Appeal 6005630

The appeal is dismissed.

[address] is divided into two flats, and the application relates to the first floor flat. At my site visit there was limited access to parts of the rear garden, but I was able to see sufficient to come to a view on the proposed development. Additionally, the appellant has provided an aerial view showing buildings in the surrounding area.

The main issue is the effect of the proposed development on the character and appearance of the host property and the surrounding area.

The appeal site is part of a two-storey house forming a pair with [address] (no 14), with a pitched roof to the main building and a two- and single-storey rear outrigger. The outrigger has a flat roof which sits below the eaves line of the main building.

[address] is a residential street characterised by closely spaced, two-storey terraced and semi-detached houses. While the appeal building is not in a conservation area or otherwise designated, it forms part of the established character of the street. Some houses have outriggers to the rear, which are of varying heights and different forms, with outdoor areas in the return. The outriggers immediately neighbouring the appeal property are generally two-storey with flat or mono-pitch roofs, handed with their neighbours.

The proposed rear dormer would extend across almost the full width of the host dwelling. It would be set in slightly from the rear wall of the main house, and set in marginally from the side elevation. Its flat roof would align with the ridge height of the main building and its walls would be slate hung. The extension would continue along part of the rear outrigger, although the height of that element would be below that of the proposed rear dormer.

The Council’s Residential Design Guide Supplementary Planning Document (SPD), adopted in 2016, is a material consideration. It advises that dormer roof extensions should normally be subordinate features on the roof and should not occupy more than half the width or half the depth of the roof slope. It also sets out that in general, extensions should be subordinate to the original house, respect the original building, and should not be overly dominant.

The proposed roof extension would not comply with advice in the SPD. By virtue of its width, height, massing and materials it would be a bulky and overly dominant addition. It would fail to relate successfully or sensitively to the host building. Its inappropriate and poor design would be exacerbated by the similarly bulky and overbearing single-storey extension on the rear outrigger. This element would appear as a fragmentary addition to the host building, and its piecemeal nature would be compounded by the asymmetry it would create with the rear of No 14. Although it would not impact on the street scene, the proposed extension would be highly visible to the rear, with considerable intervisibility between properties, and thereby cause harm to the wider area.

For these reasons, I conclude that the proposed development would harm the character and appearance of the host property and the surrounding area. It would conflict with Policies CDH01 and CDH05 of the Barnet Local Plan, 2025. Taken together, these policies seek to deliver high quality design and extensions which complement the character of the existing building, particularly in terms of style, form and materials, as well as expecting development to respond sensitively to the distinctive local character and design, building form, scale, massing, and roof form of the existing context. They also seek to ensure that extensions are subordinate to the existing building in terms of size, scale and/or height.

The proposed development also conflicts with Policies D1 and D3 of the London Plan, 2021, which amongst other things seek to deliver high quality development which responds positively to the character of a local area.

Whilst planning permission was granted for a roof extension in 2022 at the appeal site, this permission has now expired. I have limited details of that proposal, the planning policy context, or the decision made by the Council at that time, though I note that a further application for a roof extension was also refused by the Council, and that the development plan has since changed. Accordingly, while there was clearly considered to be some potential for roof development at that time, the planning history of the site has not had a significant bearing in my consideration of this appeal, which I have assessed on its own merits against the current development plan policies.

In the description of development, the appellant has made reference to similar development in the area, but has subsequently provided little detail of any cases. At my site visit I did not observe any comparable L-shaped rear extensions and none are evident in the view submitted by the appellant. I acknowledge that the absence of any directly comparable, existing development should not preclude otherwise acceptable development of a different form, but that does not justify the harm I have found in this case.

At my site visit I observed some roof conversions and full width rear dormers, although I do not know the circumstances surrounding their construction. Similarly the evidence submitted indicates incremental changes to some buildings in the area. However, the area retains its residential character and the existence of full width dormers, and other extensions, elsewhere has not altered my overall

My attention has also been drawn to a number of other streets in Barnet where the appellant contends similar extensions exist. I have not been provided with full details of these examples and therefore, I cannot be certain as to the reasoning behind these decisions. In any case, each planning proposal is assessed on its own merits. I have come to a decision based on the circumstances of this case.

The appellant states that the site has good access to local services and shops and that the proposal would provide a more functional three-bed home, thereby making more efficient use of the existing building. These are benefits which weigh in favour, of the proposal, but which would be limited by the scope and scale of the extension. Such minor benefits therefore do not outweigh the permanent harm to the character and appearance of the host property and the surrounding area that I have found.

A number of comments have been made by interested parties, raising several other issues; including possible impacts on outlook, privacy, on-street car-parking and loss of light. These issues were considered by the Council at application stage, and I have not been presented with any additional evidence to support my coming to a different view. However, I have concluded that the proposed extension would be a dominant and overbearing structure, and at my site visit I observed that it would be particularly obtrusive in views from neighbouring properties. These effects have formed part of my conclusions regarding the effect of the proposal on the character and appearance of the area.

The proposal conflicts with the development plan and material considerations do not indicate that the appeal should be decided other than in accordance with it. I therefore conclude that the appeal should be dismissed.