A Japanese architecture firm has come up with a neat idea for eco-friendly teahouses — it has little compartments in the surrounding wall that can generate heat via compost, so you don't get cold when you're sitting inside. The best thing about it might be its name: Comploo. From Inhabitat:
To feed the composter, garden waste, food scraps or other compost materials can be dropped in through a door at the top of each bin. A system of sealed ducts runs through each of the bins, and as the air circulates within the walls, the decaying compost warms it. This heated air is in turn emitted through a central vent that releases into the structure's interior. Occupants can comfortably sit along a circular bench surrounding the heat source, and enjoy the ambient natural light permeating through the transparent dome roof above.