The Ba Zhai system is based on the relationship of the individual with his space.
We determine the East or West group and the distribution of the favourable and unfavourable energies of the habitat (Trigram of the 8 Demeures).
In the same way one determines the East or West group of the individual (Ming Gua).
Formula of the Trigram of the 8 Demeures:
The Gua of the house is calculated according to the cardinal direction of the longest and least open wall (Back or Sitting), opposite the brightest façade (Front or Facing).