Appeal 3335526

The appeal is allowed and planning permission is granted for alterations including erection of side dormer roof extension and rear dormer roof extension (with french doors and safety railings) at [site address] , London, SW18 5OP in accordance with the terms of the application, Ref 2023/3453, dated 14 September 2023, subject to the conditions set out in the schedule at the end of this decision.

The application form described the proposed development as “Alterations to front slope, Alterations to SVP and corresponding duct works, Erection of a Side and [name]”. The council changed this to the description used in the heading above, as did the appeal form. I have adopted it as it more clearly identifies the development proposed.

The officer’s report considers that the form, massing and style of the proposed side dormer roof extension would largely match the height and scale of existing side dormer roof extensions between Nos.47 and 55 and would be constructed of materials sympathetic to the special character and appearance of the host property and the [address] Conservation Area. Therefore, the main issue in this case is the effect of the proposed rear dormer roof extension on the special character and appearance of the property, the consistency of local spatial character, and the [address] Conservation Area.

The starting point is the legislation and planning policy. Section 72 of the Planning (Listed buildings and Conservation Areas) Act 1990 requires that special attention shall be paid to the desirability of preserving or enhancing the character or appearance of the Conservation Area. The parties are familiar with development plan policies, so that I will simply say that policies LP3 and LP5 of the Wandsworth Local Plan are the most relevant. Policy LP3 states that development proposals will be supported where they sustain, preserve and wherever possible, enhance the significance, appearance, character, function and setting of any heritage asset, whist policy LP5 states that planning applications for extensions and alterations to existing residential properties will be supported where the proposal respects and/or complements the form, setting, period and detailing of the host building, uses matching or complementary materials, and would be visually subservient to it.

[name] are consistent with the National planning Policy Framework (the Framework). Paragraph 205 of the Framework (December 2023) states that “When considering the impact of a proposed development on the significance of a designated heritage asset, great weight should be given to the asset’s conservation (and the more important the asset, the greater the weight should be), irrespective of whether any potential harm amounts to substantial harm, total loss or less than substantial harm to its significance”.

The appeal site is a two-storey, semi-detached dwellinghouse with a single-storey rear extension. The site is located on the west side of [address], with similar two-storey, semi-detached properties surrounding. The proposed rear dormer roof extension would have a hipped roof and would wrap around the angle of the hip, to join the proposed side dormer. It would be 4m in width, 4.25m in depth at the roof, 2.1m in height to the eaves and a maximum of 3.3m in height. It would be finished in hung clay tiles (with a red clay tiled roof) and would have French doors in the rear elevation and a single window adjacent to the French doors.

The totality of the appeal proposals would result in an improvement to the symmetry of the pair, Nos.51 and 53, because the proposed side dormer would balance with the existing side dormer on the neighbouring dwelling. From that point of view, the scheme would be an improvement in terms of the character and appearance of the conservation area. Furthermore, the proposed rear dormer, and its somewhat unsatisfactory breaking of the rear hip-line would only be glimpsed from the frontage, if scanning between the roofs of Nos.53 and 55. The other possible view from the public domain would be from either of the nearby side roads – [address] to the south and [address] to the north. However, I was able to observe that trees and tall shrubs on the boundaries of the gardens on both roads, effectively prevent this.

I agree with the council that, from the non-public rear of the property, a scheme that included a rear dormer consistent in scale and configuration with the existing dormer at the rear of No51 would be more visually satisfactory, but the degree of harm in the private views does not warrant refusal of planning permission.

I conclude that the proposed rear dormer would leave the character and appearance of the conservation area unchanged, thereby amounting to a preservation of that character or appearance. Furthermore, the local plan policies would be met in respect of the appearance of the development from public viewpoints. For these reasons the appeal will be allowed.

The statutory condition that provides a time limit on the start of development must be imposed. In addition, the council has suggested a number of conditions in the event that the appeal is upheld, which I will adopt. I have considered these in the light of Planning Practice Guidance. I consider that the conditions should be imposed for the following reasons: condition 2 is required for certainty and avoidance of doubt as to the development permitted; condition 3 is to ensure that the appearance of the development permitted integrates with the existing in a visually satisfactory manner; condition 4 is to ensure no loss of privacy to the neighbouring property; and condition 5 is in the interests of preserving the character and appearance of the conservation area.

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 approved plans: [name]: Proposed Block Plan B001, Proposed Ground Floor Plan P001, Proposed First Floor Plan P002, Proposed Second Floor Plan P003, Proposed Roof Plan P004, [name] P005, [name] P006, [name] P007, Proposed Section B P008 and Proposed Section B P009.

All external materials used in the construction of the development hereby approved shall match the type, texture, tone, colour, size and profile of those used on the existing building and shall be retained permanently.

Prior to occupation of the development the window in the side elevation at second floor level of the development shall be obscure-glazed and non-opening (unless the parts of the window which can be opened are more than 1.7 metres above the floor of the room in which the window is installed). The windows shall be so maintained and retained as such.

The rooflights hereby approved, shall be of a conservation area specification ie, in-line and flush with the roof pitch within which they would be located. The rooflights shall be so maintained and retained as such. End of Schedule