The local authority considers that, by reason of its height, design, materials of construction and colour, the fence is incompatible with the architectural design and character of the listed building to which it is attached. The scale of the fence is incongruous in relation to the setting and appearance of the building and, therefore, contrary to the aims of national guidance set out in Planning Policy Guidance 15, which seeks to protect the national heritage in terms of the historic character and setting of listed buildings.