Chapter 3 of Part 10 of the Principal Act is hereby amended -

(a) in section 339(2), by the insertion after paragraph (c) of the following paragraph:

"(d) Where, in relation to the construction of, conversion into, refurbishment of, or, as the case may be, construction or refurbishment of a building or structure which complies with the requirements of subparagraphs (i), (ii) and (iii) of paragraph (c), being a qualifying premises within the meaning of section 346, 347, 348 or 349, where -

(i) the expenditure to be incurred on the house has not been fully incurred by the 31st day of December, 1998, and

(ii) the relevant local authority gives a certificate in writing on or before the 28th day of February, 1999, to the person constructing, converting or refurbishing, as the case may be, the house stating that it is satisfied that not less than 50 per cent of the total cost of the house and the site thereof had been incurred on or before the 31st day of December, 1998,

then, the reference in paragraph (a) of the definition of 'qualifying period' in subsection (1) to the period ending on the 31st day of July, 1997, shall be construed as a reference to the period ending on the 30th day of April, 1999.",