One of the most radical solutions in the field of shelter is represented by the underground towns and villages in the Chinese loess belts. Loess is silt, transported and deposited by the wind. Because of its great softness and high porosity, it can be easily carved. In places, roads have been cut as much as 40 feet deep into the original level by the action of wheels. In the provinces of Honnan, Shansi, Shensi, and Kansu about ten million people live in dwellings hollowed out from loess.
The dark squares in the flat landscape are pits an eighth of an acre in area, or about the size of a tennis court. Their vertical sides are 25 to 30 feet high. L-shaped staircases lead to the apartments below who rooms are about 30 feet deep and 15 feet wide, and measure about 15 feet to the top of the vaulted ceiling. They are lighted and aired by openings that give onto the courtyard.
From the top one can only see small trees placed carefully above each staircase that leads downward. The tree acts as the official sign of the house, so you don’t describe your house to visitors or give a house number but tell them about your tree.
Architecture Without Architects // Bernard Rudofsky