Appeal 3333501

The appeal is dismissed.

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

The host and No 49 form a semi-detached pair. It is set back from the road amongst other similarly styled pairs on this stretch of [address]. Some of the houses have had their original hipped roof extended to form a gable. Additionally, as illustrated by the photographs in the appellant’s statement, a few have two storey side extensions, but these are typically either set well down from the host’s ridge, set well back from its front face, or have a hipped roof.

Notwithstanding those examples and a mix of facing materials, given their fairly regular spacing and their broadly similar form and proportions, the properties have a fairly consistent and cohesive appearance in the streetscene.

The proposed side extension would be set back 0.5 metre from the host’s principal front face at first floor level, but as it would be only marginally set down at roof level, it would not achieve a fully subordinate appearance. Moreover, whilst its gable would match the host’s existing gabled form, it would be at odds with the building’s original appearance and with the retained hipped roof at No 49.

Considered together with the existing hip to gable extension, the resultant property would have markedly longer proportions across its front face at first floor and roof level compared to its attached neighbour. The scheme would thus further unbalance this semi-detached pair.

As [address] has an attached single storey garage and the house retains its original hipped roof, the proposed side extension, which would be built up to the boundary with that property, would not give rise to a significant terracing effect. However, given its form, scale and bulk, the resultant property would also appear at odds with that typical semi-detached house, and it would disrupt the rhythm and grain of development in the streetscene.

The harmful impacts would continue in private views to the rear. Considered cumulatively alongside the existing hip to gable extension, the large rear dormer which covers almost all of the extended roof, and the large conservatory, the proposal would overwhelm the original property, such that very little of its original form and style would remain.

For these reasons, notwithstanding the proposed use of matching materials and matching fenestration, the scheme would significantly harm the character and appearance of the host property and the area. It would therefore conflict with that part of Policy DMHD 1 of the Hillingdon Local Plan Part Two: Development Management Policies (2020) (‘HLPP2’) which states that extensions should appear subordinate to the main dwelling and should respect its original design.

Additionally, whilst the two storey side extension would be less than half the width of the original property, it would conflict with Policy DMHD 1’s stance that it should be set in a minimum of 1 metre from the side boundary and a similar distance behind the main front elevation. That policy also states that a two storey side extension will not be supported where a hip to gable roof extension already exists, as is the case here.

It would also fail to comply with Policy BE1 of the Hillingdon Local Plan Part One: [name] (2012), and HLPP2 [name] 11 and DMHB 12. In general terms these require high quality design which improves and maintains the built environment and local distinctiveness, harmonises with the local context and streetscene, and complements townscape character, having regard to matters such as rhythm, scale, form, height and bulk.

Finally, although the scheme would optimise the use of the site, as it would not be sympathetic to local character, it does not find support from the National Planning Policy Framework when considered as a whole.

Having regard to all other matters raised, the appeal is therefore dismissed.