Lu half a foot, look up or down.

Yang Zhai looks up and Yin Zhai looks down. And Lu's half-foot view of the top or the bottom is divided according to the specific things built. If you are building a villa, you are looking at the top, and vice versa. Lu Banchi, also known as "Lu Banchi" and "Lu Banchi", is a measuring tool used in building houses, similar to the ruler used by craftsmen today.