Appeal 3292660

The appeal is dismissed.

The main issues in this case are the effects of the rear extension on: • The character and appearance of the host property and the surrounding area along [name], and • The living conditions of the occupiers of Nos 16 and [address] of light and outlook.

No 18 is a mid-terraced property situated on the southern side of [name]. It has a full-width rear roof dormer and a large single-storey rear extension, with another, smaller single-storey rear extension projecting further into the rear garden, against the boundary with No 20. The proposed development would involve the construction of a first-floor rear extension, some 3.5 metres wide and 3 metres deep, above the central portion of the existing ground-floor rear extension.

Policy CS1 of the Council’s Core Strategy (CS) indicates that new development should protect the character of Harrow’s suburbs. Policy DM1 of the Council’s Development Management Policies document (DMP) indicates that all development must achieve a high standard of design and layout. The assessment of this should have regard to the massing, bulk, scale and height of proposed buildings in relation to the location and the surroundings; the appearance of proposed buildings, including detailing and roof form; and the context provided by neighbouring buildings and the local character.

The Harrow Residential Design Guide (SPD) includes guidance for Householder Development. This indicates that extensions should represent an additional volume subordinate to, and reflecting, the character of the original house, or a simple extension of the existing building form. In addition, an extension should have a sense of proportion and balance, both in its own right and in its relationship to the original building and should not dominate the original building, whilst roof design is very important because this will determine the overall shape of the extension.

With regard to rear extensions, the SPD notes that there is potential for harm to the amenities of neighbouring residents. In addition, their impact on neighbouring property and the character and pattern of development needs careful consideration. Rear extensions should be designed to respect the character and scale of the original house and garden and should not cause unreasonable loss of amenity to neighbouring residents, while all roofs should be designed to reflect the character of the dwelling house and those adjoining to provide a satisfactory appearance.

The Council contends that the combined excessive scale, bulk and poor design of the proposed extension together with the existing rear dormer would give rise to a contrived and incongruous form of development, and result in excessive and overly dominant extensions which would fail to respect the proportions and scale of the original dwellinghouse. In addition, the proposed first floor extension, by reason of its rearward projection and siting in relation to No. 20 and No. 16 [name], would result in a loss of outlook and give rise to an overbearing visual impact on the neighbouring dwellinghouses, to the detriment of the residential and visual amenities of their occupiers.

The appellant contends that the proposal would provide a development that would appear subordinate and congruous by virtue of its design, scale and height and proportion. Moreover, the rear of the properties in the area is characterised by properties which are dominated by residential extensions and additions of various scale, sizes and proportions. Finally, he contends that while the proposal would have a level of impact on neighbouring property, the degree of impact would not be significantly harmful such as to refuse the grant of planning permission.

Character and appearance

From my visit, it would appear that a large number of houses in the immediate locality have single-storey rear extensions of varying scale and design. None, however, appear to have a dormer extension of full height and width such as exists at the appeal property. The rear ground-floor extension at No 18 coupled with the rear dormer extension, together represent a large addition to the scale and massing of the house. The further development of the proposed first-floor rear extension would result in a complex set of additions that would dominate the original dwellinghouse and would not appear subordinate to it.

Moreover, the proposed extension would appear somewhat incongruous across the central portion of the rear elevation, with a hipped roof cutting across the rear elevation of the dormer extension. It appears that it would be the only such first-floor rear extension along this part of [name], and it would, therefore, be out of character with the immediate locality.

I note the comments of the Council regarding roofs as outlined in Paragraph 6.71 of the SPD, but the guidance here would appear to relate to houses with rear outriggers, which is not the case with the appeal property. Nevertheless, the proposed extension would not relate well to the existing host property in terms of its appearance and its impact on the scale and massing of the house.

The proposed extension would have a depth of 3 metres and would be set in around 2 metres from the boundary with No 20. The nearest window in the first-floor rear elevation of No 20 appears to be set in around 1 metre from the boundary. I have no details as to whether this is a ‘protected’ or habitable room window, although it has the appearance of a bathroom. In any event, given the distance of the proposed extension from this window, I do not consider that the proposed extension would be harmful to the visual impact from inside the adjacent property. Moreover, given that there is already a single-storey extension at the appeal property on the boundary with No 20, I do not consider that the proposed first-floor extension, in itself, would be likely to break any meaningful 45 degree line from the bottom of a protected window in the ground-floor rear elevation at No 20.

The proposed extension would be set in almost 3 metres from the boundary with No 16. Given that the nearest ‘protected’ or habitable room window in the first-floor rear elevation of No 16 is not on the boundary, and that there is a large ground-floor rear extension at the property, I do not consider that the proposal would have any harmful impact on light received by or outlook from that house.

On this issue, therefore, by virtue of its limited depth and the amount of set-in from the property boundaries, I find that the proposed extension would not be significantly harmful to the light received by, or the outlook from, the rear of Nos 16 and 20.

In conclusion, I find that the proposed extension, by virtue of its cumulative scale and massing in conjunction with the existing large roof dormer and single-storey rear extensions, would be harmful to the character and appearance of the host property and the neighbouring surroundings along [name]. In addition, the somewhat incongruous design, with a hipped roof cutting across the rear elevation of the dormer, would not respect the context of the existing house or its immediate locality. On this basis, it would conflict with Policy CS1 of the CS, Policy DM1 of the DMP, and guidance on [name] given in the SPD.

I find that the proposal would not be significantly harmful to the living conditions of the occupiers of Nos 20 or 16 [name], by way of light or outlook. Nevertheless, this lack of harm does not compensate for the harm that would be caused to the character and appearance of the appeal property itself and the surrounding area. Accordingly, I dismiss this appeal.