Appeal 3323548

The appeal is dismissed.

The appeal is dismissed.

As set out above there are two appeals on this site. They differ only in the detail of the design of the proposed extensions. I have considered each proposal on its individual merits. However, to avoid duplication I have dealt with the two schemes together, except where otherwise indicated.

The main issue in both appeals is the effect of the proposals on the character and appearance of the appeal dwelling, the group of buildings of which it forms part and that of the local area, with reference to the Ladbroke Conservation Area (the CA). Appeal Decisions APP/K5600/D/23/3323555, APP/K5600/D/23/3323548

The appeal dwelling is a mid-terrace 5 storey house, including a lower ground floor, set behind a palisaded area enclosed by railings. At roof level the appeal dwelling does appear to maintain its original form of a butterfly roof with a central valley, which appears to reflect the predominant roof form of the properties in the terrace. As part of a terrace of similar characterful properties, with a substantially unaltered parapet roof line, the appeal dwelling makes a significant contribution to the local street scene.

The Council has recognised the importance of this part of Kensington and Chelsea as a heritage asset through designation of the CA . The Ladbroke Conservation Area Appraisal (2015) (the [name]) clarifies its significance as an area that is predominantly of made up of 19th Century terraces, with many terraces designed to follow the contours of the hill so that the roof parapets remained continuous and unbroken. With stucco predominating the types of housing built, which are highly significant and distinctive to the area. The communal gardens situated behind houses, including the appeal dwelling are a special feature of the area.

The CA appears to retain much of its original roof forms, and these make a positive contribution to the character and appearance of the conservation area, particularly where they provide a consistent roofline as a group. The CA Appraisal notes that the appeal dwelling, and the terrace of which it forms part, make a positive contribution to the significance of the CA and identifies the historic parapet concealing the butterfly roof forms as making a significant contribution to local character. Therefore, I find that the significance of this part of the CA, as it relates to this appeal, to be primarily related to the continuous roofline of its buildings as originally conceived.

In line with the duty imposed on me by section 72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990, I have given considerable importance and weight to the desirability of preserving or enhancing the character or appearance of the Conservation Area.

Appeals have been submitted for different proposals. The first (Appeal A) relates to the proposed construction of a slate hung mansard type roof extension of traditional design, with a shallow pitched roof and extensive timber framed sash windows to the front and rear, with setbacks of approximately 0.2 metres from the front and rear parapets. The proposed extension would provide 2 additional bedrooms and bathroom with shower. The second (Appeal B) relates to the proposed construction of a slate hung roof extension with a steeply pitched roof design, approximately 3.48 metres in height with a rooflight to the ridge. It would be set back approximately 1.93 metres from the front parapet, with rear dormer windows that would be set back approximately 0.2 metres from the rear parapet. It would provide a single additional room with a separate large bathroom.

The proposed mansard extension would be visible in immediate and longer views of the appeal dwelling and terrace from along the street. From my site visit, it was evident that, due to its height and scale and proximity to the parapets, the proposed mansard roof would result in the loss of the original parapet with hidden butterfly roof form. For these reasons it would also be Appeal Decisions APP/K5600/D/23/3323555, APP/K5600/D/23/3323548 unduly prominent in these street views, and views from the surrounding properties and the gardens to the rear of the appeal dwelling. This includes views from the communal garden for the terrace of which the appeal dwelling forms part.

Due to the extent and proportion of the timber sash widows proposed, the fenestration of the proposed mansard extension does not reflect the existing fenestration hierarchy of the appeal dwelling and would result in it appearing over scaled and incongruous. In combination with the overall scale and prominence of the proposed mansard extension, this would result in an unsympathetic addition to the appeal dwelling that would detract from its original appearance.

Furthermore, from these public and private viewing points, the proposed extension would also appear as a disruptive element in the otherwise harmonious roof form and profile of the terrace as a whole and would fail to preserve the character or appearance of the CA in this regard, thereby, failing to preserve its significance.

The proposed roof extension that is the subject of this appeal would replace the existing butterfly roof and retain the existing parapets . It would have a tall steeply pitched and tall roof but with a traditional balance between the proposed slate hung roof and timber sash glazing, reflective of the appeal dwelling’s existing fenestration hierarchy. It would have a greater setback from the front parapet than the extension proposed in Appeal A, which would result in it being less apparent in more immediate street views.

However, despite this slightly reduced footprint and more balanced fenestration, the extension proposed would be of a height and scale that would appear prominently in wider street views and the other views of the appeal property that I have identified, particularly from the rear. In these views, it would appear as an unduly prominent and incongruous addition to the appeal dwelling, detracting from its character and appearance. Further, it would also appear as a disruptive element in the otherwise harmonious roofscape and profile of the terrace as a whole, thereby, also failing to preserve the significance of the CA.

Both appeal proposals would replace the existing butterfly roof but would retain the existing parapets. Whilst a recent planning permission1, appears to indicate a replacement flat roof form, from my site visit, it is apparent that, although recent roof alterations with rooflights have been carried out, the appeal dwelling substantially retains its original butterfly roof form. However, the recent planning permission would also not result in a visual interruption of the existing parapet roof line from the surrounding public or private realm, including from nearby buildings.

The appellant has drawn my attention to planning permissions for roof level extensions and alterations to houses of similar scale to the appeal dwelling within the wider CA, however, these appear to be of some age. Of particular note is the mansard roof extension at [address], which interrupts the otherwise continuous roof line of the terrace, evidently detracting from its 1 Planning ref: PP/19/05867 Appeal Decisions APP/K5600/D/23/3323555, APP/K5600/D/23/3323548 character and appearance. Planning conservation practice and policy evolves and develops over time, and these would have been considered on their own merits at the time of the decision. I have done likewise in my consideration of the appeal proposals and have only afforded these older planning permissions limited weight in my considerations.

The appellant has also drawn my attention to a more recent planning permission2 for a roof extension to a purpose built detached block of flats at [address]. The scale and form of this building is, therefore, substantially different to the appeal dwelling. It does not form part of an historic terrace of houses and has an entirely different context to that of the appeal dwelling, where the significance of this part of the CA, as it relates to this appeal, is in the historic continuous roofline of buildings in the terrace. I have, therefore, only attached moderate weight to this permission in my considerations.

I find, therefore, that the proposed roof extensions would be harmful to the character and appearance of the host dwelling, the terrace of which it forms part, and would fail to preserve or enhance that of the CA. In the context of paragraph 199 of the National Planning Policy Framework (2023) (the Framework), the harm I have identified to the significance of the CA would be less than substantial. This would be contrary to policies CL1, CL2, CL3, CL6, CL8 and CL11 of The Royal Borough Kensington and Chelsea Local Plan (2019), which seek to ensure that roof level development is architecturally sympathetic to the age and character of the host building and group of buildings, reinforces their original integrity, does not harm the character and appearance of the existing building, respects the existing views, is of high architectural and urban design quality and preserves or enhances the appearance and character of conservation areas. For these reasons the developments proposed would also not accord with Policies D3 and HC1 of the London Plan (2021) and sections 12 and 16 of the Framework.

Whilst both extensions proposed in these appeals would have benefits, in that they would provide additional extra room or bedroom accommodation and bathroom facilities, which would enlarge the existing house for the benefit of existing and future occupiers, this is not a substantial public benefit. Planning decisions should, in general, be made in the wider public interest. In this context, the harm I have identified, including the less than substantial harm to the significant of the CA outweighs these benefits.

The appeals are dismissed.