Appeal 3290269

The appeal is dismissed.

The main issues are the impact of the proposal upon the host dwelling as a locally listed building and the character and appearance of the conservation area.

The appeal site is a two-storey detached residential property which stands within the [address] Conservation Area (CA). The property is a Locally Listed Building and is within the Harrow on the Hill Area of Special Character. I find the appeal site to make a positive contribution to the CA as is also acknowledged by the appellant. Whilst part of the consideration, within this appeal, is impact upon the designated heritage asset (the CA), the appeal site is a locally listed building. In that regard the effect of an application on the significance of a non-designated heritage asset should be taken into account in determining the application in accordance with paragraph 203 of the National Planning Policy Framework 2021 (the Framework).

The main house has a two storey extension to the north followed by a single storey “L shaped ‘wing’” with extensive glazing facing the forecourt/parking area of the property and a glazed lantern at the eastern end of the roof. These are existing pre-1947 extensions which are discrete, subservient and in-keeping with the Victorian character of the original building. The site has relatively extensive planning history which is well summarised within the submissions before me but despite this each case must be considered on its own merits.

The CA appraisal describes [site address] as a quiet lane with an enclosed and secluded feel with a sense of enclosure as buildings are densely packed close to the pavement. The buildings are described as having a grand yet unobtrusive design often with classical detail. From the plans before me I find that the host dwelling has a mostly symmetrical and classic form which is maintained, as the dominant feature, due the low level of the existing “L shape” extension. The proposal seeks to extend, at first-floor level, above the existing outbuildings.

At the time of my site visit I noted that the boundary wall to the garden and the solid entrance gates along the narrow lane mean that only the main upper part of the house is visible from the public realm. The existing “L shaped” extension, over which the extension is partly proposed, is itself therefore currently limited in views beyond the appeal site boundary in its current form. I find this is well demonstrated within the aerial view (figure 3) within the original heritage, design and access statement.

As a result of my site visit I find that the proposed extension would be seen above the boundary wall when approaching from the north along [site address] and from much of the lane adjoining the property despite the vegetation along the western boundary with [site address] . It is, I find, the scale, bulk and massing which presents as prominent. Whilst the proposal may not exceed the existing eave height of the original host dwelling its width would be comparable, at two stories, to the host dwelling which I find would not present as an ancillary wing. I note the proposal would retain previous extensions but the proposed first-floor extension I find would be visually prominent and would be seen to be at odds with and dominate the appearance of the main house regardless of materials utilised or the setback which is noted within the proposed sections. Additionally due to its visual impact and presence above the boundary wall this would I find, as noted by the conservation officer and previous Inspector, still result in lighting being visible at night within the CA adding further to the visual impact found.

The proposal would not preserve the special interest of the locally listed building as it would result in scale and form which would not complement the architectural form of the host house. I do not find that removal of the existing full-length glazed windows would be of such a benefit to the host dwelling to outweigh the harm found as a result of the first-floor extension. The proposal would detract from the setting of the house, remove details of earlier extensions as well as obscure the relationship between the existing modest Victorian extensions and the main house. I do not find that the proposal would be recessive or subordinate. It therefore follows, in this case, that the proposal would be out of notably out of keeping outside of the appeal site itself and I find that this would harm both the character and the appearance of the CA, not preserve or enhance it as required.

I note that within the planning history of the site permission was granted in 2008 under ref. P/1228/08DFU for a two storey extension with a more traditional form set down below the eaves of the main roof. The proposal before me would have a hipped roof which would be taller (ridge height of the extension to the existing eave height), and bulkier, than that which was previously approved in 2008. This is demonstrated in the approved front elevations which have been included for reference within the original heritage, design and access statement (June 2021) as well as the appellant’s appeal statement. [name] note the appellant contends the 2008 permission could be implemented and indeed I do give this weight but I find that the previous permission was overall more sympathetic and preferable to the scheme which is before me, due to the width and height, which was more modest in overall scale by comparison to that before me.

The proposal would be contrary to [name] 2012 Policy CS1 which requires all development to respond positively to the local and historic context in terms of design and respect their host building. The proposal would be contrary to Harrow Development Management Policies Local Plan 2013 (LP) Policy DM1 which confirms that proposals that fail to achieve a high standard of design and layout, or which are detrimental to local character and appearance, will be resisted and LP Policy DM7 which requires that with proposals affecting heritage assets, including non-designated heritage assets, priority over other policies in the LP will be afforded to the conservation of the assets affected and their setting as appropriate to the significance of the assets.

The proposal would also be contrary to London Plan 2021 (LDN) Policy D3.D(1) which requires development should in terms of form and layout, enhance local context by delivering buildings and spaces that positively respond to local distinctiveness and LDN Policy D3.D(11) which requires proposals to respond to the existing character of a place by identifying the special and valued features and characteristics that are unique to the locality and respect, enhance and utilise the heritage assets and architectural features that contribute towards the local character.

The proposal would also be contrary to the Supplementary Planning Document – [name] 2010 which requires extensions to dwellinghouses to harmonise with the scale and architectural style of the original building and should not dominate the original building or the surrounding streetscape.

The National Planning Policy Framework 2021 (the Framework) states, in paragraph 199, 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). This is irrespective of whether any potential harm amounts to substantial harm, total loss or less than substantial harm to its significance.

I find the proposal would result in less than substantial harm to the CA as a result of the visibility outlined above. In accordance with the Framework, paragraph 202, where a development proposal will lead to less than substantial harm to the significance of a designated heritage asset, this harm should be weighed against the public benefits of the proposal including, where appropriate, securing its optimum viable use. The proposal is for alterations to a private dwelling and I currently have no evidence before me to support that the proposal would result in any public benefits or is securing optimal viable use to outweigh the weight which should be given to the harm identified.

For the reasons outlined above, and taking account all other matters raised, I conclude that the appeal should be dismissed.