(1) The tax under Cases I and II of Schedule D shall be charged without any deduction other than is allowed by the Tax Acts.
(2) Subject to the Tax Acts, in computing the amount of the profits or gains to be charged to tax under Case I or II of Schedule D, no sum shall be deducted in respect of -
(a) any disbursement or expenses, not being money wholly and exclusively laid out or expended for the purposes of the trade or profession;
(b) any disbursements or expenses of maintenance of the parties, their families or establishments, or any sums expended for any other domestic or private purposes distinct from the purposes of such trade or profession;
(c) the rent of any dwelling house or domestic offices or any part of any dwelling house or domestic offices, except such part thereof as is used for the purposes of the trade or profession, and, where any such part is so used, the sum so deducted shall be such as may be determined by the inspector and shall not, unless in any particular case
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