Appeal 3277588

The appeal is dismissed.

The site visit was undertaken by an Appeal Planning Officer whose recommendation is set out below and to which the Inspector has had regard before deciding the appeal.

The Government published on 20 July 2021 a revised version of the National Planning Policy Framework. [name] have had regard to the revised national policy as a material consideration in my decision-making, planning decisions must still be made in accordance with the development plan unless material considerations indicate otherwise. In this instance, the issues most relevant to the appeal remain unaffected by the revisions to the Framework. I am therefore satisfied that there is no requirement to seek further submissions on the revised Framework, and that no party would be disadvantaged by such a course of action.

The appeal property falls within the Osterley Park Conservation Area (the ‘CA’). Therefore, the main issue is the effect of the proposal upon the character and appearance of the host property and whether it would conserve and enhance the character CA.

No. 15 is a two-storey semi-detached dwelling located at the end of a cul-de-sac on [address]. It is symmetrically paired with No.16. The surrounding area is residential, and the distinctive character is derived from two-storey symmetrically paired, semi-detached dwellings, predominantly with hipped roofs. [address] is a long street with some existence of roof extensions and alterations along its length, there is general uniformity on the street. A larger percentage of properties still retain their original hipped roof. These prominent features create the appearance of a neat and unified street scene.

London Borough of [name] Planning Document (2017) (the ‘SPD’) states that the Council will normally refuse permission to convert sloped hip-end roofs into flat-end gable roofs because it would unbalance the appearance of the pair of semi-detached houses. The appellant has presented a number of photographs where roof extensions have created a slightly unbalanced pair such as nos. 3, 10 and 12A. Neither party has provided specific information relating to the background to those examples, including whether they have planning permission or when they were constructed. They possibly could have been constructed enabled by permitted development rights and as such were not subject to the assessment of a formal planning application. As observed on visit to the site, they also appear to be of some vintage and would have been completed prior to the incorporation of [address] into the Osterley Park Conservation Area in January 2020 and therefore are likely to have been subject to different planning considerations.

There are also examples of pairs of symmetrically paired semi-detached properties which have gable roofs at nos. 56 and 57 and 18 and [address]. These are in line with guidance in the SPD which advises that where the adjoining property has an existing lawful extension, it may be possible to rebalance the appearance of the pair by building a similar extension. That is however not the case with the appeal property and its adjoining neighbour.

Nonetheless, in the main, two-storey semi-detached pairs with hipped roofs are a distinguishing feature. Notwithstanding some diversity therefore, the architectural integrity of the street scene remains largely intact and the uniformity in design is an attractive feature of the area. Consequently, the other examples referred to do not amount to a justification for the harm that would arise from the proposal in this instance.

The extension would involve the formation of a hip to gable roof enlargement extending to match the ridgeline of the existing roof which would substantially increase the mass and volume of the existing roof and would not appear subordinate to the existing property. The scale and design of the resulting roof, including the box-like proportions of the substantial rear dormer, would be noticeably greater than that of the other paired dwellings in its immediate vicinity of [address].

This would introduce an incongruous roof form into the otherwise symmetrical pair of properties and would result in an alien form of development in the context of the design of surrounding properties as described above. The contribution that the host property and adjoining dwelling make to the appearance of the street scene would be diminished as a result. The roof-form, scale and design of the development would appear out-of-keeping with the external appearance of the dwelling and the form of the extension would be visually harmful to the area’s established symmetrical character.

I find that the development would significantly harm the character and appearance of the host property and the street scene. Accordingly, it would fail to conserve or enhance the character of the CA and conflicts with the aims and objectives of policies CC1, CC2, CC4 and SC7 of London Borough of Hounslow’s Local Plan 2015-2030 (2015) and the National Planning Policy Framework which seek amongst other things to ensure that all new development conserves and takes opportunities to enhance the significance of the borough’s heritage assets as a positive means of supporting an area’s distinctive character.

For the reasons given above and having had regard to all other matters raised, I recommend that the appeal should be dismissed. Ifeanyi Chukwujekwu APPEALS PLANNING OFFICER

I have considered all the submitted evidence and the Appeal Planning Officer’s report, and on that basis, I agree with the recommendation and shall dismiss the appeal. [planning inspector] INSPECTOR.