Appeal 3352381

The appeal is dismissed.

The site visit was undertaken by a representative of the Inspector whose recommendation is set out below and to which the Inspector has had regard before deciding the appeal.

The reason for refusal on the Council’s decision notice relates to matters of character and appearance. The Council’s officer report confirms that the site is situated within a conservation area. After seeking clarification during the appeal process, the Council has confirmed that the site is situated within the Weller Estate Conservation Area. There is a duty imposed by Section 72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990 requiring decision makers, in the exercise of planning functions, to have special regard to the desirability of preserving or enhancing the character or appearance of a conservation area. I have therefore had regard to this in defining the main issue. The appellant has also been provided with an opportunity to comment on the relevance of the Weller Estate Conservation Area to the proposal and the comments received have been taken into consideration.

The main issue is whether the proposal would preserve or enhance the character or appearance of the Weller Estate Conservation Area (the CA).

The CA partly derives significance from its 1930s suburban housing and layout that is primarily comprised of semi-detached pairs of various symmetrical designs, many of which embody the ‘Metroland’ aesthetic. The leaflet describing the significance of the CA (Published 1995) sets out that the design of the houses is the single most important part of the area’s identity and describes their predominant design elements such as great areas of sloping roofs, leaded windows, open porches, as well as highly standardised plot sizes and clear building lines fronting straight roads. Such features contribute to a very regular pattern of development with a high-quality residential character. Indeed, the Council indicate the site is located in an Established Residential Area of Special Character (ERASC).

The appeal dwelling and [address] (No 113) form a semi-detached pair that is characterised by a great deal of symmetry and cohesiveness. This is achieved by their similar scales, corresponding front bay windows, arched main entrances and central chimneys. They also share a distinctive, steeply sloping roof form with modest dormer windows to the central front and rear roof slopes. Each property also has a side-facing gable feature that is set down from the main ridgeline, which further distinguishes its balanced roof profile. There have been some alterations, such as a rear extension and garage conversion at the appeal site. However, these changes are not so pronounced that they detract from the appreciation of the pair’s original design. Consequently, the semi-detached pair positively contribute to the character and appearance of the CA.

The Chiltern and [name] (2017) (the TCS) identifies the site as being within a ‘[name] character typology, which is defined by the buildings that line the roads rather than the landscape that surrounds them. This document identifies that threats to this character typology include the development of semi-detached houses that creates visible differences between the two halves of the property.

From the front, the bulk of the first-floor gable extension together with its painted render finish and large window would not integrate well with the profile or materials of the host dwelling’s roof. The proposal would also project forward of the modest dormer windows on the semi-detached pair and would detract from their appreciation as a central and cohesive design feature. In addition, the proposed gabled porch would extend incongruously above the eaves.

The overly dominant scale of the front elements including the mismatch of roof forms would detract from the sloped roof profile and symmetry that is characteristic of the appeal pair and other semi-detached pairs in the CA. Consequently, the extensions would have an unbalancing effect which would appear inharmonious in the wider street scene, eroding the high-quality character and appearance of the CA and ERASC. It would also be at odds with the TCS’s ‘Planning and [name]: [name], specifically that the redevelopment of semi-detached houses must ensure coherence between the two halves of the property.

At the rear, for similar reasons the scale and design of the proposal would also unbalance the pair, in particular their roofscape, which adds to my concerns above. While public vantage points of the rear of the proposal would be limited, it would still be appreciable from neighbouring gardens where its uncharacteristic design would be viewed as a discordant addition to the appeal pair and the CA.

Even if elements of the proposal accord with some of the general guidance contained in the Council’s Residential Extensions and Householder Development Supplementary Planning Document (2013) (SPD), the SPD sets out that an important goal for any extension should be to harmonise with a building, striking a balanced visual relationship with its existing features and integrating in such a way that it does not adversely affect the character and appearance of the locality. For the reasons set out, the proposal would not meet this objective.

My attention has been directed to extensions at the unattached neighbour, [address] (No 109). I also acknowledge that there are other extensions in the area that have, to a degree, unbalanced the overall forms of their respective semi-detached pairs. However, they are not representative of the overriding cohesion that characterises much of the housing in the CA, including the positive contribution that the symmetry between the appeal dwelling and its semi-detached counterpart at No 113 makes to the character and appearance of the CA.

Several other dwellings in the area are also referred to in the appellant’s ‘[name] and their further comments dated 9 April 2025. The appellant contends that the Council has not followed its design guidance in those cases. However, the full details of these developments are not before me, and so I cannot be certain of the context in which they may have received planning permission. Nevertheless, from the evidence before me, there are discernible differences between the examples provided and the appeal scheme. Furthermore, even if development that has taken place elsewhere does not positively contribute to the significance of the CA, this does not justify the appeal development having regard to the site-specific harm identified and the duty to preserve or enhance the CA.

For the reasons given above, the proposal would not preserve or enhance the character or appearance of the CA. Due to the scale of the proposal, it would result in less than substantial harm to the significance of the CA. Paragraph 215 of the National Planning Policy Framework (the Framework) indicates that this harm should be weighed against the public benefits of the proposal. The evidence before me suggests that the proposal would improve the thermal properties of the dwelling. However, this is a modest benefit to a single household. No substantive public benefits have been put forward to outweigh the harm to the CA, and I apply great weight to the conservation of the CA in line with Paragraph 212 of the Framework.

I conclude that the proposal would not preserve or enhance the character or appearance of the CA. It would be contrary to Policy CS20 of the [name] for Chiltern District (2011) and Policies CA1, CA2, GC1, H15 and H13 of the Chiltern District Local Plan (adopted September 1997, including alterations adopted May 2001, consolidated September 2007 & November 2011), which require that new development is of a high standard of design, and that extensions respect the scale, proportions, form and design details of the existing dwelling, and preserve or enhance the character or appearance of the CA.

For the reasons set out, the proposal would also conflict with the requirements in the Framework to conserve and enhance the historic environment. It would also fail to reflect the National Design Guide 2019 which sets out that well-designed places are integrated into their surroundings so they relate well to them.

Concerns have been raised regarding a lack of communication from the Council during the application stage. However, these concerns do not relate to the planning merits of the appeal scheme, which must be the focus of my recommendation.

The proposal would be contrary to the development plan. For the reasons given above and having had regard to all other matters raised, I recommend that the appeal should be dismissed.

I have considered all the submitted evidence and my representative’s report and on that basis the appeal is dismissed.