If, before the expiration of the period within which a building in respect of which a demolition order is made under this Part of this Act is thereby required to be vacated, any owner or owners, whose estate or interest, or whose combined estates or interests, in the building and the site thereof is or are such that the acquisition thereof by the local authority would enable the local authority to carry out the demolition provided for by the order, make to the local authority an offer for the sale of that interest, or of those interests, to the local authority at a price to be assessed, as if it were compensation for a compulsory purchase subject to observance of the rules specified in Part III of the Third Schedule to this Act, the authority shall accept the offer and shall, as soon as possible after obtaining possession, carry out the demolition.

If no such offer as is mentioned in the foregoing subsection is made before the expiration of the said period, the owner or owners of the building shall carry out the demolition provided for by the order before the expiration of six weeks from the last day of that period, or, if the building, or such part thereof as is required to be vacated, is not vacated until after that day, before the expiration of six weeks from the day on which it is vacated or, in either case, before the expiration of such longer period as in the circumstances the local authority deem reasonable, and if the demolition is not so carried out the local authority shall enter and carry out the demolition and sell the materials rendered available thereby.

The provisions of subsections (2) to (5) of section twenty-three of this Act shall apply in relation to any expenses incurred by a local authority under the last foregoing subsection and to any surplus remaining in the hands of the authority, as they apply in relation to any expenses or surplus in a case where a house is demolished in pursuance of a demolition order made under Part II of this Act, with the substitution of references to the building demolished under this section for references to the premises demolished under the said section twenty-three.

Where the demolition of a building is carried out under subsection (2) of this section, either by the owner or owners thereof or by the local authority, compensation shall be paid by the authority to the owner or owners in respect of loss arising from the demolition, and that compensation shall, notwithstanding that no land is acquired compulsorily by the local authority, be assessed in accordance with the Acquisition of Land (Assessment of Compensation) Act, 1919, subject to observance of the rules set out in Part III of the Third Schedule to this Act except that paragraphs (2) to (6) of section two of the said Act of 1919 shall not apply and that paragraph (1) of the said section two shall have effect with the substitution of a reference to demolition for the reference to acquisition.

Subsection (1) of section thirty-three of this Act shall have effect for the purpose of enabling the owner of a house to obtain notice of any proceedings for the making of a demolition order under this Part of this Act with respect to the house.

Nothing in the provisions of this Part of this Act relating to demolition orders shall prejudice or interfere with the rights or remedies of any owner for the breach, non-observance or nonperformance of any covenant or contract entered into by a tenant or lessee in reference to any house in respect of which such an order is made; and if any owner is obliged to take possession of a house in order to comply with any such order, the taking possession shall not affect his right to avail himself of any such breach, non-observance or non-performance which has occurred before he so took possession.