Appeal 3304591

The appeal is dismissed.

The main issues are the effect of the proposal on: • The character and appearance of the host dwelling and local area and whether it would preserve or enhance those of the [address], Petts Wood Conservation Area (the CA); and • The living conditions of neighbouring residential occupiers with reference to light and outlook.

The host dwelling sits on a relatively large plot and two storey four bedroom detached house with gabled side ends, with a pitched roof with two engaged gable dormers to the front roof slope. A detached single garage sits to one side. It is located in an area of similarly scaled early 20th Century houses on large plots and English vernacular character in a variety of forms and designs that, along with the abundance of mature trees define the significance of the CA.

I have a statutory duty under section 72 of the Planning (Listed Buildings and Conservation Areas) Act 1990 to pay special attention to the desirability of preserving or enhancing the character or appearance of the CA.

The proposed single storey rear extension would appear as a proportionate and subservient addition to the existing house that would not fundamentally alter its character or appearance. The proposed two storey side extension would, however, add significant additional bulk to the existing house.

The proposed two storey side/rear extension would require the demolition of the existing small single storey detached garage, which reflects the character and appearance of the host dwelling and those of the CA. The flank wall of this existing garage sits on the boundary of the appeal property with the neighbouring property at [address] (No.248). The proposed side and rear extension would replace existing detached garage with a single integral garage at ground floor level and would, along with the proposed rear extension, allow for substantial reworking of the interior of the host dwelling as a four bedroom house.

The proposed side and rear extension would almost align with the front elevation of the host dwelling and would align with the existing rear ground floor elevation. It would add a third engaged dormer to an extended roof that would be at the same height as existing but would introduce a small crown and hipped end. This would replace the existing gable end at this side of the appeal dwelling, and the flank wall of the proposed extension would be approximately 1 Metre from the side boundary with No.248. Notwithstanding that the proposal would be constructed from materials matching those of the host dwelling, the bulk of the proposed side extension would substantially alter and unbalance the appearance of the host dwelling. This would not reflect the existing composition and massing of the appeal dwelling, thereby interrupting and diminishing the quality of its architectural expression.

Further, the extent of the side extension and its proximity to the boundary with No.248 would substantially infill the existing gap at first-floor and roof level between the house at No.248 and the host dwelling. Whilst policy 8 of the Bromley Local Plan (2019) (the BLP) normally requires that for a two storey building a minimum 1 Metre side space should be retained, it also sets out that where higher standards of separation already exist, and, notwithstanding the positioning of the existing single storey garage, that is the case here, proposals will be expected to provide a more generous side space. The proposal would, therefore, result in the extended host dwelling appearing as a significantly more substantial house too large for its plot, rather than as appearing as a subservient addition to the host dwelling.

The proposed two storey extension would also significantly restrict the space between these neighbouring houses, which currently display the staggered layout and generous spatial standards, with opening between that allows through views to mature trees and verdant gardens that contribute to the significance of the CA. The proposed infilling of this space and the bulky appearance of the side extension would unbalance the composition of the host dwelling and its visual relationship with the immediate neighbour at No.248, consequently failing to preserve the character or appearance of the CA.

Due to the staggering of houses on neighbouring plots in the existing layout of housing in the local area, No.248 is set forward of the host dwelling on its plot. This would result in the proposed two storey side/rear extension and single storey rear extension projecting approximately 5.7 Metres beyond the rear of this neighbouring house. Given the proximity of the proposal to the boundary between the two properties this would result in the proposal appearing as an enclosing and overbearing presence in the outlook from the rear rooms and garden of No.248.

The scale of the proposal, its proximity to the boundary and the orientation of the neighbouring houses would result in some loss of light to the rear rooms of No.248. Whilst this would not appear to be so significant in itself to refuse planning permission, when combined with the effect on outlook detailed above, the proposal would be experienced by the occupiers of No.248 as oppressive.

For the reasons given above the proposed development would harm the character and appearance of the host property and fail to preserve those of the CA. Further, it would also result in significant harm to the living conditions of the residential occupiers of No.248. This would not accord with the design advice given in the Council’s supplementary planning guidance for General Design, [name] and the Conservation Area and would conflict with policies 6, 37 and 44 of the BLP, policies D3, D6 and HC1 of the London Plan (2021) and sections 12 and 15 of the Framework. These collectively seek to ensure that development is of a high design quality, does not undermine the quality of life of neighbouring occupiers, integrates with the local area and preserves or enhances the significance of the CA.

Following the advice in paragraph 202 of the Framework, my balanced judgement is that the proposal would result in less than substantial harm to the character and appearance of the CA. Whilst this harm would be less than substantial, I must nonetheless give this considerable importance and weight in the context of a duty to favour preservation or enhancement.

The Framework states that 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. In this case the harm to the CA and the other harm that I have identified above would outweigh the benefits of the proposal, which appear to be mainly private ones and not necessary to realise the optimum viable residential use of the property.

The examples provided by the appellant of developments elsewhere have been considered. However, these do not alter the harm I find from this proposal, which must be assessed on its own merits. Therefore, for the reasons set out above, I conclude that the appeal should be dismissed.