30.—(1) An allowance shall be granted in accordance with paragraph (2) to any person entitled to serve a notice under Article 29(1) in respect of a hereditament which either is a dwelling-house, or, though not a dwelling-house, is used partly for the purposes of a private dwelling whether or not he has in fact served such a notice, who pays the net amount due on account of a rate in respect of that hereditament[F1 in a single sum before such date] as the Department may notify to him.
(2) The allowance shall be by way of a discount of[F1 4 %] on—
(a)in the case of a dwelling-house, the amount payable on account of the rate; or
(b)in the case of a hereditament which, though not a dwelling-house, is used partly for the purposes of a private dwelling, so much of the amount payable on account of the rate as is computed by reference to the domestic element of the rateable value of the hereditament.
[F1(2A) The Department may by order direct that for the percentage mentioned in paragraph (2) there shall be substituted such other percentage as may be specified in the order.
(2B) An order under paragraph (2A) shall be subject to affirmative resolution and shall have effect from the beginning of the year after that in which it is made.]
(3) If an allowance under this Article is made in respect of a hereditament in respect of which a notice under Article 29(1) is in force, that notice shall thereupon cease to be in force and, notwithstanding anything in Article 29(1), rates in respect of that hereditament shall cease to be payable in accordance with that Article, without prejudice, however, to the right to serve a fresh notice under Article 29(1) in accordance with paragraph 1 of Schedule 9.
(4) In this Article “the domestic element of the rateable value of the hereditament” means so much of the rateable value as consists of or is derived from the amount of the net annual value apportioned in the valuation list to the use of the hereditament for the purposes of a private dwelling.