What does it mean that the opposite room is always shut in the dark in broad daylight?

It may be that the owner prefers the dark environment, or it may be that the owner works during the day.

A house is a building built by people to live in. Generally, there are walls and roofs, and rooms are separated inside, but they don't need to be separated. The house is the mother of the family and the sustenance of human existence. It can avoid all external interference, resist all kinds of weather changes and enjoy a comfortable life with relatives. Generally speaking, it refers to a permanent place with a roof, surrounded by walls for people to work, live, study, entertain and store materials, with a fixed foundation and a height of more than 2.2 meters. However, according to the living habits of houses in some places, caves and bamboo houses where people can live all the year round should also be included.