"In years past, green construction accounted for only a fraction of new construction. Now, the green market is expanding into the mainstream and may well surpass traditional construction within a decade. Successful green buildings are providing models for others to duplicate, and the growing market for environmentally responsible products is making it easier for architects to specify green materials.
...What makes a home green? Like everything in real estate, it is all about location, because it is nearly impossible to build a green home amid suburban sprawl. Some homes in sprawling developments may provide a healthier living environment and be more efficient than others, but few are likely to be truly green because more energy will be consumed traveling to and from the home, and sitting in traffic, than can be saved through energy efficiency in the home."
Thanks to Urban Land Institute