Why do people living in Saudi Arabia live in houses with small flat windows?

Because Saudi Arabia is located in a tropical desert climate, it has high temperature and little rain all year round. Because of the scarcity of local precipitation, there is no need to consider drainage in roof design, so the roofs of local traditional houses are all built with flat roofs, which is conducive to collecting rainwater. Because of the high local temperature, the walls of their traditional houses are thick, which is beneficial to heat insulation and prevent hot air from entering, so as to keep the houses cool and enjoy the cool. Because of the vast and windy weather in the desert area, their traditional houses have small windows to prevent the invasion of sandstorms.