(1)An improvement grant in respect of the expenses incurred for the purpose of the execution of improvement works shall, subject to the following provisions of this section, be paid—
(a)within one month of the date on which, in the opinion of the local authority, the house first becomes fit for occupation after the completion of the works; or
(b)partly in instalments paid from time to time as the works progress and with a final settlement of the balance within one month of the completion of the works but the aggregate of the instalments paid shall not at any time before the completion of the improvement works exceed 50 per cent., or such other percentage fixed by virtue of section 242(1), or, as the case may be, section 244(6) of the aggregate approved expense of the works executed up to that time.
(2)The payment of an improvement grant or of an instalment or the balance thereof shall be conditional on the improvement works, or, as the case may be, the part of the works which the local authority consider will entitle the applicant to payment of the instalment or of the balance of the grant, being executed to the satisfaction of the local authority.
(3)Where an instalment of an improvement grant is paid before the completion of the works, and the works are not completed within 12 months of the date of payment of the instalment, then that instalment and any further instalment paid by the local authority on account of the grant shall, on being demanded by the authority, forthwith become payable to them by the person to whom the instalments were paid, and the instalments shall carry interest at such reasonable rate as the local authority may determine from the date on which they were paid by the authority until repaid under this subsection.