According to the Measures for Housing Registration of the Ministry of Construction, houses on collective land are registered with buildings as the basic unit, and houses on state-owned land are registered with rooms as the minimum basic unit. Therefore, the latter can handle the registration of separation or merger.
The loan period cannot be changed, let alone sold and transferred, and can only be done after the loan is paid off. Because when you sell, you have to provide the corresponding documents and property certificates, and the documents you can provide are still original, which cannot be separated from the bank. You can only go through the next procedure if the bank agrees. Under normal circumstances, the bank will not agree.
Only if you rent it to others privately and charge a certain rent, you can consult the window of the Housing and Construction Bureau of the government service center in your jurisdiction, and they will give you a reasonable answer.
Good wishes!