Appeal 3285702

The appeal is dismissed insofar as it relates to the mansard roof extension and lead covered dormers with timber framed sash windows. The appeal is allowed insofar as it relates to replacement railings and planning permission is granted for replacement of non-original railings to match the existing railings on the street at [site address] in accordance with the terms of application [name]/21/04471, dated 29 June 2021, and the plans submitted with it so far as relevant to that part of the development hereby permitted and subject to the following conditions:

The development hereby permitted shall begin not later than 3 years from the date of this decision.

The railings hereby permitted shall be erected in accordance with the following approved plans: 34 HP 05 and 34 HP 06.

The main issues are the effect of the proposed development on the character and appearance of the existing building and the Kensington Conservation Area (the CA).

No34 [address] is a 2-storey terraced dwelling sited at the junction of [address] with [address]. The building is set behind open lightwells about a basement level and bordered by railings to the back of the pavements. This part of the CA is primarily made up of modest mid-C19 terraced residential properties of 2 or [address] pattern.

The buildings have a high degree of consistency in their scaling and features. These include raised entrance doorways above a flight of steps. Ornate door and sash window surrounds feature at ground floor, with architraves to the upper floor openings. Detailed cornice bands below a parapet create a strong consistent linear edge to the continuous front rooflines on much of [address]. The buildings are finished in painted brickwork or stucco which, alongside the architectural detailing, provides a pleasant aspect to the houses and creates a strong sense of place with a high degree of consistency to the character of development in the locality.

The proposal would introduce a prominent mansard extension set behind the limited height parapets. The extension would incorporate two lead-covered dormers to the broader frontage facing [address], and a single dormer addressing [address]. The roof extension would adjoin a party wall upstand formed as part of a similar extension to the neighbouring [address]. Railings with a consistent appearance to original examples in the street would replace existing non-original railings.

The significant majority of the local buildings were constructed having a flat roof with no visible party upstand. [address], the introduction of the mansard roof form would interrupt the regular simple lines of the main terraces which contribute to the consistent character of this part of the CA. Although mansard roofs are a common form of extension found in the wider area, they are not characteristic or reflective of the basic form of the buildings found on [address] or the similar traversing streets. The introduction of the roof extension would draw focus in views along the road. This would detract from the consistent character of development along [address], which is identified as a positive contributor to the CA.

At my site visit I saw that some examples of similar extensions were present in the locality. [address], the proposal would be seen in conjunction with the mansard extension at No10. Although the proposal would screen views of the existing party wall with No10, this would be replaced with something of greater visual prominence. The combined run of rooftop development would create a heavier visual mass to draw the eye and further undermine otherwise consistently styled development along that frontage. Other examples of rooftop additions in the vicinity are very much in the minority and, in any case, the existence of development elsewhere does not represent an appropriate reason to find in favour of a proposal that would cause harm.

The appellant draws my attention to the taller corner buildings sited about the junction of [address] with [address]. These act as focal buildings central to the area of similar residential development. Those examples and another at the junction with [address], appear as buildings with consolidated and consistently styled elevations. They are therefore distinct from a proposal with contrasting design and finishing. Accordingly, I am not persuaded that those buildings justify a development of a distinctly different appearance.

Under the duty imposed under s 72(1) of the Town and Country Planning (Listed Buildings and Conservation Areas) Act 1990 I am required to pay special attention to the desirability of preserving or enhancing the character or appearance of the CA. For the reasons set out above, I conclude that the development would cause harm to the character and appearance of a building with consistent styling to surrounding residential properties. The extension would conflict with the characteristic development in the locality and detract from its consistency in appearance to adversely affect the character and appearance of the CA. The National Planning Policy Framework (the Framework) is clear at Paragraph 199 that ‘great weight should be given to the asset’s conservation’.

Although this harm would be no greater than less than substantial in the context of Paragraph 202 of the Framework, less than substantial harm does not equate to a less than substantial planning objection. I note the possible public benefit of the proposal to replace the existing railings with some to match the original design visible at other properties. This is not disputed by the Council. I also note that the construction of the proposals would support the economic recovery following the initial effects of the pandemic. However, whether taken individually or together, I find these benefits do not outweigh the significant harm to the CA arising from the roof extension.

For the above reasons, I find the proposed roof extension would cause significant harm to the character and appearance of the building and the CA. It would conflict with Policies CL1, CL2, CL3, CL8 and CL11 of the Royal Borough of Kensington and Chelsea Local Plan [2019] as they require development to respect and contribute positively to the character and appearance of the built environment, including preserving or enhancing Conservation Areas.

In support of the appeal, the appellant refers me to recent changes to the Town and Country Planning (General Permitted Development) (England) Order 2015 which enables some upwards extensions to facilitate new or extended housing. However, these provisions do not apply within Conservation Areas. I acknowledge that opportunities provided by upwards extensions can assist in meeting housing requirements, particularly in constrained areas. However, this is not without due regard to their effects on the character and appearance of their locations.

I also acknowledge that the proposal would create additional space for a growing family and avoid a requirement to move to a bigger house. These are not benefits necessarily dependent on the success of this planning appeal and, in any case, would not outweigh the harm I have identified.

I have noted other objections from third parties to the proposal. However, in the light of my findings on the main issues of the appeal, my decision does not turn on those matters.

For the reasons given above, I conclude that the proposed mansard roof extension would harm the character and appearance of the building and CA. It would conflict with the development plan taken as a whole. There are no material considerations that indicate the decision should be made other than in accordance with the development plan. Therefore, for the reasons given, I conclude that the appeal should be dismissed in relation to the roof extension.

The appeal should be allowed insofar as it relates to the replacement of the existing railings with railings to match the original style of railings found elsewhere in the street.