Appeal 6003062

The appeal is dismissed insofar as it relates to the rear box dormer.

The appeal is allowed and planning permission is granted insofar as it relates to the single storey front and rear extensions, the hip to gable roof alteration and rooflights to front roof slope at [site address] in accordance with the terms of the application, PL/2472/25, and the plans submitted with it, subject to the following conditions:

The development hereby permitted shall begin not later than 3years from the date of this decision.

The materials to be used in the construction of the external surfaces of the development hereby permitted shall match those used in the existing building.

The development hereby permitted shall be carried out in accordance with the following approved plans, drawings: PE-01 REV01, 02 REV01, AB-01 REV01, 02 REV 01, 03 REV 01, 04–[name] 01, PR-01 REV 01,02 REV 01, 03 REV01, BLOCK PLAN scale 1:500 and LOCATION PLAN scale 1:1250 insofar as the drawings relate to those parts of the proposal that are approved.

I consider the main issue to be the effect on the architectural integrity of the host property.

The appeal property, number [site address] is a two-storey semi-detached dwelling. It is located in a residential street. [name] observed, although extended and altered over time the dwellings nearby have generally, but not exclusively retained their hipped roof form.

The appellants propose a single storey front extension, single storey side and rear extension, alterations to the roof to form a gable end with a window rear box dormer together with rooflights to front roof slope along with associated external works.

Alterations to the roof including the gable end, and rear dormer were the subject of a previous appeal to determine whether at the time of the application they constituted permitted development. That appeal Ref: APP/M5450/X/23/3334807 was dismissed. However, this consideration has no weight in respect of my determination of this appeal which I will consider on its own planning merits.

[name] observed on the occasion of my site visit the proposed single storey front, side and rear extensions together with the new gable end, rear box dormer, roof windows to front roof slope and external alterations have all been undertaken but await external finishes.

The Council consider that the single storey rear extension would be in keeping with the established pattern of development in the area and is therefore acceptable. Further, it regarded the front extension to be acceptable in the light of other front extensions in the area. The proposed porch, part of the proposed front extension was approved by the local planning authority under its Ref: P/1462/22 and was therefore found acceptable. From what I have seen and read I have not formed a contrary view in respect of these matters.

From the evidence before me I also note that the Council raise no objection to the proposed gable end roof alteration or the proposed rooflights to the front slope. Based on what I have seen and read I have again not formed a contrary view.

My attention has been drawn to the Harrow Supplementary Planning Document Residential [name] (2010) (SPD). The advises that amongst other things: roof alterations and dormer windows should complement the original street character and not dominate buildings or impair their proportions or character. Dormers should be subordinate features in the roof, should not overlap or wrap around the roof hips, and should never rise above the ridge. In order to reduce its visual impact, such a rear dormer should be set in at least 1000mm from the edge (or verge) of the roof and 500mm from a shared (party) wall, and 500mm from an adjacent valley on a return roof and set at least 1000mm above the roof eaves.

Due to the overall scale, size and design of the rear dormer as built it would, in addition to failing to accord with the guidance set out in the Council’s SPD, appear as dominant, bulky and visually incongruous feature here.

The exposed side of the box dormer and the new gable end would both be open to public view from the street, through the gap between No.1 and No.3. Cumulatively the box dormer and gable end when viewed together would appear bulky and visually unattractive. Accordingly, the box dormer would result in significant visual harm to not only the architectural integrity of the existing dwelling but as an unattractive alien feature in the street scene.

I conclude in respect of the main issue that the proposed box dormer would fail to accord with the objectives of the National Planning Policy Framework (2024), Policy D3.D (1) and (11) of the London Plan (2021), Policy DM1 of the Harrow Development Management Policies Local Plan (2013) and the adopted Harrow Supplementary Planning Document Residential [name] (2010) as well as Policy GR1 of the Draft Harrow Local Plan 2021-2041 as they relate the quality of design.

My attention has been drawn to similar box dormers in the surrounding areas. Whatever the background to those cases they are not an appropriate justification for permitting another here.

The need for accommodation for larger families is noted. However, I do not believe that in this case this consideration outweighs the harm to the architectural integrity of the host property or the character of the wider area that the proposed box dormer would cause.

The single storey rear extension and the front extension, including the porch, hip to gable alteration and rooflights to front roof slope are not disputed by the local planning authority, and I conclude that they would not cause harm to the either the architectural integrity of the host property or the character and appearance of the area and should therefore be permitted.

To ensure a high quality development, I shall include a condition about the materials to be used in the construction of the external surfaces of the building.

In the interests of certainty, I shall impose a condition requiring the development to be undertaken in accordance with the approved plans.

For the reasons given above and having regard to all other matters raised, I conclude that the appeal should be allowed only in part but otherwise dismissed.