(1) In this section -
"qualifying lease", in relation to a house, means, subject to section 70(1), a lease of the house the duration of which is not less than 12 months and the consideration for the grant of which consists -
(a) solely of periodic payments all of which are, or fall to be treated as, amounts by way of rent for the purposes of Chapter VI of Part IV of the Income Tax Act, 1967, or
(b) of payments of the kind mentioned in paragraph (a) together with a payment by way of a premium which does not exceed 10 per cent. of the relevant cost of the house;
"qualifying premises" means, subject to subsections (2), (3)(a) and (4) of section 70, a house -
(a) the site of which is on a designated island,
(b) which is used solely as a dwelling,
(c) the total floor area of which -
(i) is not less than 30 square metres and not more than 125 square metres in the case where the house is a separate self-contained flat or maisonette in a building of two or more storeys, or
(ii) is not les