Science Corporation has published several books, which I highly recommend, in their "Builder's Guide" series (Cold Climates, Hot-Dry & Mixed-Dry Climates, Hot-Humid Climates and Mixed-Humid Climates). To determine which book is best for you, you need to determine your hydrothermal zone. Joe's builder's guide series is published by the Energy and Environmental Building Alliance.
[I'm working on it.]