Is it permissible to sell the land of a father afflicted with Alzheimer's and confined to a wheelchair in order to pay off his debt, give charity on his behalf, and build additional floors in the house, without distributing the money among the heirs?

The matter must be referred to the Sharia (definition) Court to rule on whether or not the father should be interdicted. His wealth must be preserved until the ruling is issued. If the court rules that he is competent, then his permission is required to dispose of his wealth. If it rules that he is interdicted, then the guardian may not dispose of the wealth except in a manner that is most beneficial to him. Therefore, charity and gifts without compensation from his wealth are not permissible. As for settling his debts, this is a necessary matter, and nothing from his land or real estate should be sold for this purpose unless it is more beneficial for him or it is impossible to settle the debt otherwise.