Siheyuan' in Chinese, 'Si' means 'Four', which here refers to the four sides: east, west, north and south. 'He' refers to the surrounding, meaning the four sides circle into a square.
A Si he yuan is normally constructed on a north-south axis facing south. The principal rooms are located to the north while those to the east and west are referred to as 'wing rooms'. Those on the south are called dao zuo, which means 'revered rooms'.