Appeal 3358900

The appeal is dismissed.

Since the appeal was lodged, revisions have been made to the National Planning Policy Framework (the Framework) published in December 2024. Having reviewed the changes, I am satisfied that they do not affect the substantive matters of the appeal, and that proceeding without seeking further comments from the parties would not be prejudicial to their cases.

The main issue is the effect of the proposal on the character and appearance of the appeal property, the street scene and the surrounding area.

The appeal property is a detached house located in a street scene that is mixed in terms of the design and form of dwellings. Although roof styles vary, they generally comprise traditional pitched roofs. There are some two-storey properties with dormer windows, but these are set within a traditionally formed pitched roof.

The frontages within this part of [address] are generally open, and the dwellings behind visible in the street scene. The appeal property is particularly prominent, being sited at the end of a row of houses, next to an open green and footpath which leads to the road and dwellings to the rear.

The principle of extending the appeal property with a loft conversion, including six dormer windows and hip-to-gable roof extension, has already been established by the grant of planning permission under ref. 24/00272/HHA. The approved plans indicate that the height of the dwelling would increase by approximately 400mm, with a central roof ridge. This proposal involves altering the roof pitch from 45 to 60 degrees, and replacing the ridge with a ‘mansard’ style roof with a flat section. The appellant advises that, as a result, the dormer windows would not appear as prominent as those approved.

The approved scheme would result in a material change in roof form and a consequent increase in the mass of the dwelling. However, the proposal would further increase the bulk at roof level, and the introduction of a significant element of flat roof would appear incongruous on the building and in the street scene. It would create a ‘top heavy’ appearance to the building, and I am not persuaded that this would be offset by the reduced prominence of the dormer windows. The new flat-roofed form is not a style evident in the locality, and it would appear discordant alongside the more traditional pitched roofs which prevail.

The visual impact would be exacerbated by the prominent siting of the dwelling next to an open space, and views of the proposed roof form would be visible from a number of public points. I note the appellant’s view that other properties and mature trees obscure the side view of the dwelling until one is in close proximity, but this would not mitigate the visual impact of the extended building at closer range.

Policy CSTP22 of the [name] and Policies for Management of Development (as amended), 2015 (CS) requires development to demonstrate high quality design founded on a thorough understanding of, and positive response to, the local context, which in this case is primarily of pitched roofed dwellings.

This policy is supported by the [name] & Extensions Supplementary Planning Document, 2017 (SPD). The Council does not dispute that the individual dormer windows would accord with the design guidelines in that document. However, section 5.4 of the SPD advises that the main purpose of adding dormer windows is to bring daylight into the roof space, and that roof conversions and additions will only be acceptable where high quality design is employed, where additions are in scale with the existing roof, and where the addition does not spoil the existing roof form (paragraph 5.4.4). In this case, the scale of the proposal would harm the design and form of the roof.

I appreciate the purpose of the proposal, to create a larger area of the roof conversion with improved head height. Whilst the appellant advises that the approved design would result in very limited head height, on the basis of the information provided I am not persuaded that this would render the space impractical, as suggested. Whilst the space created may be more restricted than the existing bedrooms, the approved floor plans and sections do not suggest that it would be functionally unusable. The improvements to the accommodation would not justify the compromise in the design quality and its visual impact.

The appellant has supplied photographs of the array of roof styles in the vicinity, and these were visible at the appeal site visit. I agree that there is a diverse mix and no dominant architectural style to which the appeal property should adhere. However, none of the examples obviously include a large area of flat roof in place of a more traditional ridge, and the introduction of this incongruous roof style would be unduly disruptive in the street scene.

The appellant has drawn attention to examples of dormer windows which exceed the Council’s size guidelines, although I note that some are more successfully integrated in the street scene than others. In the absence of any details of the permissions granted for these developments, I do not know the policy frameworks against which they were assessed, or if they pre-date the adoption of the SPD. In any event, as it is the specific design and form at issue in this appeal, these developments offer little support to the appeal.

I therefore conclude that the proposal would detract from the character and appearance of the appeal property, the street scene and the surrounding area. It would conflict with the design requirements of the Framework, to ensure that developments are visually attractive as a result of good architecture and sympathetic to local character, including the surrounding built environment; and contrary to [name] CSTP22 and PMD2, which requires development to contribute positively to the character of the area, and guidance in the SPD.

For the reasons given above the appeal should be dismissed.