Appeal 3318164

The appeal is dismissed.

The appellant has requested that the appeal be determined with consideration given to a computer-generated image of the completed dwelling. That image is not before me, nor does it appear that the Council has had the opportunity to comment on it. In the interests of fairness, I have assessed the proposal based on the plans and details that were originally submitted to the Council because it was on that basis that planning permission was withheld.

The main issues are the effect of the proposed development firstly, on the character and appearance of the host building and the local area; and secondly, on the living conditions of the occupiers of 54 and [address] with regard to outlook, visual impact and sense of enclosure.

The appeal property is a mainly 2-storey house that lies within a predominantly residential area, wherein dwellings vary in scale, design and general appearance. Like several properties along [address], No 56 has been externally altered and extended. In particular, there is a ground floor rear projection with a flat roof that extends across the full width of the main house.

The proposal is primarily to enlarge No 56 with a part single, part 2-storey rear addition using external materials to match those of the existing dwelling. The new ground floor element would project outwards from the existing back wall of the host building by about 3-metres. The new first floor component would attach to the main 2-storey house with rear and side walls that would be set well back from their counterparts below. A large back garden would remain with the new built form in place.

Combined, the existing and new ground floor rear extensions would appear as a single structure that would span the entire width of the main building with a depth of about 6-metres from the back wall of the main house. This arrangement would exceed the maximum length for such extensions that is advised in the Council’s Supplementary Planning Document, Residential Design Guidance (RDG). While the SPD does it form part of the development plan, nor does it cover every eventuality, it is nevertheless a relevant consideration.

By connecting with the existing rear extension, and given its flat roof form, the proposal would appear as an overly large ‘box like’ addition that would relate poorly to the scale and proportions of the host building. The cumulative effect would be to visually dominate the rear elevation of the main house. That a new first floor component would also be introduced to one side of the new rear façade would reinforce this impression notwithstanding its position set down from the apex of the main roof. The visual impact of the new built form would greater than might be implied simply from a numerical comparison between certain dimensions of the new extension and those of the existing dwelling.

The proposal would not be visible in the local street scene given its position at the back of the main house. Nevertheless, when seen from the back garden of No 56, the new development would appear as an uncharacteristically large and obtrusive development that would materially detract from the character and appearance of the local area.

The Council’s RDG advises that residential extensions should respect and normally be subordinate to the original house. It also notes that such extensions should not be overly dominant. Even applying some flexibility in this case to reflect the extensions and alterations already made to the appeal dwelling, the proposal could not reasonably be described in these ways.

My attention has been drawn to several examples of large rear extensions and flat roof buildings along [address] and in the local area, with some background details and photographs provided. From the limited information provided, none appear to be directly comparable with the appeal scheme in terms of scale and in their relationship with the host building. [name] am unable to draw any meaningful direct parallels with the proposal before me, I attach no more than limited weight to these examples in support of the appeal.

On the first main issue, I conclude that the proposed development would cause significant harm to the character and appearance of the host building and the local area. Accordingly, it conflicts with Policy D3 of the London Plan, Policies CS1 and CS5 of Barnet's Local Plan ([name]), Policy DM01 of Barnet’s Local Plan (Development Management Policies) and the Council’s RDG. These policies and guidance aim to ensure that development represents high quality design and preserves or enhances local character. It is also at odds with the policies of the National Planning Policy Framework, which state that new development should be sympathetic to local character and add to the overall qualities of the area.

The proposed ground floor extension would project beyond the rear elevations of 54 and [address] that are situated on either side of the site. It is the occupiers of these adjacent properties that are most likely to be affected by the proposal.

Views towards the appeal scheme from the back gardens of Nos 54 and 58 would be at an oblique angle and heavily screened by existing vegetation and boundary treatment. From these directions, the new built form may be glimpsed in the context of the taller and more substantial host building. Views from the rear windows of both neighbouring properties would continue to be across their long and largely open back gardens. In that context, the presence of the proposal, while evident, would not be so imposing as to overly dominate, feel oppressive, overbear or unduly heighten a sense of enclosure for the occupiers of Nos 54 and 58.

As the living conditions of the occupiers of these neighbouring properties would not be significantly reduced, I find no conflict with the policies and guidance cited by the Council insofar as they aim to safeguard residential amenity. My favourable finding on this matter does not outweigh the harm that I have identified in relation to the first main issue.

The proposal was revised following the original application submission notably to alter the design and scale of the new extension. There would be no significant loss of natural light to the adjacent properties if the appeal scheme were to proceed. Others raise no objection, including the local Advisory Committee and the occupiers of Nos 54 and 58. However, these matters do not outweigh the significant harm that I have identified.

The Council additionally considers that the proposal, if allowed, would set an undesirable precedent. However, I disagree. Each development should be assessed on its own merits, as I have done.

The proposed development would conflict with the development plan, when read as a whole. There are no material considerations, including the Framework, which indicate that the decision should be taken otherwise than in accordance with the development plan. For the reasons set out above, I therefore conclude that the appeal should be dismissed.