Is it permissible, Islamically, for the paternal uncle to demand the return of the house that the father has owned since 1982, especially given that all relatives and neighbors are aware of the father's ownership, and that the father supports his sister and does not possess the means to purchase new housing?

The judgment regarding the ownership of the house, claimed by either the father or the uncle, should be referred to a judge. A ruling cannot be made without reviewing evidence and witnesses. If the uncle owns the floor where the father resides, he is lawfully permitted to request the evacuation of the dwelling, especially for the purpose of renovation. However, it is more fitting that he treat his elder brother with respect and kindness. It is advisable to consult with the uncle to maintain family cohesion, and to treat him with kindness, dutifulness, and respect.