Unfortunately there is no clear definition of a "green built home" yet. Energy Star for example is a marketing idea, not necessarily a green idea.
Standards for green homes might include direction, instant hot water, lighting, solar panels, min AC SEER rating, min insulation rating, construction materials such as bamboo, insulation types such as foam vs blow, radiant barriers, etc. How about yards....should they be xeriscape?
I see very few homes built in what I consider really green fashion and in many ways they are not green at all.