Whether the basement can be recognized as a commercial house depends on whether it has legal property rights. Some basements have separate property rights and can be bought and sold freely, so they can be classified as commercial houses. The basement, signed as an annex to the contract, is also a property right, and it is a commercial house. Only the main house can be used as an accessory for trading. All commercial housing is to sign a commercial housing sales contract under the Housing Authority system.

Basements and underground garages in many communities have no property rights, and they do not sign commercial housing sales contracts as affiliated houses. The owner buys the right to use from the developer. However, this situation is difficult to define, because according to the provisions of the Property Law, this kind of similar property ownership belongs to all residents of the community and does not belong to developers. It's just that now the national conditions are like this, and everyone acquiesces.