Appeal 3334238

The appeal is dismissed.

The amendments of the National Planning Policy Framework were published in December 2023. These amendments do not alter the basis upon which this appeal has been assessed.

It is considered that the main issue is the effect of the proposed development on the character and appearance of the host property and the surrounding area.

The appeal property is a 2-storey dwelling at the end of a terrace properties and possesses a hipped roof. As an original part of the dwelling’s design, there is a 2-storey projection at the rear of the property which possess a hipped roof. These design characteristics are shared by [address] which is at the other end of the terrace. Although a separate semi-detached dwelling, No. 34 which neighbours the property has been extended at roof level and possesses both a rear dormer and gable roof form. The rear elevations of the terrace and No. [address].

A further design feature of the terrace is that there is a front projection associated with Nos. 28 and 30 and this also possesses a hipped roof. This is a visually dominant feature of the terrace. Only a limited number of similarly designed terraces were observed within the surrounding area during the site visit and they make a positive contribution to the streetscenes.

The proposed development includes roof extensions which would result in hipped to gable roof forms for the main roof and the roof above the 2-storey rear projection would also have higher ridge height and be asymmetrical in design. Whether these alterations to the roofs could be undertaken as permitted development is not a matter for determination as part of this appeal.

As identified by the Council, the proposed hip to gable extension of the main roof would result in an unbalancing of the symmetrical appearance of the terrace. This alone would not be a reason for this appeal to fail but when considered cumulatively with the visually dominant front hipped roof feature, the form and additional bulk of the proposed gable roof would have a significantly harmful impact on the character and appearance of the host property and the terrace when viewed from [address]. The existence of the gable roof of No. 34 does not alter this assessment.

[address] the proposed asymmetrical gable roof of the 2-storey projection would be seen alongside the alteration to the property’s main roof. The ridge height of the roof would be increased to match the main roof. These alterations to the design, height and form of the property’s rear roofs would result in the 2-storey projection possessing a visually dominant appearance which would have a detrimental effect on the character and appearance of the host property and terrace when viewed from [address]. This adds to the significant harm which has already been identified.

There would be an adequate separation between the resulting appeal property and No. 34 to maintain their separate identities when viewed from the road but this does not outweigh the significant harm which has been identified.

Reference has been made by the appellant to 3 dwellings within the surrounding area where alterations have been made but the detailed planning circumstances of these other dwellings have not been provided. Further, it was also noted that, where relevant, these dwellings were not located within a terrace sharing the same design as the one within which the appeal property is located. Accordingly, limited weight is given to these other dwellings in the determination of this appeal.

For the reasons given, it is concluded that the proposed development would cause unacceptable harm to the character and appearance of the host property and the streetscene and, as such, it would conflict with Policies BE1, DMHB 11, and DMHD 1 of the Hillingdon Local Plan (HLP). Amongst other matters these policies require development, including extensions, to be of a high quality of design, including by reason of scale and architectural composition, and for rear extensions not to create a dominant appearance out of scale with the rest of a building.

HLP Policy DMHB 12 concerns streets and public realm rather than the design of household extensions. Policies D3 and D4 of the London Plan are primarily directed at optimising site capacity through the design-led approach and the design requirements for larger schemes rather than the design of extensions. However, although these policies are not of direct relevance, for the reasons given it is concluded that this appeal should be dismissed.