(1) As respects any tax year, in the case of an individual who carries on a trade, including a trade carried on by 2 or more individuals in partnership, otherwise than as an active trader or an active partner, where a capital allowance, in relation to a building or structure, is made to the individual either in taxing that trade or by means of discharge or repayment of tax to which the individual is entitled by reason of the individual carrying on the trade concerned, then -
(a) the capital allowance shall be made to the individual only in computing the income or profits from the trade concerned, and
(b) the capital allowance shall not be made in computing any other income or profits or in taxing any other trade or in charging any other income to tax.
(2) As respects any chargeable period, in computing the amount of profits or gains for the purposes of Case V of Schedule D -
(a) any capital allowance in respect of a building or structure to be made to a person -
(i) shall not exce