The proposal involves the replacement of the existing rear extension with one of considerably greater volume and width. It is considered that the bulk, width, projection, and the design detail of the proposed extension would produce a visually obtrusive structure without precedent in this terrace, and would result in an unacceptable degree of harm to the integrity of this building, the special architectural character and historic interest of this group of Listed buildings, and to the character and appearance of this part of the Conservation Area. As such, the proposal is contrary to Policies of the Unitary Development Plan, in particular Policies CD25, CD41, CD44, CD48, CD52, CD53 and CD58.