Tenants are generally responsible for maintaining a rented property and ensuring that it is restored to the state in which it was in at the beginning of the lease. Any repairs which are required are called 'dilapidations' and these should be specified in the lease. In general, any responsibilities which are not specified in the lease will fall to the tenant.
The full scope of tenants' obligations for dilapidations will often depend on the type of property and the length of the lease. Many commercial premises are let on a full repairing and insuring (FRI) basis, which means the tenant takes on both repair and insurance costs.