Appeal 3276585

The appeal is allowed and planning permission is granted for a two storey side extension, single storey side/rear extension and conversion of roof space to habitable use to include a rear dormer and 2 front rooflights at [site address] in accordance with the terms of the application, Ref 16101/APP/2021/838, dated 3 March 2021, subject to the following

The development hereby permitted shall begin not later than 3 years from the date of this decision.

The development hereby permitted shall be carried out in accordance with the approved plans: KR10-AP1-101, KR10-AP1-102, KR10-AP1-103.

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

I have used the Council’s description of the development in reaching my decision as it more fully describes the details of the development than that given on the original planning application form. The appellants appeal form also makes reference to the updated description. I shall determine the appeal on this basis accordingly.

The main issue is the effect of the proposed two storey side extension and roof extension on the character and appearance of the host property and the area.

The appeal property at No. [site address] (No. 10) is a two storey semi-detached dwelling with a single storey utility/garage extension at the side and conservatory at the rear. It is located in a mature well-established residential cul-de-sac, characterised by semi-detached properties set back from the road behind a front garden/driveway. A number of the dwellings have two storey side extensions and roof extensions of varying styles and designs that generally appear as clearly subordinate to the dwellings.

The appeal site has an extensive planning history relating to proposals to extend the property. The proposal would involve the construction of a two storey side extension that would be set back from the front elevation and stepped down below the ridge of the main house with a pitched hipped tiled roof. The proposal would also involve the construction of a single storey flat roofed side/ rear extension and a loft conversion with a rear dormer and front rooflights.

Policy DMHD1 of the Hillingdon Local Plan Part 2 Development Management Policies 2020 states that two storey side extensions and roof extensions should be subordinate to the main dwelling. Policy DMHD1 specifies two storey side extensions should not exceed half the width of the original property in order to appear subordinate to the main dwelling and should have a minimum set back of at least 1m from the side boundary in order to give visual separation from adjoining properties.

In this case, the proposed first floor element of the side extension would be more than half the width of the original property. It would be set-in about 1m from the side boundary and would be separated from the adjacent property at No. 11 by a garage, pedestrian access and driveway running between the properties. The adjacent two storey property at No. 11 is also set back and set down below No. 10 due to the staggered built form of the properties and gently sloping topography of the site and the surroundings.

The appeal property is on a relatively spacious plot and as such the extensions would not appear overlarge, relative to the overall plot size. Given the site’s location, the proposed side extension would only be visible over short distances when passing the site. The rear flat roof dormer extension would be inset from the edges and eaves of the roof and set down below the ridge line of the host property. The proposed extensions would be seen in the context of the current varied architectural styles of the existing extensions and alterations to the side and rear of the appeal property and the surrounding properties together with the staggered built frontage and changing site levels within the locality.

Against this backdrop, the scale, form and design of the proposed two storey side extension and rear dormer extension would not appear significantly out of place or excessive in relation to the built form of the host property and the relationship with the adjacent properties would allow reasonable space to allow visual separation from adjoining properties.

The overall scale and proportions of the proposed side extension and rear dormer, set back and stepped down, together with the use of matching materials and fenestrations would ensure the proposal would sit relatively unobtrusively against the two storey form and hipped roof of the main property. The proposed development would therefore achieve an appropriate degree of subordination to the host property and as such would limit any significant adverse impacts on the street scene.

Consequently, I conclude that the proposed two storey side extension and roof extension would not adversely harm the character and appearance of the host property and the area. It would be consistent with the overall design aims of Policy BE1 of the Hillingdon Local Plan: Part 1 [name] 2012 and Policies DMHB11, DMHB12 and DMHD1 of the Hillingdon Local Plan Part 2 Development Management Policies 2020. These policies, amongst other things, seek to ensure that development proposals, including residential extensions, will be of a high standard of design that harmonise with the local context and make a positive contribution to the local area in terms of layout, form, scale and materials.

Having regard to the National Planning Policy Framework, and in particular paragraph 56, in addition to the standard time limit condition, I have specified the approved plans as this provides certainty. In order to protect the character and appearance of the area, I have imposed a condition requiring matching external materials.

For the reasons given above and having considered all other matters raised, I conclude that the appeal should be allowed.