The relevant conditions set out in A.2 (2) state that development consisting of (a) the erection, extension or alteration of a building; is permitted by Class A subject to the following condition— (i) the developer must, before beginning the development, apply to the local planning authority for a determination as to whether the prior approval of the authority will be required as to the siting, design and external appearance of the building. The proposed extension would be corrugate steel sheeting in grey and the roofing proposed would also be of corrugate steel sheeting in grey. The height to the ridge of the roof would be approximately 7.04m. The proposed materials and colour palette would be appropriate to the rural setting of the site. Given the scale, nature and location of the development, officers consider the proposal acceptable in regard to its design, visual amenity and respect of the character of the immediate locality. Therefore, the proposal is considered appropriate for the purposes of agricultural use and acceptable in its siting, design and external appearance. Therefore, prior approval is not required from the Local Planning Authority.