This House Is Under the Earth and Is Probably Where Smurfs Live

Earth houses are houses built using soil or natural terrain features to help form the walls. Such buildings are partly or completely embedded into the ground.

Architect Peter Vetsch is a major advocate for earth houses, and has built over 90 such homes over the course of his career. One of the main advantage of earth houses is insulation : the thermal inertia of the walls and absence of air leaks makes for naturally energy efficient buildings.