There's a guy in Maryland who opens his house to tours - a friend who lives in DC went on it. He has an incredibly efficient house. I believe during the winter, he actually puts electricity back on the grid and gets paid for it. The centerpiece of his home is a corn stove which heats the house more efficiently - or at least cheaper - than gas. Solar panels of course. The heat from his runoff water - like in the shower - helps heat the incoming water, etc.