5(1)Development shall be carried out in accordance with plans and specifications for the time being approved by the local planning authority at the request of the nominated undertaker.
(2)The local planning authority may, on approving a plan or specification for the purposes of this paragraph, specify any respect in which it requires additional details of the development to be submitted for approval.
(3)Where the local planning authority exercises the power conferred by sub-paragraph (2) above, the plans and specifications in accordance with which the development is required under sub-paragraph (1) above to be carried out shall, as regards the specified respect, include a plan or specification showing the additional details.
(4)The only ground on which the local planning authority may refuse to approve plans or specifications for the purposes of this paragraph is—
(a)that the development to which they relate ought to, and could reasonably, be carried out elsewhere on land within the relevant limits, or
(b)that the design or external appearance of any building to which they relate ought to be modified to preserve the local environment or local amenity and is reasonably capable of being so modified.
(5)The ground mentioned in sub-paragraph (4)(a) above shall not apply in relation to development consisting of the provision of, or the carrying out of works to, a dam.