Appeal 6003574

The appeal is allowed and planning permission is granted for Retention of basement with single storey extension at ground floor level (3.5m deep), with roof terrace (3m deep) with alterations to add glazed balustrade, new timber staircase, new windows at basement level and obscure glazed screen on one side at [site address] , Finchley, Barnet, London [postcode] in accordance with the terms of the application, Ref 25/4103/HSE, and the plans submitted with it, 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: Site Location Plan; [name] ([name] and Ground Floor Plan) 0110 (02)_110; [name] ([name] &[name]); 0110 (02)_210 [name] ([name] and D); 0110 (02)_310 Proposed Section Proposal A.

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.

The use of the basement extension hereby permitted shall at all times be ancillary to, and occupied in conjunction with, the main building and shall not at any time be occupied as a separate unit or dwelling.

The roof of the ground floor extension hereby permitted shall only be used in connection with the repair and maintenance of the building and shall at no time be converted to or used as a balcony, roof garden or similar amenity or sitting out area. Appeal Decision: 6003574

The privacy screens on the approved plans shall be installed before the use of the terrace is commenced and retained as such thereafter.

The basement, single storey ground floor extension and roof terrace have been completed. I am therefore considering this appeal partly retrospectively.

I note that the Council’s Officer Report concluded that the ground floor extension would not result in harm to the character or appearance of the existing dwelling or surrounding area or neighbouring amenity. I have no reason to disagree with the opinion of the Council in this matter. Taking this into account, the only outstanding matter in dispute is with regards to the basement, roof terrace and the proposed alterations to the balustrade, screen and staircase.

The main issues are the effect of the development upon: • the character and appearance of the host building and the surrounding area; and, • the living conditions of occupiers of [address], with particular regard to outlook.

The appeal relates to a semi-detached house which backs onto [name]. The back gardens of houses on the appeal site side of Essex Park slope downwards towards the railway line to their rear. From my observations on site, and photographs provided by the appellant, it appears that many rear gardens are on [address] with steps down to the main garden below. Also, that several properties close to the appeal site have basements which are partially, or in some cases fully, visible from within their rear gardens. The design of rear extensions and basements nearby vary and lack consistency but, nonetheless, they are prevalent and form part of the character of the area around the appeal site.

The Council is concerned that the basement, terrace and steps down to the garden harm the appearance of the house and wider area because the depth and height of the basement and terrace are disproportionate, relative to the existing house and garden and the rear building lines of other houses, and the appearance of the screening around it is unsympathetic. The Council do not consider that the proposed alterations would adequately reduce the harm.

The basement is not visible from outside the appellant’s garden because of the boundary fence that surrounds it. Within the garden the basement is only partially visible because its floor level and door entrance are below the main garden ground level and are accessed via a stairwell. The roof terrace above it corresponds with the height of garden terraces on the neighbouring houses and therefore neither structure appear overly dominant. However, the balustrade and side screens around the terrace are comprised of white plastic panels which appear obtrusive Appeal Decision: 6003574 and bulky compared to metal railings or glass panels which are more commonly used and are present on properties near to the appeal site.

The fall in ground levels towards the rear of the garden enable views of the plastic panels over the top of the rear wooden fence. However, the only area of public realm from which they are visible is the station platform and the bridge crossing the railway line, to the rear of the site. Mature trees between the rear garden fence and the mesh fence that runs behind the station platform prevent views of the appeal site for much of the year. Although there were glimpses of the station during my visit, because the trees were not yet in leaf, the terrace is seen in the context of the neighbouring house, No 55, which has a rear extension and canopied terrace at a similar depth as the appeal development, and the rear of other properties which I have noted vary substantially in terms of the size and design of their rear extensions and the extent of their garden terraces.

The proposal includes replacing the concrete steps at the side of the terrace down to the garden with a more centrally positioned wooden open riser staircase and the plastic clad balustrades and screens with opaque glazed panels. Together they would have a less bulky more sympathetic appearance in keeping with those at the back of houses nearby.

Therefore, whilst the development does not fully align with the guidance in the Residential Design Guide Supplementary Planning Document (2016) (RDG), in terms of recommended depths and widths of basements and window alignment, it would accord with the SPD principles, in that it would not harm the established character of the appeal property or the surrounding area. Furthermore, I note that the Council has approved a scheme at the appeal site which would reduce the depth of the basement and terrace by 1.5m but would also substantially exceed the suggested depth and the width for basements set out in the SPD.

Overall, I conclude on this main issue that the proposed development would not conflict with Policy D3 of the London Plan (2021) (LP); the National Planning Policy Framework (2024) (the Framework), Policy CDH01 and CDH05 of the Barnet Local Plan (2025) (BLP), the [name] and Construction Supplementary Planning Document (2016) (SDC) and the design principles in the RDG which require extensions to be subordinate to the existing building and respond to local character.

No 51 adjoins the appeal property and has similar site levels. A garden patio projects from the rear of the house with steps down to the lower garden level. The floor level and depth of the ground floor extension on the appeal property is similar to that of No 51’s patio. The extension flank wall extends along the shared boundary, and the terrace above the basement projects a further 3m beyond the rear wall of the extension and the end of the neighbour’s patio. The white plastic panels along the side of the terrace prevents overlooking between the properties. The Council consider that the extension flank wall on its own does not harm the outlook from No 51 but in combination with the basement roof terrace and the proposed replacement privacy screen the development would appear overbearing from No 51’s windows and garden.

The existing privacy screen is lower than the flat roofed extension but significantly higher than the wooden boundary fence. The proposed replacement screen would Appeal Decision: 6003574 be set in 0.8m from the edge of the terrace and the extension wall. It would be a similar height to the existing screen but made of obscured glazed glass rather than plastic panels. Seen from the neighbour’s patio doors and garden, the set in would provide a visual break along the boundary and the glass would have a less solid appearance than the existing screen which together would lessen the visual impact of the development. Furthermore, the patio doors and other windows on the rear of No 51 are set in from the side of the house so the privacy screen would be peripheral to any views from them.

From the neighbour’s garden below the patio the screens would also appear peripheral, albeit substantially higher than the fence, but would nevertheless not appear too overbearing because of their distance from the boundary and lighter appearance. In the context of the varied levels and existing rear extensions elsewhere along Essex Park, any effects on outlook would not be significantly different than for other residents nearby and I note that the occupiers of No 51 have not objected to the proposal.

Overall, I conclude on this main issue that the proposed development does not conflict with Policy D3 of the LP, the Framework, Policies CDH01 and CDH05 of the BLP, the SDC and the RDG which require development to maintain an acceptable level of outlook and ensure that extensions are not overbearing.

For the reasons given above, I conclude that the appeal should be allowed.

I have had regard to the conditions provided in the Council’s Officer Report. The standard time limit condition and a plans condition are necessary to provide certainty. A condition concerning materials is necessary to ensure a satisfactory appearance. Conditions preventing the ground floor extension roof being used as a terrace and requiring the privacy screen to be completed before the basement roof terrace is brought into use are necessary to protect the neighbour’s privacy, although I am satisfied that the proposed screen and balustrade is acceptable, and no further details relating to its design are required. A condition preventing the basement being used as a separate unit of accommodation is necessary to protect the living conditions of occupiers of the proposed development.