Is it permissible to consecrate a room and a bathroom from a house inherited by Muslims as a waqf, and do the kitchen and the courtyard enter into the waqf, despite being in one deed?

If a person passes away leaving behind one full sister and three sons of a full brother, and no other heirs, then the full sister receives one-half as a prescribed share (fard), and the remainder goes to the sons of the full brother by way of residuary inheritance (ta'sib). The inheritance is divided into six shares: the sister receives three shares, and each son of the brother receives one share.

As for his will to the Muslims for a room and a bathroom from his house, this is a valid will that takes effect for non-heirs, and it is executed within the limits of one-third of the estate. If the value of the room and bathroom exceeds one-third, the excess portion is not executed unless the heirs consent to it. Otherwise, one-third will become a communal share for the Muslims, and two-thirds will go to the heirs. This matter must be presented directly to scholars or a Sharia (definition) court for confirmation.