Appeal 6004586

The appeal is dismissed.

Full planning permission was secured in 2024 for the demolition of existing dwelling and garage and erection of a 4-bedroom 8 x persons dwelling (reference 78540/APP/2024/229).

The appellant seeks to amend the elevations of the approved dwelling to accommodate the installation of new windows with obscure glazing on the flanks of the dwelling, the installation of a new dormer (referred to by the appellant as a mansard window) to the front of the house, and new Velux windows on the side and rear pitches of the roof.

The application form states that the development was started in January 2025. At the time of my site visit, construction had taken place.

The Council does not object to the installation of windows with obscure glazing on the flank elevations of the dwelling or the installation of Velux windows on the side and rear pitches of the roof. Based on the plans before me and my observations during my site visit, I have no reason to disagree with those findings.

Accordingly, the main issue is the effect of the front dormer window on the character and appearance of the host dwelling and surrounding area.

The appeal property comprises a 2-storey detached dwelling located within an area which has a varied character, resulting from dwellings of a variety of architectural styles and forms. Notwithstanding this, there is a broad uniformity and rhythm to the pattern of development in the immediate surroundings of the appeal site, with most dwellings detached or semi-detached and sited a consistent distance from Park Road. Dwellings generally use a consistent materials palette, and many have hipped roofs. The appeal property has a form and design which reflects these common features, albeit it is of a more modern and angular style than some properties in the surrounding area. I observed during my site visit that although there are examples of properties with rooflights within their front roofslopes, there are no front dormers visible within the surrounding area.

A curved eyebrow style dormer has been constructed on the front roofslope of the appeal property. The dormer is of a relatively small scale and sited centrally on the roofslope between the projecting hipped canted bays. The scale of the dormer allows clear spacing to be retained to the roof slopes, ridge line and eaves. Nevertheless, even though the alignment of the dormer corresponds with that of the windows at first floor level, it appears as a discordant and unduly prominent feature. This is primarily as a result of its design and form which contrasts starkly with and relates poorly to the modern, angular design of the host property. Consequently, notwithstanding that the property is neither listed nor located within a Conservation Area, the dormer detracts from its overall appearance and architectural composition.

While mature trees lining Park Road screen the dormer to an extent, it is visible in some views from [address]. It is also visible from Park Road. In these views, the dormer appears incongruous by reason of its design at odds with that of the appeal property.

I acknowledge that the absence of front dormers in the surrounding area does not necessarily mean that such development would be at odds with the character and appearance of the area. Nonetheless, in this case, for the reasons set out above, the design fails to harmonise with the host property, consequently appearing as a discordant feature in the street scene.

Accordingly, I conclude that the front dormer window has a harmful effect on the character and appearance of the host dwelling and surrounding area. As such, it is contrary to the relevant provisions of Policy BE1 of the Hillingdon Local Plan: [name] – [name] (2012), [name] 11, DMHB 12 and DMHD 1 of the Hillingdon Local Plan Part 2 – Development Management Policies (2020) and Policy D3 of the London Plan 2021. Among other things, these policies seek development which harmonises with and enhances local context, makes a positive contribution to and integrates with the surrounding area and has no adverse cumulative impact on the character, appearance of quality of the existing street or wider area.

For the reasons given above, 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. Therefore, the appeal should be dismissed.