(1)Where, for any rental period, there is with respect to—
(a)the provision of services for the tenant by the landlord or a superior landlord, or
(b)the use of furniture by the tenant under the terms of the tenancy,
or any circumstances relating thereto any difference, in comparison with the basic rental period, such as to affect the amount of the rent which it is reasonable to charge, the rent limit shall be increased or decreased by an appropriate amount.
(2)Where, for any rental period, the rent limit is increased by an appropriate amount under subsection (1) above, the rent for that period shall, notwithstanding anything in section 28 of this Act and without the service of any notice, be increased by the like amount.
(3)Any question whether, or by what amount, the rent limit is increased or decreased by virtue of subsection (1) above shall be determined by agreement in writing between the landlord and the tenant or by the county court.
(4)Any determination under subsection (3) above—
(a)may be made so as to relate to past rental periods; and
(b)shall have effect with respect to rental periods subsequent to the periods to which it relates until revoked or varied by any such agreement as is referred to in subsection (3) or by the county court.