Courtney,
I am surprised 308 people read your post and nobody tried to answer your question. I know your post is old, but maybe you will get this reply.
"Green Building" is the practice of home builders of building extremely energy efficient homes and using environmentally responsible building techniques and materials. It would take several pages to explain in detail. Please feel free to go to the web pages below which explain in more detail about green building. They also have many links that will help you become educated about what you can do to make your home more "green".
http://www.mvhomebuilders.com/Green_Building.phphttp://www.mvhomebuilders.com