Must the owner of the lower floor rebuild the lower walls if the upper floor owner demands it after the walls collapsed?
General Chapter
Al-Mughni
Book of Settlement
Primary text
There are two narrations concerning the obligation of the lower floor owner to rebuild the lower walls upon the demand of the upper floor owner. According to one narration, he is compelled to do so. This is the position of Malik, Abu Thawr, and one position of Al-Shafi'i. Under this narration, he is compelled to rebuild the structure alone because the walls are his exclusive property. According to the second narration, he is not compelled. This is the position of Abu Hanifa.
Supporting text
In both narrations, if the upper floor owner rebuilds the walls using materials provided by himself, the lower floor owner cannot benefit from them until he pays the value, potentially meaning the upper owner cannot reside there. This aligns with Abu Hanifa's view, as the house is built for residence and the lower owner has not acquired ownership of the new structure. Alternatively, it is understood that the benefit pertains only to specific uses, like securing wood or attaching pegs, allowing the upper owner residence without full proprietary rights over the wall itself, which is the view of Al-Shafi'i, likening it to seeking shade from the outside.