Since ancient times, the number 4 has been considered unlucky, so it is forbidden to open four doors in the house. After all, the homophonic "death" of 4 is very unlucky, and generally everyone will avoid the four doors.
2. Five doors
From the perspective of geomantic omen, it is best to have an even number of indoor doors, including all doors. Some people are even more afraid of five doors, because there is a saying that "the noon gate will be cut."