Appeal 3337082

The appeal is allowed and planning permission is granted for a mansard roof extension and front garden alterations which include relocating the stairs and enlarging the lightwell size in accordance with the terms of the application [name]/23/05544, dated 17 August 2023, subject to the following conditions:

The development hereby permitted shall begin not later than three years from the date of this decision.

The development hereby permitted shall be carried out in accordance with the following approved plans: Location plan and drawing numbers 1884/3/C/01 - 001/00, 099/00, 100/00, 101/00, 102/00, 103/00, 104/00, 200/00, 201/00, 202/00, 203/00, 300/00 and 303/00.

The roof slopes of the extension hereby permitted shall be clad in natural slates to match those on the existing roof, the cheeks of the dormer windows hereby permitted shall be clad in lead and the windows hereby permitted shall be white painted timber with double hung sliding sashes. These features shall thereafter be retained as approved.

I understand from the appellant that amended plans were submitted during the application process, including removal of the lightwell and stair alterations from the proposal. As the Council did not consider those plans, the changes have not been publicised for comment. In order to avoid prejudice to other parties, I assess this appeal on the basis of the plans considered by the Council. I note in any case that the Council raises no objection to the front garden alterations.

The main issue is whether the proposal would preserve or enhance the character or appearance of the Kensington Conservation Area.

The conservation area is described by the Council’s Kensington Conservation Area Appraisal (CAA) as a relatively secluded, intimate residential backwater of elegant, largely mid-19th Century terraces. The CAA further says that [address] is characterised by attractive groups of modest mid-Victorian terraced houses which have similar architectural elements and share a similar palette of materials.

No 18, together with all neighbouring buildings, is noted in the CAA as a positive contributor to the conservation area. It is a 4 storey (including the lower ground floor) end of terrace town house on a corner plot, with its front door facing [address]. The proposal would replace its very low pitched roof with a mansard style roof including 2 small dormer windows.

The Council considers that the addition of a mansard roof here would be an uncharacteristic form of development, but mansard roofs and dormer windows are overwhelmingly common within this local area. This includes the adjacent row of houses at 3 to [address], as noted in the CAA. Due to its location and orientation, [site address] reads as more a part of [address] than as part of [address]. The proposed mansard and dormers would fit in well in this context.

The Council refers to the unbroken roofline of the terrace on [address], but the addition of a mansard roof to No 18, sitting at the low end of this terrace, would not look at all out of place, adding a visual stop at the end of the row. The mansard and dormers would not be overly tall or bulky and would be partly screened by a parapet wall, so that their visual presence would be limited in any case. The new roof line would not intrude on any clear skyline views. The overall effect would be of a high quality and discreet addition that would complement existing development.

Local Plan policy CL8 says that the Council will resist roof level alterations on complete terraces or groups of buildings where the existing roof line is unimpaired by extensions. Each case must, however, be taken on its merits and in this case, I find no harm to the character of the terrace from a change to the roof of this end of terrace, corner building.

I conclude that the proposal would preserve and enhance the character and appearance of the conservation area. It accords in this respect with policies CL1, CL2, CL3, CL6, CL8 and CL11 of the Local Plan, which seek to secure high quality design for all development, including roof alterations, that contributes positively to the townscape and protects the special architectural or historic interest of conservation areas. In coming to this conclusion, I give special attention to the desirability of preserving or enhancing the character or appearance of the conservation area as required by Section 72 of the Planning (Listed Buildings and Conservation Areas) Act 1990. The Council also refers to an emerging New Local Plan in the documentation but accords that plan only limited weight and does not cite any of its policies in the refusal notice.

I impose a condition listing the relevant plans to provide certainty. A condition specifying external materials is necessary to protect local character and appearance. The Council also requests a condition requiring submission and approval of a Checklist and Site Construction Management Plan to help protect the amenity of neighbouring occupiers during construction. This would be a small scale development, however, and no special reason has been put forward to justify the need for such a condition. The development would be subject to other legislation controlling potential nuisance from construction works.

I find that the proposal accords with the development plan for the area. For the reasons set out above, and having regard to all other matters raised, I conclude that the appeal should succeed.