It's possible to build a house that doesn't need any source of heat besides the sun and the warm bodies inside. Even in frigid Vermont.
Barbara and Steven Landau are building a house in Vermont—a handsome, three-bedroom, timber-framed 2,000-square-foot house—with neither a furnace nor any heat source. Again, this is in Vermont, where winters are long, dark, and frigid. The New York Times has their story, and this great video of the Landau's house under construction.