Appeal 3338260

The appeal is allowed and planning permission is granted for erection of a rear mansard extension on top of the existing outrigger following the removal of an existing roof terrace at second floor level to the rear elevation and fenestration alterations to the lower ground and second floors in accordance with the terms of the application Ref 2023/02339/FUL, dated 31 August 2023, 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 the following approved plans: Location plan and 22075-XX-A-105-Rev03.

The development hereby approved shall be carried out and completed in accordance with the materials (including colour and finish) specified on the application form and on the drawings hereby approved. The development shall be permanently retained in accordance with the approved details. Any works of making good to existing elevations shall be carried out in materials to match the elevation to which the works relate.

Prior to the occupation of the second-floor rear extension hereby permitted, the new flank window at second floor level in the west elevation as shown on approved drawing No 22075-XX-A-105-Rev03 shall be fitted with obscure glass to a minimum level of obscurity equivalent to [name] 3, and shall be non-opening and fixed shut up to a height of 1.7m above the finished floor level of the room in which the window is situated. The window shall thereafter be permanently retained as approved.

The main issues are: i) Whether the proposal would preserve or enhance the character or appearance of the Bradmore Conservation Area; and ii) The effect on living conditions at the neighbouring properties 9 and [address], in terms of impacts on light, outlook and privacy.

[site address] is a handsome and well detailed mid-terrace house, typical of this part of the conservation area. Although not listed or locally listed, it’s frontage in particular adds to local character and the street scene. It is 3 storeys, including a lower ground floor, plus rooms in the roof. Like many of the other houses in the immediate vicinity, it has a full height flat roofed outrigger to the rear, taking up about half the width of the house. The main part of the proposal, to which the Council objects, is a mansard style extension in place of an existing roof terrace with glass balustrade, on top of the outrigger. The Council raises no concerns about the other minor window alteration proposed.

The high level flat roofs of the outriggers here, though typical of the area, are not quality features. The existing glass balustrade at [site address] is a minor installation, but not typical of the area. Many of the other houses nearby have high level extensions and alterations, including some mansard roof style extensions over outriggers. The proposal for No 10, though bulkier than some of the other existing extensions, would fit in well within this varied roofscape, improving the quality of the built development at No 10.

The Council considers that there is a predominantly unified rear building line at [address], but there are other high level extensions. The proposed design, scale and materials would fit in with the building and the terrace. Though the proposal would be seen from adjacent roads, though gaps between buildings, and from neighbouring properties it would not be a prominent or particularly distinctive feature in those views. The more important front elevation of the building and views from [address] would be unaffected.

I conclude that the proposal would preserve the character and appearance of the conservation area. It accords in this respect with policy HC1 of The London Plan, policies DC1, DC4 and DC8 of the Hammersmith and Fulham Local Plan 2018 (HFLP), the Council’s Planning Guidance Supplementary Planning Document (SPD) and the National Planning Policy Framework, which taken together aim to create a high quality urban environment that respects and enhances its townscape context and heritage assets. In coming to this conclusion, I give special attention to the desirability of preserving or enhancing the character or appearance of the conservation area as required by Section 72 of the Planning (Listed Buildings and Conservation Areas) Act 1990.

[name] HS7 uses a 45 degree guideline to assess the impact of extensions on neighbours’ outlook. It looks for unobstructed views at 45 degree angles in both the horizontal and vertical planes from neighbouring windows serving habitable rooms.

No 9 next door to the east has a matching rear outrigger so that its main rear windows would not be affected by the proposed extension. There is a second floor level window set further back, close to the boundary with No 10, but this is high enough that it would retain a wide, open aspect and good natural light including views of the sky over the top of the extension. In terms of the HS7 guidelines, the horizontal 45 degree line would be breached, but not the vertical line. The overall impact would not be significant. Another second floor window set further away would be even less affected. No new windows would face No 9 so that occupiers’ privacy would not be significantly affected either.

The closest windows at No 11 to the west are set well away from the proposal so that the horizontal 45 degree line would not be breached. Although the proposal would breach the vertical 45 degree line for ground floor and lower ground floor windows at No 11, the actual difference between the existing situation and the new situation would too marginal to cause material harm to outlook or light.

The proposal would have a second floor level side window facing towards No 11, which would be a secondary window to the proposed new room. That window would potentially provide more shielded views than existing views from the open terrace, but could be obscure glazed to protect neighbours’ privacy.

I conclude that, subject to a standard condition requiring obscure glazing of the new side window, the proposal would not harm living conditions at either 9 or [address]. It accords in this respect with HFLP policies DC4 and HO11 and the SPD, which aim to ensure that extensions are designed with good neighbourliness in mind, respecting the amenity of neighbouring properties.

I have considered all other matters raised, including the comments of local objectors. I note that a front garden bike shed indicated on the plans is not part of this proposal. Any need for access to a neighbouring property for building works is controlled under other legislation.

I impose a condition specifying the relevant plans to provide certainty. A condition requiring use of the materials specified in the application is needed to protect local character. A condition requiring the obscure glazing of a new, high level side facing window is also necessary to protect the privacy of occupiers of [address] next door, as set out above. The Council suggests a further condition requiring compliance with the submitted Flood Risk Assessment, but that document makes no specific recommendations for this high level extension, so this condition is not needed.

I find that the proposal accords with the development plan for the area. For the reasons set out above, I conclude that the appeal should succeed.