Appeal 6000587

The appeal is dismissed.

The main issue is the effect of the proposal on the character and appearance of the host property and local area.

The appeal site includes a two-storey, semi-detached dwelling with a cat slide roof to the side. [address] includes other dwellings which were evidently originally built with a similar roof design although I note some have since been altered. Despite these alterations, I observed that the cat slide designs are preeminent and add a pleasant, distinctive feature which makes a meaningful and positive contribution to the character and appearance of the area.

The appeal proposal seeks to erect a first floor side and roof extensions comprising a wraparound dormer along with rooflights to the front. I note that the Council does not take issue with the rooflights.

My attention is drawn to the Council’s ‘Residential Design Guidance’ Supplementary Planning Document (the SPD) (October 2016) which advises with regards to side extensions that setting back the front wall of side extensions from the front building line can help to reduce the visual impact on the street scene. This set back should normally be 1 metre.

The SPD goes on to advise that pitched roofs, following the same pitch as the existing roof, will normally be needed for two storey extensions and be set down at least 0.5 metre from the ridge of the main roof, while 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.

The first floor side extension would not have a setback from the front elevation of the main dwelling. Moreover, the dormer roof extension would occupy nearly the full height and width of the host roof. The extension would therefore add substantial mass and bulk to the host property making it appear top heavy whilst also losing the traditional cat slide design. This would not be subordinate to the host property and would overwhelm the existing roof and harm the street scene as a result, contrary to the guidance in the SPD.

On my site visit I observed the adjoining No.44. I acknowledge that the proposal would result in increased symmetry between the handed pair given the extension to No.44 is essentially what the proposal is seeking to carry out. Evidently, the extension at No.44, along with others at No’s 54, 86 and 92 were carried out as permitted development. Since then, the Council has reconsidered its approach to these types of development, and the proposal before me was assessed against the development plan. I understand the appellant’s frustration at this situation, and it is not an ideal approach, but I must assess the proposal as it is presented to me and against the development plan.

While there is some merit to creating a more symmetrical handed pair of dwellings, to my mind this would not be enough to overcome the harm to the host dwelling and street scene. The result would be a matching pair which would still be out of character with the prevailing roof forms of the local area. Moreover, I disagree that the existing alterations to No’s 44, 54, 86 and 92, ‘set the character’ of the area. From my observations, they are still in the minority and allowing further development which I consider harmful would not be justified on this basis alone.

My attention is also drawn to an extension at No.[address] which was allowed on appeal1. The scenario above was determinative in that appeal and I have been provided with a copy of the decision letter, although I don’t have the plans before me. The Inspector in that case determined that the balancing of two adjoining properties justified the proposal, which would otherwise have been contrary to the development plan. That proposal would have had its own site specific circumstances, the full extent of which I am not aware. Moreover, from the limited information I do have, the Inspector determined that that approach was the “less worst option” and that many properties in that local area had been extended at roof level. As such, this has not been determinative in my assessment of the proposal before me, which I have assessed on its own merits.

To conclude, the proposal would harm the character and appearance of the host dwelling and the local area. This would be contrary to policies CDH01 and CDH05 of the Barnet Local Plan 2021 – 2036 (adopted March 2025) and D3 of the London Plan (adopted March 2021). These seek to ensure that extensions are subordinate to the existing building in terms of size, scale and/or height, and maintain or improve the appearance of the locality or street scene, among other things. The proposal would also be contrary to the guidance in the SPD.

There were no objections from occupiers of neighbouring dwellings, nor was any harm identified by the Council to living conditions of residents or parking. Be that as it may, a lack of harm would be neutral rather than weighing in favour of a scheme. As such these matters were not determinative in the assessment of this appeal. 1 Appeal Reference: APP/N5090/D/21/3282358

The proposal would conflict with the development plan as a whole, and there are no other material planning considerations which would alter this finding. The appeal is therefore dismissed.