The ruling on building mosques under houses

Question:
Following this, a message was received by the program from Jeddah, sent by a listener who says: The sender, A.M., a resident of Jeddah, asks and says: What is the ruling on building mosques under houses? And is it permissible to pray the Friday prayer and congregational prayers in them? What is the ruling, and what is the ruling on this action? May Allah reward you with good. What do you say about that?

Answer:
As long as the mosques are pure in themselves and prepared for the worshippers, there is nothing wrong with that, even if there are houses above them, or if they are above the houses, especially when there is a need for it, such as when the area is narrow and the buildings are crowded. There is no harm in making the side floor a mosque, or the upper floor of a building a mosque, and preparing it for the worshippers; there is no blame in that, and praise be to Allah. However, it is easier and better to allocate the mosque to an independent building with its facilities and expansions, as that is more beautiful and more complete. May Allah reward you with good and do you good.