Appeal 3305113

The appeal is allowed and planning permission is granted for ‘single storey rear extension, fenestration changes with new front door, roof extension involving rear dormer window, installation of external insulation to the existing walls and new cycle storage to front and rear patio’ at [site address] , Cricklewood, London [postcode] in accordance with the terms of the application Ref 22/1580/HSE dated 24 March 2022 subject to the following conditions:

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 following approved plans: CW-0239-001 Rev 01, CW-0239-010 Rev 01, CW-0239-100 Rev 01, CW-0239-110 Rev 01, CW-0239-200 Rev 01 and CW-0239-210 Rev 01.

No development above ground level shall take place until details of the materials, finishes and colours to be used in the construction of the external surfaces of the development hereby permitted have been submitted to and approved in writing by the Local Planning Authority. The development shall be carried out in accordance with the approved details.

The development description in the banner heading above is taken from the planning application form. However, the description used by the Council on the decision notice more accurately sets out the development proposed. As this revised description has also been adopted by the appellant on the appeal form, I have therefore used it in my formal decision.

The main issue is the effect of the proposal on the character and appearance of the host dwelling and area.

The appeal relates to a mid-terrace dwelling on [address] close to the junction with [address]. Closest to the site, these streets are predominantly characterised by terraced dwellings of a few similar original designs which sit on strong building lines. This provides for an overall sense of coherence to the street scenes despite a variety of external finishes to the buildings. To the rear though, there is more diversity in the form, scale and appearance of many of the individual buildings as a result of alterations including dormers and rear extensions of mixed design.

The Council has not raised concerns in relation to the proposed external insulation, changes to fenestration, rear patio or cycle store. Given the modest scale and visual impact of these alterations and the range of external finishes nearby, I am also satisfied that these elements of the proposal would not be detrimental to the character or appearance of the host building or area.

The proposed dormer would occupy nearly the full height, width and depth of the rear roofslope contrary to guidance within the Council’s Residential Design Guidance Supplementary Planning Document 2016 (‘the SPD’) that dormers should normally be subordinate features of the roof. However, the Council acknowledges that a dormer of this scale would be within permitted development limits, and I saw dormers of similar scale to many of the nearby buildings, including to the neighbour at [address]. Its size would not therefore stand out.

Most of the dormers nearby are clad in tile hanging, but there is notable diversity in their colour and shading which in many cases does not match the host or adjoining roofslopes. Differing proportions and arrangements of glazing add further variety to the appearance of the dormers, including an example at [address] which is nearly fully glazed to the rear. In addition, I saw that solar panels and rooflights have modified the appearance of some other tiled roofslopes. While the red standing seam zinc finish to the proposed dormer would not match the appeal or other nearby buildings, I find in the context of this diversity that it would not be incongruous nor unduly conspicuous. Instead, I consider that it would be a sympathetic, contemporary addition to the area.

The single-storey rear extension would be stepped, with a deeper section closest to No 100 of around 4m. This would exceed the depth of 3m that the SPD sets out will normally be considered acceptable for single-storey rear extensions to terraced properties. However, it would be of lesser depth than extensions to No 100 and to [address], and would not be out of keeping with other extensions nearby which vary in depth.

The roof of the extension would have a dual pitched design. I acknowledge that this would be unusual, and would not match the existing dwelling as generally sought by the SPD. Even so, the highest parts would be set below the first-floor windows, and the eaves and central valley would be much lower. The overall bulk and mass of the extension would also be broken up by the stepped design, and I am satisfied that the extension would be suitably subordinate relative to the host building so as not to dominate or overwhelm it. A rear garden of reasonable depth would also be retained to the rear.

Furthermore, while the majority of other rear extensions nearby may have flat roofs, there is little consistency in their height, and I saw that there were also examples of sloping roofs of different designs as well as projecting roof lanterns. As a consequence, the roofscape of the extensions in the vicinity of the site is far from uniform, and I find having regard to this variety that the design of the roof would not be striking or discordant, and the extension would not stand out.

Moreover, the siting of the dormer and single-storey extension to the rear of the terrace mean that neither would be readily apparent from surrounding street scenes, limiting their visual impact. There would be views from some neighbouring properties and gardens, but I consider for the reasons above that even when taken together, the rear extension and dormer would not be unduly prominent and would not unacceptably disrupt or detract from the established character or appearance of either the appeal dwelling or the area.

Although the development would not fully accord with the guidance in the SPD, I therefore conclude that the proposal would not cause unacceptable harm to the character or appearance of the host dwelling or area. Accordingly, I find no conflict with Policies CS1 or CS5 of Barnet’s Local Plan ([name]) Development Plan Document 2012, Policy DM01 of Barnet’s Local Plan (Development Management Policies) Development Plan Document 2012, or Policy D3 of the London Plan 2021. Amongst other things, these policies broadly seek high quality design that respects and responds to local context and distinctiveness and that makes a positive contribution to the borough, including through respect for the appearance, scale and mass of surrounding buildings and through the use of attractive, robust materials. A departure from the detailed guidance within the SPD is therefore justified in this case.

In addition to the standard time limit, I have imposed a condition specifying the approved plans for the avoidance of doubt and in the interest of certainty. The Council suggested a condition to require materials to match the existing building, but this is not what is proposed, and I have instead imposed a condition to require further details of the external materials, finishes and colours. I consider that this would be necessary to ensure a satisfactory appearance in the interests of the character and appearance of the dwelling and area.

For the reasons given above, I find that the proposal would accord with the development plan when it is read as a whole, and material considerations do not indicate that a decision contrary to the development plan should be reached. I therefore conclude that the appeal should be allowed.