157.14. Where, by reason of section 135.4, no amount would, but for this section, be deductible by a taxpayer in respect of an outlay or expense in respect of a building, or part thereof, and the outlay or expense would, but for section 135.4 and this section, be deductible in computing the taxpayer’s income for a taxation year, there may be deducted in respect of such an outlay or expense in computing the taxpayer’s income for the year an amount equal to the lesser of(a) the aggregate of all amounts each of which is such an outlay or expense, and
(b) the taxpayer’s income for the year from renting the building or the part thereof, computed without reference to section 157.13 and this section.