In some cases, owners may only enjoy 70% of the property rights, which means that they have certain restrictions on the use and disposal of houses. The transaction and transfer of such houses may be restricted, because the remaining property rights belong to units or collectives, and they may enjoy the preemptive right or veto power.
It should be noted that the specific policies and regulations of small property houses may vary from region to region and unit. You can consult the relevant policy documents or consult the local real estate management department for more information.