(1)Except as otherwise provided by the following provisions of this Part of this Act, where the rent payable for any statutory period of a regulated tenancy of a dwelling-house would exceed the rent recoverable for the last contractual period thereof, the amount of the excess shall, notwithstanding anything in any agreement, be irrecoverable from the tenant.
(2)Subject to section 49(5) below where a rent for the dwelling-house is registered under Part V of this Act the following provisions shall apply with respect to the rent for any statutory period of a regulated tenancy of the dwelling-house, that is to say—
(a)if the rent payable for any statutory period would exceed the rent so registered, the amount of the excess shall, notwithstanding anything in any agreement, be irrecoverable from the tenant; and
(b)if the rent payable for any statutory period would be less than the rent so registered, it may, subject to section 33 below, be increased up to the amount of that rent by a notice of increase served by the landlord on the tenant and specifying the date (which may be any date during a rental period) from which the increase is to take effect.
(3)The date specified in a notice of increase under subsection (2)(b) above shall not be earlier than die date from which the registration of the rent took effect nor earlier than four weeks before the service of the notice.
(4)Where no rent for the dwelling-house is registered under Part V of this Act the provisions of sections 30 and 31 below shall have effect with respect to the rent recoverable for any statutory period under a regulated tenancy of the dwelling-house.
(5)In relation to any rental period beginning after a tenancy has become a converted tenancy, this and the two next following sections shall have effect as if references therein to the last contractual period were references to the last rental period beginning before the conversion.