Other kinds of improvements

When the improvement is not an improvement to which section 9 or 10 applies, the compensation to be awarded shall be the cost of the labour, including supervision thereof, and of the materials, together with other expenditure, if any, which would at the time of the valuation be required to make the improvement, less a reasonable deduction on account of the deterioration, if any, which may have taken place since the improvement was made by reason of usage or other cause.