Its gate is usually at the southeastern corner according to the Taoist thinking. Normally there is a screen-wall inside the gate so that outsiders can not see directly into the courtyard and it is also believed to protect the houses from evil spirits. Outside the gate of some large siheyuan, there are a pair of stone lions on each side.
The gate doors are usually painted vermilion and have large copper door rings. Usually a whole family lives in compound. The elder generation live in the main house, the younger generation live in the side houses, and the south house is usually their sitting room or study.
All the houses have large windows at the front and small windows high up in the back walls. Some houses do not even have back windows. Some large compounds have two or more courtyards, inhabited by a big traditional extended family with several generations.
Since housing is one of the most difficult problems in a large city like Beijing, the siheyuan is now often lived in by several families and large parts of the courtyard have been taken over by each family to build kitchens or additional rooms and storage places.
There are still some nice siheyuan in Beijing, mainly former mansions of princes, some of which have been turned into museums, and others are lived in by high officials or used as government offices.
