(1)This section applies if in a tax year a person —
(a)is the owner or tenant of any premises, and
(b)incurs expenditure in making a sea wall or other embankment necessary for the preservation or protection of the premises against the encroachment or overflowing of the sea or any tidal river.
(2)In calculating the profits of any property business (within the charge to tax under Chapter 3) carried on by the person in relation to the premises, a deduction is allowed for the expenditure in each tax year comprised in the deduction period.
(3)The deduction period comprises—
(a)the tax year in which the expenditure is incurred, and
(b)the next 20 tax years.
(4)The amount of the deduction is 1/21 of the expenditure.
(5)The deduction is apportioned between the accounting period or periods comprised in the tax year, but—
(a)no apportionment is made to an accounting period which ends before the expenditure is incurred, and
(b)if the person is entitled to the deduction because of a transfer dealt with by section 255, no apportionment is made to an accounting period which ends before the transfer takes place.
(6)In the case of the transfer of an interest in the premises dealt with by section 255, this section applies as if the reference to the person in subsection (2) above included the transferor and the transferee.
(7)No deduction is allowed for any expenditure in respect of which a capital allowance has been made.