Appeal 3307765

The appeal is dismissed.

The main issues are the effect of the proposed development on: a) the living conditions of neighbouring residents; and b) the character and appearance of the host property and surrounding area.

No. [site address] (no.92) is one of a pair of semi-detached dwellings located within a predominantly residential area. The adjoining property of no. [address] (no. 90) has already been extended to the rear through a part single, part two-storey extension.

The proposal would extend beyond the rear of the appeal property to a comparable depth as the rear extension that has been undertaken to no.90. However, whereas the neighbouring property’s extension, is single storey alongside the shared boundary, the appeal proposal would introduce a two-storey element alongside this boundary line.

The proposed extension would sit in close proximity to a rear, first floor, bedroom window serving no. 90. An existing two-storey extension to no. 94 sits on the other side of the relevant first floor bedroom window. Together, the appeal proposal alongside the neighbour’s existing extension, would lead to a tunnelling effect on the rear bedroom window. The overall depth and height of the proposed extension, alongside its relationship with the existing built form at no. 90 would therefore result in a harmful overbearing impact and loss of outlook and light from the rear bedroom of the neighbouring property. This is despite the proposed extension being designed to taper away from the shared boundary.

I note that there is dispute between the main parties as to whether the proposal adheres to the ‘45-degree rule’ as set out in the Council’s Residential Extensions & Alterations Supplementary Planning Document (SPD) (adopted 2011). Even if it does comply with the 45-degree rule, the approach set out in the SPD remains guidance, while consideration still needs to be given to an individual development’s site-specific context and potential impacts. In this instance, I find that the proposal would remain harmful irrespective of whether it complies with the 45-degree rule.

The development would be set some distance off the boundary with no. [address] (no. 94). This greater distance, together with the intervening detached garage in the back garden of no. 94, would mean that the proposal would not have a harmful overbearing effect or loss of light to either the garden or habitable rooms of that property.

For the foregoing reasons I conclude that, whilst the proposed development would not cause harm to the occupants of no. 94, it would have a harmful effect upon the living conditions of the occupiers of the neighbouring residential property at no. 90, with particular regard to outlook and loss of light.

The proposal therefore conflicts with Policy DE1 of the Swindon Borough Local Plan 2026 (adopted 2015) (the Local Plan). The policy, amongst other matters, seeks to ensure that the design of development proposals take account of amenity considerations, including outlook and light.

It would also not comply with the aims of the National Planning Policy Framework (the Framework) or the SPD, which together, amongst other matters, seek to ensure that developments promote a high standard of amenity.

There are a variety of house types in the surrounding street scene, albeit those within the immediate vicinity of the appeal site primarily tend to be semi-detached, and many appear to have been extended or altered.

The proposed extension would incorporate materials that would be in keeping with the host dwelling, whilst the design would also reflect existing elements, such as, through the use of a hipped roof. The depth of the proposed extension would also align with an existing single storey element at the rear of the property. However, despite being set down from ridge height, the proposed full width two-storey rear extension would be of a scale, bulk, and massing that would add an unduly dominant element and would be at odds with the scale of the existing dwelling.

I appreciate that given the proposed extension is to the rear of the property it would have a general lack of prominence within the streetscene. However, it would remain clearly visible from several neighbouring properties and their gardens.

The appellant contends that the proposed extension is of a size and design widely approved by the Council throughout the borough, albeit has provided no specific evidence to verify this. Even if similar extensions have been approved by the Council, I have no details of the contexts of those other sites, including in terms of their character and appearance or planning histories. In any case, the appeal has been determined on its own merits.

Overall, due to its scale, the proposed development would adversely affect the character and appearance of the host dwelling and the area generally. It would therefore conflict with Policy DE1 of the Local Plan. The policy seeks to ensure that development proposals are of a high standard of design, which amongst other matters, take account of existing built characteristics. It would also not comply with the aims of the Framework or the SPD, which together, amongst other matters, seek to ensure that developments are visually attractive and sympathetic to local character.

The proposal would conflict with the development plan and there are no material considerations which would outweigh this finding. For the reasons given above the appeal is dismissed.