Most people will choose to build three walls or four walls according to their own housing situation and personal wishes. When building a fence, it is best not to pursue individuality, nor to build a fence with one side high and one side low in order to save materials, or the heights of several walls are not uniform. This type of fence will destroy the feng shui of the whole house. The house is neat, one-to-one and symmetrical. If the height of the fence changes, it will affect the whole pattern.