11:--

(1) In a lease to which this section applies (as to which, see sections 13 and 14) there is implied a covenant by the lessor . . .

(a) to keep in repair the structure and exterior of the dwelling-house (including drains, gutters and external pipes).

(b) to keep in repair and proper working order the installations in the dwelling-house for the supply of water, gas and electricity and for sanitation (including basins, sinks, baths and sanitary conveniences, but not other fixtures, fittings and appliances for making use of the supply of water, gas or electricity), and

(c) to keep in repair and proper working order the installations in the dwelling-house for space heating and heating water.

(1A) If a lease to which this section applies is a lease of a dwelling-house which forms part only of a building, then, subject to subsection (1B), the covenant implied by subsection (1) shall have effect as if –

(a) the reference in paragraph (a) of that subsection to the dwelling-house included a reference to any part of the building in which the lessor has an estate or interest; and

(b) any reference in paragraphs (b) and (c) of that subsection to an installation in the dwelling-house included a reference to an installation which, directly or indirectly, serves the dwelling-house and which either . . .

(i) forms part of any part of a building in which the lessor has an estate or interest; or

(ii) is owned by the lessor or under his control.

(3) In determining the standard of repair required by the lessor's repairing covenant, regard shall be had to the age, character and prospective life of the dwelling-house and the locality in which it is situated.

(3A) In any case where .

(a) the lessor's repairing covenant has effect as mentioned in subsection (1A), and

(b) in order to comply with the covenant the lessor needs to carry out works or repairs otherwise than in, or to an installation in, the dwelling-house, and

(c) the lessor does not have a sufficient right in the part of the building or the installation concerned to enable him to carry out the required works or repairs.

then, in any proceedings relating to a failure to comply with the lessor's repairing covenant, so far as it requires the lessor to carry out the works or repairs in question, it shall be a defence for the lessor to prove that he used all reasonable endeavours to obtain, but was unable to obtain, such rights as would be adequate to enable him to carry out the works or repairs.