It is a frequently used formula for determining the compatibility of you and your house or office. You can use the formula’s results to calculate your Kua number and your four auspicious and four unfavorable directions.

The Eight Mansion correspond to the eight home kinds and the eight Life Kua (Life star) numbers.
Feng Shui’s Eight Mansions originated with Bagua (the eight trigrams). Each house can be divided into eight directions, and each chart contains eight stars. Each chart has a unique arrangement of the stars, but there are two distinct groups: East and West.
The East and the West are two distinct groupings.
The four fortunate directions in the East group charts are always in the south, southeast, east, and northeast. The charts for the West group depict the fortunate directions in the polar opposite directions (Southwest, West, Northwest, and Northeast).