Appeal 3347201

The appeal is dismissed.

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

The host, together with No 177, form a well-balanced, simply proportioned, semi-detached, hipped-roofed pair, sited towards the end of [address]. Next to it, at 181 and [address] (‘Nos 181/183’) lies a similarly well-balanced, semi-detached pair with a gabled roof, and with large rectilinear dormers covering most of the rear roof.

Elsewhere along [address] the dwellings are generally two storeys tall and arranged as semi-detached pairs or short terraces, some with front gables or bay windows typical of their era. Their rear elevations on this side of the road face the [name], from where varied extensions are clearly visible, resulting in a somewhat less cohesive appearance compared to the streetscene.

The proposed side extension would have a set back front wall at first floor and a set down roof, which would provide a degree of articulation, and ensure that it would have a largely subordinate appearance to the host. However, considered together with the proposed hip to gable conversion, it would unbalance this pair in the streetscene.

To the rear, the proposed dormer would cover much of the extended roof from marginally below the host’s ridge to just above its eaves. In combination with the proposed side extension, the two storey rear extension, and a single storey extension, the development would overwhelm the original property, such that very little of its original form, scale and style would still be legible.

Viewed from the open space, the resultant property, with its gabled, hipped, and cat-slide roof form, and a substantial flat-roofed dormer, would have a very eclectic appearance. It would be visually complex and awkward, and markedly at odds with No 177, thus causing a significant imbalance in the pair. I have no drawings of the unimplemented planning permission at No 177 (Ref: 77560/APP/2022/2961), but based on the decision notice, that development would be significantly less extensive than proposed here.

It would also jar with the more modest scale and simpler proportions of the pair at Nos 181/183. Some other nearby properties along this stretch of [address] have also had rear dormers, and some have had single or two storey rear extensions. As illustrated by the appellant’s photographs, that includes matching two storey hipped roofed rear projections to the hipped roofed semi-detached pair at Nos 165 and 167. However, none that I observed have had such a visually discordant and overwhelming combination of extensions, that would cause such an imbalance with its attached neighbour, as those proposed here.

For these reasons, notwithstanding the proposed use of matching materials, the scheme would significantly harm the character and appearance of the host property, the semi-detached pair, and the area. It would therefore conflict with Policy DMHB 11 of the Hillingdon Local Plan: Part Two Development Management Policies (2020) (‘HLP2’), Policy BE1 of the Hillingdon Local Plan: [name] (2012), and Policy D3 of the London Plan 2021.

Amongst other things, and in general terms, these require high quality design, which improves and maintains the built environment and local distinctiveness, harmonises with the local context and the streetscene, and complements townscape character, having regard to matters including rhythm, scale, form and bulk.

It would also conflict with those parts of HLP2 Policy DMHD 1 which state that overly large roof extensions including proposals to convert a hipped roof to a gable will not be supported; and more generally with its stance that extensions should appear subordinate to the main dwelling and should respect its original design, having regard to cumulative impacts.

For these reasons, and having regard to all other matters raised, the appeal is dismissed.