Appeal 6005168

The appeal is allowed and planning permission is granted for erection of a part single/part double-storey rear extension, a double-storey side extension, loft conversion with a rear dormer extension, alteration to fenestration and installation of rooflights, following demolition of the existing side extension and garage at [site address] in accordance with the terms of the application, Ref 25/02812/HOUSE, subject to the following conditions:

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

The development hereby permitted shall be carried out in accordance with drawings labelled “Location Plan” ([name]-14378388v1), “Proposed Block Plan”, “[name]” ([name] 03, [name]), “[name]” ([name] 04, [name]), and “Existing and [name]” ([name] 05, [name]).

The external materials of the extension hereby permitted shall match those used in the existing dwelling.

Notwithstanding the description of development set out in the banner heading, which is taken from the application form, it is clear from the plans and accompanying details that the proposed development also comprises the installation of rooflights and elevational alterations. The Council dealt with the proposal on this basis and so shall I.

At my site visit, I observed that construction was underway. For clarity, my assessment is based on the plans before me, rather than what had been constructed to date. Any works carried out not in accordance with those plans would be a matter between the Council and the appellant.

The main issue is the effect of the proposed extension on the character and appearance of the host building and the surrounding area.

The appeal property lies within a section of suburban residential street characterised predominantly by two-storey semi-detached dwellings of broadly similar design. This section of the street exhibits a regular plot rhythm, consistent building lines, and generous front and rear gardens. Many of the semi-detached dwellings have side garages or extensions built up to the shared boundaries, and there is no established pattern of gaps between properties at ground-floor level. The properties in this part of the street also do not share a uniform roof form. Notably, the neighbouring property at No. [address] has a gable-end pitched roof, which appears to have been formed from the conversion of a hipped roof previously shared with the adjoining half of the semi-detached pair.

The Council’s Residential Extensions Supplementary Planning Document (2009) (the SPD) expects two-storey side extensions not to dominate the original dwelling. This is to be achieved by reducing their bulk, setting them back from the principal front elevation, and incorporating a lower roof. The SPD advises that side extensions should normally be set back at least 1m from the adjoining property to maintain the pattern of gaps in the street scene.

The proposed two-storey side extension would be visible from the street and would remove the first-floor gap above the existing garage. However, there are already single-storey garages at the appeal property and the adjoining No 38, leaving no gap at ground level. In addition, the first-floor element would be set back from the principal front building line by approximately 2m. It would also have a flat roof, with an eaves height aligned with that of the host building. Although the proposed parapet wall would marginally project above the eaves, the flat roof form would nonetheless reduce the overall height of the extension. In these circumstances, the proposed extension would not appear incongruous or out of keeping with either the host building or the wider street scene. Despite the absence of a 1-metre gap between the extension and the adjoining property, it would read as a subordinate addition, achieved through the setback from the front building line and the flat-roof design. As such, the two-storey side extension would generally accord with the overall design objectives of the SPD.

The proposal would also introduce a gable-end pitched roof without increasing either the ridge or eaves heights. Given the presence of similar roof form on neighbouring properties, including No 38, the proposed gable-end pitched roof would be acceptable, and would not detract from the established roofscape. It would therefore comply with the expectations of the SPD.

The proposed rear dormer would occupy the majority of the rear roof slope with limited set-ins from the sides and below the ridge. Nonetheless, it would retain the existing eaves and ridge and would remain visually subordinate to the roof as a whole. It would therefore generally accord with the SPD’s aim of maintaining visual appearance of the roof line and not detracting from the characteristic roof profile of the street. Given the separation distances involved, together with the presence of mature trees and vegetation along shared boundaries, the rear dormer would not be visually prominent when viewed from neighbouring rear gardens.

Overall, I conclude that the proposed extension would respect the character and appearance of the host building and the surrounding area. It would therefore comply with Policy SP1 of the Council’s Local Development Framework Core Strategy (2011) and Policy EN1 of the Allocations and Development Management Plan (2015), which, in summary, seek high‐quality design that respects the character of existing buildings and the local area.

Although this matter is not disputed between the Council and the appellant, concerns have been raised by interested parties regarding the proposal’s impact on neighbouring occupiers in terms of daylight and sunlight. Swanley Town Council has also requested that a 45-degree light test be undertaken.

From my site observations, [address] benefits from a ground-floor rear extension that projects further than the appeal proposal, and no harmful impact on that property would therefore be expected. [name] 38, its side window and nearest first-floor window to the appeal property are obscurely glazed. While the Council has noted that the proposal would not satisfy the 45-degree test in relation to the closest ground-floor window, it has also confirmed that this window serves a non-habitable room. In addition, No 38 sits at a higher ground level than the appeal site. For these reasons, and having regard to the Council’s assessment, I am satisfied that the proposal would not result in a material loss of daylight or sunlight to neighbouring occupiers.

The Council also raises no objection in respect of parking provision, or the living conditions of neighbouring occupiers in relation to outlook or privacy, with particular reference to the neighbouring occupiers of No 38. On the evidence before me, I see no basis to reach a different conclusion on these aspects.

I have also had regard to the concerns raised by interested parties regarding noise and disturbance. However, given the modest increase in the number of potential future occupants at the appeal property as a result of the proposed extension, and that it would remain in use as a single-family dwelling, any associated increase in noise and disturbance would be limited.

In imposing conditions, I have had regard to the tests within the National Planning Policy Framework, the Planning Practice Guidance, and relevant statute.

Conditions specifying the time for commencement and requiring compliance with the approved plans are necessary for reasons of certainty.

A further condition requiring external materials to match the existing has been imposed is also necessary to ensure that the proposed development integrates satisfactorily with the host building and the surrounding area.

For the reasons given above, the proposal accords with the development plan when read as a whole. Material considerations do not indicate a decision should be taken other than in accordance with the development plan. I therefore conclude that the appeal should be allowed.