While home sales may be sluggish in many parts of the country, more buyers are placing an emphasis on green -- with some studies showing that green homes can sell for higher dollar than non-green homes. In Portland, Ore., an analysis from the Earth Advantage Institute found that green-certified new homes sold, on average, for 8 percent more than non-certified green homes--and in one of the counties included in the study even more than 23 percent higher. Earth Advantage Instit