The property company unilaterally decided to lease the basement of building 1 to small vendors to operate small supermarkets.

This depends on whether the developer will hand over the garage part. If it is handed over, it will be owned by all owners. If it is not handed over, whoever builds the underground part will have the priority to use it.

If it is shared by all owners, the basement shall be disposed of by all owners. If it is owned by the developer, the purpose of the basement should conform to the purpose of the basement and cannot be changed.

So the proceeds from the basement will go to the people who have the right to use it. Property can only extract the corresponding proportion of remuneration on the basis of income, and the other part can be used for the renovation and maintenance of residential areas.