8. The tenant under a private tenancy–
(a)shall take proper care of the premises comprised in that tenancy as a good tenant;
(b)shall make good any damage to those premises wilfully or negligently done or caused to the premises by the tenant, by any tenant of his or by any other person lawfully living in or lawfully visiting the premises;
(c)shall keep the interior of the dwelling-house in reasonable decorative order; and
(d)shall not carry out any alterations to those premises without the consent of the landlord, but that consent shall not be unreasonably withheld.