For a specific single functional room, the feng shui ratio of width to depth is 1.5: 1. If the depth is too large and the width is too small, the room will be dark because of the lighting and ventilation in the metropolitan area. If the depth is too small and the width is too large, it is not conducive to room insulation and wastes resources. The founder of the apartment means that the width and depth ratio of the apartment should be reasonable to achieve the balance of lighting, ventilation and heat preservation.