Is it a crime to convert my berth into a hotel without the consent of the householder?

He is guilty of modifying other people's shops without the consent of the household head. Such people will certainly need to bear relevant legal responsibilities.

Since the shop has been sold to the owner, the ownership of the shop should belong to the owner. If other people need to make corresponding renovations to the shop, they must first discuss with the owner before the renovation. Negotiable.

Carrying out modifications privately without the permission of the owner completely infringes on the rights of the owner. Therefore, as the owner, you should first negotiate with the parties concerned to see if the two parties can resolve the matter through negotiation. If not, then I can only see him in court.