Appeal 3356536

The appeal is dismissed.

Planning permission has recently been granted for a dormer extension on the main rear roof slope of No 46 together with roof lights at the front and side of the dwelling. The appellant seeks to amend the approved scheme by replacing the dormer window with French doors and, from the plans before me, by installing an external glass screen to prevent falls.

At the time of the site visit, the new French doors and screen were in place. These appear to have been installed broadly in accordance with the submitted plans.

On 12 December 2024, a revised National Planning Policy Framework (the Framework 2024) was published with an amendment issued on 7 February 2025. The Framework 2024, as amended, does not raise any new matters that are determinative to the outcome of this appeal.

The main issue is the effect of the French doors and screen on the character and appearance of the host building and the local area.

The appeal property is a 2-storey end terrace house in a predominantly residential area. It falls within the Magdalen Park Conservation Area (CA), which derives its significance as a designated heritage asset largely from two formally laid out and well-preserved interwar housing estates, which are Openview and Fieldview. Key features of these estates include the orderly arrangement of properties, roads and open spaces together with the broadly consistent appearance of the buildings within it. I have paid special attention to the desirability of preserving or enhancing the character or appearance of the CA as required by section 72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990, as amended.

The addition of full-length rear facing windows to the dormer has introduced a visually strong vertical feature at a high level on the host property. This arrangement conflicts unsatisfactorily with the modest size and the horizontal emphasis of the first-floor windows below. As a result, the windows, as installed, unduly disrupt the pattern and hierarchy in the fenestration in the rear façade, which is a distinctive feature of the original building. The external glass screen that is affixed to the rear of the dormer exacerbates this harmful visual impact. As an unfamiliar feature of most dwellings within the CA, the presence of this feature draws the eye. In doing so, it reinforces the incongruity of the French doors. As a result, the appeal scheme spoils the intrinsic character of the original dwelling.

Public views of the French doors and screen are limited given their position at the back of the house, and away from the road. Nevertheless, these features are evident from gardens of nearby properties from which the uneasy relationship between the new full-length windows and those below would be evident. In these views, the French doors and screen would appear as discordant elements at the rear of No 46 and therefore unwelcome additions to the local area. As such, the appeal scheme fails to preserve the character and appearance of the CA.

I appreciate that the new dormer windows are a little longer than those on the first floor. However, for the reasons given, their visual impact is greater than might be implied by a comparison between the size of these windows. Furthermore, the visual effect of the French doors and screen is to visually accentuate the presence of the rear dormer. As a visually dominant feature in the rear roof scape of No 46, the dormer could not reasonably be described as subservient to the original building, which is expected of rear extensions under Policy LP5 of the Wandsworth Local Plan 2023-2038 (LP).

The appellant states that the loft conversion is smaller than those of some nearby properties and I saw that several dwellings include rear dormers with sizeable windows, some of which are visible from the site. Few background details of these cases have been given and so I cannot be certain that the circumstances of these examples are the same or very similar to those of the development sought. To my mind, these examples have respected the appearance of the host building and blended into the character of the local area with varying degrees of success. Therefore, the cases do not necessarily set a desirable precedent to follow. In any event, each development should be assessed on its own merits, which I have done.

On the main issue, I therefore conclude that the development causes significant harm to the character and appearance of the host building and the local area. It is therefore contrary to [name] LP1, LP2, LP3 and LP5 and the Council’s Supplementary Planning Document, Housing. These policies and guidance aim to ensure that residential extensions and alterations respect or complement the form of the host building, are not overly dominant, and sustain, preserve or enhance any

The Framework 2024 states that when considering the impact of a proposal on the significance of a designated heritage asset, such as a conservation area, great weight should be given to the asset’s conservation. Given the modest scale of the development relative to the considerable size of the CA, the identified harm would be less than substantial. In those circumstances, the Framework 2024 states that the harm should be weighed against the public benefits.

In this case, the French doors would allow more natural light to penetrate the roof space compared to their approved counterparts. A lighter and more airy roof space would provide a more appealing room within which the appellant’s daughter could study. It could also encourage other health benefits to users. However, these are mainly private benefits. No specific public benefits have been put forward and none would outweigh the significant harm that I have identified.

An interested party raises additional concern in relation to the effect of the development sought on privacy. This is an important matter, and I have considered all the submitted evidence. However, given my findings on the main issue, this matter has not been critical to my decision.

The appellant is critical of the Council’s handling of the application, notably in their delayed responses to enquires and is disappointed by the lack of constructive feedback on the proposal. However, my remit is solely to determine this appeal.

Overall, the level of harm caused by the development sought on the host building and the CA is significant. The public benefits do not outweigh this harm. As such, the planning balance is tipped against the appeal scheme.

The development sought conflicts with the development plan, when read as a whole. There are no material considerations, including the Framework 2024, 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.