Appeal 6005356

The appeal is allowed and planning permission is granted for the erection of a ground floor rear extension and a mansard loft conversion to a terrace house at [site address] , Wandsworth, London [postcode] in accordance with the terms of the application, Reference 2025/3463 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: SP-00, SP-09, SP-10, SP-11, SP-12, SP-13, SP-14, SP 15, SP-16, SP-17, Planning Fire Safety Strategy, [name]

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

The rooflights hereby permitted shall be of a conservation type and shall be installed flush with the plane of the roof slope.

The roof area of the ground floor rear extension hereby permitted shall not be used as a balcony, roof garden or similar amenity area.

The main issue is the effect of the proposed development on the character and appearance of the host dwelling and the surrounding area, including whether it would preserve or enhance the character or appearance of the Park Town Conservation Area (CA).

The appeal property is a mid-terrace dwelling within a predominantly residential area. The dwelling forms part of a terrace characterised by a consistent architectural composition, including coherent facades, uniform eaves and ridge lines, and a regular chimney stack rhythm.

The appeal site is also located in the CA. The terms of Section 72 of the Planning (Listed Buildings and Conservation Areas) Act 1990 require me to pay special attention to the desirability of preserving or enhancing the character or appearance of conservation areas.

The Park Town Estate Conservation Area Appraisal and [name] (CAA) identify the CA as a planned Victorian estate characterised by a coherent street pattern, fine-grained urban form and a varied architectural composition. Its significance derives from this combination of consistent terrace forms and diversity of architectural expression, which together contribute to its architectural and historic interest. In this context, the appeal dwelling forms part of a largely uniform terrace and makes a positive, albeit unexceptional, contribution to the character and appearance of the CA.

The proposal would introduce a mansard roof to the rear roof slope, set above the eaves and below the ridge, incorporating dormer elements and a modest increase in the party wall height. The mansard would be partially contained behind the parapet, while the existing ridge, eaves lines and chimney stack would be maintained, ensuring the primary elements of the roofscape remain clearly legible and that the addition would read as a visually contained alteration within the overall roof form.

The rear roof slope is not visible from [address] or from the principal public areas in which the terrace is experienced. Public visibility is instead limited to oblique and relatively distant views from a short section of [address]. Whilst the Council considers that the development would be prominently visible from this location, my observations on site indicate that, due to the distance, angle of view, intervening built form and tree screening, such views would not afford a clear or sustained appreciation of the altered roof form. Instead, the perception of the roofscape in these views is dominated by the consistent eaves line and chimney stack rhythm. The proposal would retain these defining characteristics and sit within the established roof silhouette, preserving the terrace’s skyline.

While some limited views may be available from neighbouring properties, including those to the rear on [address], the tight urban grain, shallow garden depths and the markedly lower building heights of these dwellings, would significantly limit the mansard’s visibility and perceived presence.

Although the terrace roofscape is relatively consistent, it is not experienced in isolation. The wider CA includes a range of roof styles and subsequent alterations, such as mansard and dormer extensions on nearby terraces, some visible from the public realm, reflecting an established pattern of change. In this context, where the proposal is visible, it would not be read as incongruous but rather as a continuation of this pattern of adaptation.

The Wandsworth Local Plan Housing Supplementary Planning Document (2016) (the SPD) advises that in conservation areas, original building appearances should be preserved. In this case, the site-specific circumstances, including the limited visibility of the proposal and the retention of the roofscape’s defining architectural features, ensure that the overall roof profile and silhouette of the terrace would remain legible and continue to define its character. It would therefore preserve the appearance of the building in accordance with the guidance in the SPD.

The Council raises no objection to the proposed rooflights, subject to a suitably worded condition. Given the pitch of the front roof slope, these would have limited presence and would not be readily visible from the street scene, and I see no reason to disagree with that assessment.

Taking these factors together, the proposal would have a neutral effect on the significance of the CA, preserving its overall character and appearance. The alteration to the host dwelling would have limited visual impact and, where visible, would read as a proportionate response to its context, forming part of the area’s architectural evolution rather than representing a discernible impact upon its heritage value.

The Council has raised no concerns in respect of the ground floor rear extension. Based upon the evidence before me, and my observations on site, I concur with that assessment.

Overall, I conclude that the proposal would not harm the character or appearance of the host dwelling or the surrounding area. It would also preserve the character and appearance of the CA as a whole and there would be no harm to its significance as a designated heritage asset. As such, the proposal would accord with Policy HC1 of the London Plan (2021) and Policies LP1, LP3 and LP5 of the Wandsworth Local Plan 2023-2038 (2023), which amongst other things, seek to protect heritage assets and deliver design that protects the character of existing buildings. For the same reasons, the proposal accords with section 16 of the National Planning Policy Framework (2024) (the Framework) relating to conserving the historic environment.

The Council raises no concerns in respect of residential amenity, including in respect of daylight, sunlight, outlook or privacy. Based on the scale, position and design of the proposal, including the mansard, I am satisfied that it would not result in unacceptable harm to neighbouring living conditions.

I have considered the third-party objections that the granting of planning permission would set a precedent for other similar developments. However, each application and appeal must be determined on its individual merits, and a generalised concern of this nature does not justify withholding permission on these grounds in this case.

I have considered the conditions suggested by the Council against the tests of paragraph 57 of the Framework and advice in the Planning Practice Guidance. In addition to the statutory time limit condition, a condition specifying the relevant plans is necessary to provide certainty. Conditions, with wording amended where necessary in the interests of clarity and simplicity, relating to materials and design of the rooflights are also reasonable and necessary in the interests of safeguarding the character and appearance of the area. A condition, with wording amended for clarity, restricting the use of the roof area of the ground floor extension is necessary in the interests of protecting the living conditions of neighbouring occupiers.

For the reasons given above, having taken account of the development plan as a whole, along with all other relevant material considerations, the appeal should be allowed.