Appeal 3320967

The appeal is allowed and planning permission is granted for a two storey side extension with a hipped roof together with a rear conservatory at [site address] in accordance with the terms of the application, Ref: 70839/APP/2019/3908, dated 27 December 2019, subject to the following

Other than as required by condition No. 2 below, the development hereby permitted shall be carried out in accordance with the following approved plans: TAC 3129-305 (Site location plan), TAC 3129-900 (As built/proposed ground floor layout), TAC 3129-901 (As built/proposed first floor layout), TAC 3129-903 (Proposed loft floor) and TAC 3129-905 (Proposed elevations).

This permission shall not include the rear dormer window as depicted on the approved plans.

The materials to be used in the construction of the external surfaces of the development shall match those used in the existing building.

An application for costs was made by [name] against the Council of the London Borough of Hillingdon. This is the subject of a separate decision.

In 2015 planning permission was granted for a two storey side extension to the property (Ref: 70839/APP/2015/1736). However, rather than having a hipped roof as approved, the extension was completed with a gable end. An application for the retention of that development was refused, and a subsequent appeal dismissed (Ref: APP/R5510/D/19/3222195) (‘previous appeal’).

A Lawful Development Certificate was also approved at the property for the proposed conversion of the roof space to habitable use including a rear dormer, rooflights and a hip to gable conversion (Ref: 70839/APP/2015/1551). However, the Council contends that as those works appear to have been carried out as one operation with the side extension, they were not lawful. I have limited evidence on this matter, and the lawfulness or otherwise of those works is not before me as part of this appeal.

The principal parties agree that the scheme the subject of this appeal is for the retention of the rear conservatory, and a two storey side extension. As now proposed, that side extension would have a hipped roof. Additionally, as the proposed side extension would attach to the existing hip to gable extension in the main part of the house, I have considered the planning merits of that gable extension in my decision.

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

The host forms one half of a semi-detached pair, which is prominently located at an angle to the junction of [address] and [name]. Nearby properties on these two roads are also mostly two storeys high, and are arranged in semi-detached pairs or short terraces. Some have two storey side extensions, and the vast majority of the buildings end with a hipped roof.

Policy DMHD 1 of the Hillingdon Local Plan Part Two: Development Management Policies (2020) (‘HLPP2’) states that extensions should appear subordinate to the main dwelling, and should respect the design and materials of the original house. It continues that side extensions should be set in at least 1 metre from the side boundary and, on corner plots, should ensure that the return building line is not exceeded. It also states that where hip to gable roof extensions exist, two storey side extensions will not be supported.

The two storey side extension as proposed would project towards [name], but would be set in, and angled away, from the pavement, thus maintaining a gap to the side. Although it would be closer to the highway than the line of houses on [name], there is a significant distance to them, and that relationship can also be said of the extended property on the opposite corner of the junction at [address] (‘No 149A’).

Whilst the side extension as constructed has an incongruous and overbearing impact, altering its roof to a hip would significantly reduce its scale and bulk. The proposed roof would be set down compared to the host, the extension’s front and rear faces would be set well in, and it would be faced in matching materials. Moreover, constructing the extension with a hipped roof would better respect the form of the original house, along with the character of most nearby buildings, including the other half of this pair, and the extended building at No 149A.

On this matter, I therefore concur with the Inspector in the previous appeal, including the finding at paragraph 9 of that decision, that the proposed hipped roof would not look awkward seen against the host’s existing gable end.

The rear conservatory, which is already in place, is a fairly large structure, which is clearly visible from [name] above a boundary fence. However, its lightweight construction limits its impact, and in those views, it is seen against the backdrop of the host and the buildings beyond.

I therefore conclude that the proposed two storey side extension with a hipped roof, when considered together with the existing rear conservatory, and the hip to gable extension in the main part of the house, would not harm the character and appearance of the host property or the area.

Amongst other things, and in general terms, Policy BE1 of the Hillingdon Local Plan Part One: [name] (2012), HLPP2 Policy DMHB 11, and Policy D4 of the London Plan 2021 require development to achieve a high quality design which improves and maintains the built environment, and harmonises with the streetscene and complements the character of the area, having regard to matters such as building lines, scale and bulk. The scheme would not conflict with that approach.

There would be a conflict with HLPP2 Policy DMHD 1, particularly as the return building line would be exceeded and given that the two storey side extension would attach to a hip to gable extension in the main house. Nevertheless, for the above reasons, the development would not harm the character, appearance or quality of the existing street and area; it would appear suitably subordinate to the main dwelling; and it would appropriately respect the design of the original house. The scheme, as proposed, would therefore accord with the development plan when considered as a whole, and the appeal will be allowed.

Turning to the matter of conditions, as the development has already been started, the suggested time limit for commencement is not appropriate. However, in the interests of certainty, a condition is necessary requiring that the development be carried out in accordance with the approved plans. For clarity, condition No 1 therefore lists the approved plans, whilst condition No 2 confirms that this does not include the rear dormer window. Finally, in the interests of good design, a matching materials condition is necessary.

I conclude that the scheme as proposed would not harm the character and appearance of the host property or the area. Consequently, having regard to all other matters raised, including a representation by an interested party, the appeal is allowed.