Why are all the houses in the north half crypt buildings?

Semi-crypt architecture is the architectural style of northern minorities, and the earliest semi-crypt architecture appeared in Banpo site. The northern region is cold and dry, and this kind of building is conducive to cold and warmth, similar to the current caves. Part of it goes deep underground, which is not only warm in winter but cool in summer, but also can resist the invasion of wild animals.

Banpo settlement, about 5000 ~ 6000 years ago, is located in the residential area of banpo village, Xi City, Shaanxi Province, in the Yellow River valley. It has a big rectangular house, where clan members can move together. There are many small round or square houses around, which are the residences of clan members. There are trenches around the residential area to protect it.

Most of the houses where Banpo residents live are semi-crypts. They first dug a square or round hole from the surface, buried pillars in the hole, then tied branches along the hole wall to form a fence, smeared grass mud inside and outside, and finally erected the roof. The floor of the house is very flat, with a pit in the middle, which is used for cooking, heating and lighting. The sleeping place is higher than the ground.