133The amount to be secured.
(1)The amount which a secure tenant exercising the right to a mortgage is entitled to leave outstanding, or have advanced to him, on the security of the dwelling-house is, subject to the limit imposed by this section, the aggregate of—
(a)the purchase price,
(b)so much of the costs incurred by the landlord or the Housing Corporation as is chargeable to the tenant under section 178(2) (costs), and
(c)any costs incurred by the tenant and defrayed on his behalf by the landlord or the Housing Corporation.
(2)The limit is that the amount which the tenant is entitiled to leave outstanding or have advanced to him on the security of the dwelling-house may not exceed—
(a)where the right to a mortgage belongs to one person, the amount to be taken into account, in accordance with regulations under this section, as his available annual income multiplied by such factor as, under the regulations, is appropriate to it;
(b)where the right to a mortgage belongs to more than one person, the aggregate of the amounts to be taken into account in accordance with the regulations as the available annual income of each of them, after multiplying each of those amounts by the factor appropriate to it under the regulations.
(3)The Secretary of State may by regulations make provision for calculating the amount which is to be taken into account under this section as a person’s available annual income and for specifying a factor appropriate to it; and the regulations—
(a)may provide for arriving at a person’s available annual income by deducting from the sums taken into account as his annual income sums related to his needs and commitments, and may exclude sums from those to be taken into account as a person’s annual income, and
(b)may specify different amounts and different factors for different circumstances.
(4)Where the amount which a secure tenant is entitled to leave outstanding on the security of the dwelling-house is reduced by the limit imposed by this section, the landlord may, if it thinks fit and the tenant agrees, treat him as entitled to leave outstanding on that security such amount exceeding the limit, but not exceeding the aggregate mentioned in subsection (1), as the landlord may determine.
(5)References in this Part to a secure tenant being entitled, or treated as entitled, to a “full mortgage” are to his being entitled, or treated as entitled, to leave outstanding or have advanced to him on the security of the dwelling-house an amount equal to the aggregate mentioned in subsection (1).
(6)Regulations under this section—
(a)may make different provision with respect to different cases or descriptions of case, including different provision for different areas, and
(b)shall be made by statutory instrument which shall be subject to annulment in pursuance of a resolution of either House of Parliament.