(1)The amount of a standard grant shall, subject to subsection (2) of this section, be one-half of the costishown to have been incurred in executing the works in respect of which it is made.
(2)The amount of a standard grant shall not exceed one hundred and fifty-five pounds if at the time the works were begun the dwelling was provided with none of the standard amenities and, in any other case, shall not exceed that amount reduced by the following amounts respectively for each of those amenities with which the dwelling was then provided, that is to say—
(a)by twenty-five pounds for the amenity mentioned in paragraph (a),
(b)by five pounds for that mentioned in paragraph (b),
(c)by seventy-five pounds for that mentioned in paragraph (c),
(d)by forty pounds for that mentioned in paragraph (d),
(e)by ten pounds for that mentioned in paragraph (e),
of subsection (1) of section four of this Act.
(3)The reduction required by subsection (2) of this section in respect of any of the standard amenities shall not be made if part of the cost incurred in executing the works was attributable to interference with or replacement of that amenity and the local authority are satisfied that it would not have been reasonably practicable to avoid the interference or replacement.
(4)The Minister may by order vary the amounts specified in subsection (2) of this section, and an order made by the Minister under section four of this Act varying the amenities which are the standard amenities for the purposes of this Part of this Act may specify the reductions to be made under subsection (2) of this section in respect of those amenities respectively.