With clever engineering and an elegantly simple design, Diane von Furstenberg reinvigorated women's fashion in the 1970s with the wrap dress. Can she do the same for a building? Her newest project is a 35,000-sq.-ft. office, showroom and retail store in Manhattan's trendy meatpacking district, all heated and cooled by water pumped from deep underground. This geothermal system taps into water that is a relatively stable 55F and transfers that heat to warm the building in the winter and cool it in the summer. The building's roof is covered in easy-to-maintain plants and grasses, and has two heliostat mirrors, which track the sun and direct its rays into the building, reducing the use of artificial lights during the day. Who says being environmentally conscious can't be cool—and hot?