Is it permissible to donate an entire residential apartment as an endowment (Sadaqa Jariyah) in a will instead of distributing it among the heirs according to Sharia?

It is permissible for a person to donate all of his wealth during his lifetime or to make it an endowment (waqf). However, a will (wasiyya) is not permissible except within the limit of one-third. The difference between an endowment and a will is that an endowment is an immediate contract that takes effect at once, whereas a will takes effect after death, and only what is within the one-third limit is executed from it. Anything exceeding that, or if it is for an heir, requires the consent of the heirs. It is preferable not to make a will if the wealth is little and the heirs need it, based on the saying of the Prophet, peace and blessings be upon him: "It is better for you to leave your heirs wealthy than to leave them poor, begging from people."