(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 carried on by the person in relation to the premises, a deduction is allowed for the expenditure in each tax year 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)No deduction is allowed for any expenditure in respect of which a capital allowance has been made.
(6)Section 316 deals with the case of an interest in the premises being transferred (and this section applies in that case as if the reference to the person in subsection (2) above included the transferor and the transferee).