4 Assessment of compensation: general provisions.E+W
(1)The compensations payable on any claim shall be assessed by reference to prices current on [the first claim day].
(2)In assessing depreciation due to the physical factors caused by the use of any public works, account shall be taken of the use of those works as it exists on [the first claim day] and of any intensification that may then be reasonably expected of the use of those works in the state in which they are on that date.
(3)In assessing the extent of the depreciation there shall be taken into account the benefit of any relevant works—
(a)which have been carried out, or in respect of which a grant has been paid, under section 20 below, section 15 of the Airports Authority Act 1965 [, section 29A of the Civil Aviation Act 1971][, section 79 of the Civil Aviation Act 1982]or any corresponding local enactment [or under any provision of a scheme operated by a person managing an aerodrome which provides for the payment of sound-proofing grants in respect of buildings near the aerodrome];
(b)which have been carried out under section 23 or 27 below;
and it shall be assumed that any relevant works which could be or could have been carried out, or in respect of which a grant could be or could have been paid, under any of the provisions mentioned in paragraph (a) above have been carried out but, in a case where the authority having functions under that provision have a discretion whether or not to carry out the works or pay the grant, only if they have undertaken to do so.
[In paragraph (a) above “sound-proofing grants”, in relation to any buildings, means grants towards the cost of insulating those buildings or parts of those buildings against noise.]
(4)The value of the interest in respect of which the claim is made shall be assessed—
(a)subject to subsection (5) below, by reference to the nature of the interest and the condition of the land as it subsisted on the date of service of notice of the claim;
(b)subject to section 5 below, in accordance with rules (2) to (4) of the rules set out in section 5 of the Land Compensation Act 1961;
(c)if the interest is subject to a mortgage or to a contract of sale or to a contract made after the relevant date for the grant of a tenancy, as if it were not subject to the mortgage or contract.
(5)In assessing the value of the interest in respect of which the claim is made there shall be left out of account any part of that value which is attributable to—
(a)any building, or improvement or extension of a building, on the land if the building or, as the case may be, the building as improved or extended, was first occupied after the relevant date; and
(b)any change in the use of the land made after that date.
(6). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .