It is considered that the installation of a dormer window of the design and position indicated would be harmful to the existing simple character and appearance of the property and would undermine the visual unity of the terrace as a whole to the detriment of the visual amenities of the area. Furthermore, if permitted, the development would set a precedent for the installation of dormer windows on other properties in the terrace, the cumulative impact of which would adversely affect its existing appearance and the visual amenities of the area. The proposal is therefore contrary to policy H8 of the Local Plan which seeks to ensure that alterations to dwellings do not detract from the character of the host building and policy GP3 which requires that new development respects or enhances the character, special qualities and distinctiveness of the locality.