F.3—(1) Subject to sub-paragraphs (2) and (3), development is permitted by Class F subject to the prior approval of the mineral planning authority of detailed proposals for the siting, design and external appearance of any building, plant or machinery proposed to be erected, installed, extended or altered.E+W
(2) The prior approval referred to in sub-paragraph (1) is not required for any building, plant or machinery which does not exceed the limits set out in paragraph F.1(b), (c) or (d).
(3) The prior approval referred to in sub-paragraph (1) may not be refused or granted subject to conditions unless the authority are satisfied that it is expedient to do so because—
(a)the proposed development would injure the amenity of the neighbourhood and modifications could reasonably be made or conditions reasonably imposed in order to avoid or reduce that injury; or
(b)the proposed development ought to be, and could reasonably be, sited elsewhere.