Ancient architecture of the scale of each building proportion to follow what principle

China's ancient architecture of the plane to rectangular for the most common, a rectangular building, there are two scales on the plane, that is, its width and depth. Where the long side is wide and the short side is deep. For example, a three-room north house, it is wide in the east-west direction and deep in the north-south direction. Monolithic buildings are made up of the most basic unit, the "room". Every four pillars around a room, a wide for the "face width", also known as "face width", deep for the "depth". The sum of a number of single face width of a building composed of a total face width, known as "through the face width"; a number of single depth is composed of a single building through the depth.