This tree house uses geothermal power, too. Nice, but a bit too expensive, I think.
''The jury really liked the Tree House,'' Ms. Nadel said. ''It is very distinct in how it blends in with the environment -- there is nothing like it.''
The four-story 38-foot-high residence rises from a fern-carpeted ravine to a dense canopy of leaves. Set on two acres in Cold Spring Harbor, the approximately $350,000 house will be the home of ''a bachelor who had a house on the adjoining property but now wants to move into a natural lifestyle,'' according to Eduardo LaCroze, the principal of the company's Long Island office.
Each floor of the house is 20 by 20 feet. The first two floors, which include the garage, entrance and utility rooms on the first level and the kitchen and living room on the second, have a bluestone exterior and are built into the natural slope of the ravine. The third level contains the guest quarters, including a bedroom and bath; and, the fourth includes the master suite and a penthouse deck. The upper two levels are wrapped in copper. The house is heated and cooled with geothermal energy, which is ''highly efficient, heating and cooling the house through an exchange of the hot and cold energy contained in the soil,'' Mr. LaCroze said.
''The building was conceived as a tree,'' with a green top and a weathered lower section, he said. ''Down the road, the copper will turn green and the bluestone will weather, and the house will melt into the slope and be camouflaged into the densely wooded site.''
http://www.nytimes.com/2001/12/02/realestate/in-the-region-long-island-courthouse-and-tree-house-win-architects-awards.html?pagewanted=2