Family building is not a legal type of real estate. Whether the family building has property rights can be bought and sold, and it cannot be generalized. It is necessary to consult the specific unit. For example, the family building of the army belongs to the state; Family members of railway departments belong to policy welfare houses.
The certificate of ownership of the house is the only legal proof that the right holder has the ownership of the house according to law and exercises the right to possess, use, benefit and dispose of the house. Housing rights registered according to law are protected by state laws. In other words, only having a personal real estate license can prove that the house is your own, not just the right to use it.