Is it illegal to rent in a duplex group?

Strictly speaking, group rent is illegal and against the regulations.

Group rent is to divide the house into several small rooms and rent them by room or bed by changing the structure and plane layout of the house.

Illegal basis for group renting: The Measures for the Administration of Rental of Commercial Houses stipulates that if a house is rented, the originally designed room shall be the smallest rental unit, and the per capita rental building area shall not be lower than the minimum standard set by the local people's government. Kitchen, bathroom, balcony and underground storage room shall not be rented for people to live in. During the term of the house lease contract, the lessor shall not unilaterally raise the rent level at will.