Whether or not your tenant is allowed to use the commercial rental as a residence from time to time is best addressed in the written lease agreement that you have with him or her in that the document sets forth the obligations owed to you as the landlord by the tenant and vice versa in the absence of conflicting state law. If your lease prohibits such use as a residence from time to time, then it is not allowed.As to any zoning requirements prohibiting the commercial space as a residence from time to time, you would have to make a further inquiry into the local permit and resource department where the commercial building is located.From a practical matter, an occasional overnight use of the commercial space for sleeping especially when one is tired and cannot drive home should not be deemed a situation for a reprimand for the tenant.