(1) The Finance Act, 1991, is hereby amended by the substitution of the following section for section 117:

"117.

(1) In so far as an inheritance consists of a house or the appropriate part of a house -

(a) at the date of the inheritance, and

(b) at the valuation date,

and is taken by a successor who, at the date of the inheritance, is a lineal ancestor, a lineal descendant (other than a child, or a minor child of a deceased child), a brother or a sister, or a child of a brother or of a sister, of the disponer, and

(i) has resided continuously with the disponer in the house or, where that house has directly or indirectly replaced other property, in that house and in that other property, for periods which together comprised -

(I) in the case where the successor is a brother or a sister of the disponer and has, at the date of the inheritance, attained the age of 55 years, the 5 years immediately preceding the date of the inheritance, and

(II) in any other case, the 10 years immediately preceding the date of the inheritance, and

(ii) is not beneficially entitled in possession to any other house or the appropriate part of any other house,

the estimated market value of the house or the appropriate part of the house shall, notwithstanding anything to the contrary in section 15 of the Principal Act, be reduced by 80 per cent or £150,000, whichever is the lesser: