Appeal 3326351

The appeal is dismissed.

The main issue if the effect of the proposal on the character and appearance of the appeal dwelling and that of the Pimlico Conservation Area (PCA), and the setting of the [address] Conservation Area (PACA).

The appeal dwelling is a mid-19th Century three storey end of terrace house located on the Corner of Lupus street and [address]. It forms part of a group of three houses of similar design scale and age, with a simply designed circa 1950’s three storey block of flats adjoining.

Through the designation of the PCA, the Council has recognised the local area within which the appeal dwelling sits as a heritage asset. The Pimlico Conservation Area Audit (the [name]) clarifies its significance as an area with a highly disciplined and formal street layout primarily made up of substantial houses, many of architectural and townscape significance, including the appeal dwelling. Further, the appeal dwelling sits on the boundary of the PCA with the PACA and forms part of its setting.

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.

The PCA audit identifies the appeal dwelling as an unlisted building of merit. The significance of which rests in its mainly unaltered appearance and prominence, forming a key feature in the context of the CA. This results in it being a Non-Designated Heritage Asset (NDHA), as defined by the provision of the Planning Practice Guidance. I have considered the effect of the proposal in line with paragraph 203 of the National Planning Policy Framework (2023) (the Framework) accordingly.

Whist the Council’s decision notice sets out that the reason for refusal is the effect of the roof extension and associated terrace, the Council has however raised concerns with regard to other aspects of the proposal, where further design clarification would be required. I am satisfied that a suitable condition applied to an approval would be able to effectively manage these other design matters. Accordingly, I will only address the reason given for refusal.

The proposed mansard roof extension would occupy the majority of the existing roof area behind an existing parapet but would be set back from the corner edge of the building that is adjacent to the junction of [address] with [address], to leave a proposed area for a roof terrace. The roof of the appeal dwelling, along with its neighbours in the terrace, is defined by this parapet edge and is noted in the [name] as being largely unaltered at roof level.

The appellant has drawn my attention to the substantial number of mansard extensions within the local area and the wider PCA. However, the PCA audit is clear about the harm that results from the majority of these to the original historic character and appearance of the houses and streets in the area. Heritage planning and design has evolved over time, and it would appear that many of the existing mansards in the area are of some age. The PCA Audit further identifies buildings where roof level extensions would, not normally be acceptable, including the appeal dwelling and the other houses in the terrace. I have, therefore, afforded the existence of the many older mansard extensions in the area only limited weight in my considerations.

I acknowledge that the appellant has sought to develop a design for a roof extension with a limited effect on the profile of the existing dwelling and its neighbours. However, illustrative material provided by the appellant demonstrates that the proposed roof extension would be visible from across the street from where it would detract from the existing unaltered appearance of the appeal dwelling and terrace. As such, the proposed roof extension and associated terrace would appear as an unduly prominent and incongruous addition to the appeal dwelling and would, therefore, fail to reflect its existing character and appearance and significance as a NDHA.

From my site visit it is apparent that the appeal dwelling, and the group of houses of which it forms part, are prominently located on the edge of the PCA. The street layout and corner location of the appeal dwelling results in there being extensive views of it, and the group of properties of which it forms part, from the public realm. Within these views the proposed extension would appear as a significant change to the design of the appeal dwelling and group of terraced houses and would appear as unduly prominent within the context of the local roofscape and townscape. This includes views from within and towards the PCA. As such, the proposed extension and installations associated with the proposed roof terrace would fail to preserve or enhance the character or appearance of the PCA.

Further, the harm caused by the 1950’s block of flats to the cohesive nature of the small group of terraced buildings of which the appeal dwelling forms part, would only be further added to by the proposal and does not provide a justification for this further harm.

Additionally, the proposal would be visible in the foreground and background of wider views of the PACA, where it would appear as a significant alteration and addition to the existing unaltered historic houses in the terrace, which due to their prominent corner location form an important part of the setting of the PACA. As such the proposal would appear as an unduly prominent and incongruous element within the setting of the PACA.

For these reasons, I find that the proposal would be harmful to the character and appearance of the appeal property and its significance as a NDHA, the significance of the PCA and to the setting of the PACA. This would not accord with the [name], Policies PIM3 and PM4 of the Pimlico Neighbourhood Plan (2022), Policies 38, 39 and 40 of the City Plan 2019-2040 (2021), policy HC1 of the London Plan (2021) and Section 16 of the Framework, which collectively seek to ensure that development is of high quality design, having due regard to the importance of preserving or enhancing heritage assets.

I find that the harm to the appeal dwelling as a NDHA would be substantial, although the harm to the PCA and setting of the PACA would be less than substantial. In accordance with the Framework, great weight should be given to the conservation of these heritage assets. The proposed roof extension and roof terrace, whilst increasing the size of the appeal dwelling and improving amenity of occupiers would not provide any further bedrooms and would be of primarily private benefit. I must give considerable importance and weight to the effect on the significance of the PCA, the setting of the PACA and, in addition, significant weight to the effects on the character and appearance of the appeal property as an NDHA. I consider that these benefits do not outweigh the harm I have identified.

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