Appeal 3337502

The appeal is dismissed.

The site visit was undertaken by a representative of the Inspector whose recommendation is set out below and to which the Inspector has had regard before deciding the appeal.

The National Planning Policy Framework (the Framework) was revised during the life of the appeal. The substantive elements thereof as they relate to the appeal scheme have not changed. I have not therefore sought the views of the main parties.

The appeal site is in a conservation area, and I shall therefore pay special attention to the desirability of preserving or enhancing the character or appearance of that area in accordance with section 72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990.

The description of development as detailed on the application form has been amended in subsequent documents. I have used the description included on the appeal form, which describes the proposal accurately and concisely.

The main issues are the effect of the proposal on the character and appearance of [address], Beckenham Conservation Area (MWBCA) and valuable trees. Appeal Planning Officer APP/G5180/D/24/3337502

The MWBCA is predominantly characterised by detached properties of highly individual design, which are unified by their interwar construction period, neo-vernacular design and materials traditionally used and techniques employed in cottages, barns and building pre-industrial revolution. The MWBCA represents the architectural innovation of early twentieth century house building traditions in Britain which greatly contributes to its significance. There is an alternate variance of small plots with dwellings close to the road and large plots with detached dwellings set well back from the road. This has resulted in built frontages offset by green space, trees and lawns to view distant dwellings which gives an open and verdant feel that also contributes to the significance of the MWBCA.

The appeal property is characterised by its neo-vernacular design and being one of the original dwellings constructed in the inter-war period has considerable historic significance. The roof design also contributes to the architectural innovation of this time period. The existing garage is a simple and modest single storey structure, which does not unduly stand out within the street scene and appears subservient to the main property. These elements, along with its large front garden and abundance of greenery, mean the appeal property positively contributes to the significance of the MWBCA.

The garage would be demolished and replaced with a large extension to the side of the dwelling. Together with the large additions to the rear, the proposed extensions would fundamentally alter and fail to respect the historic composition of the appeal property. By reason of their excessive scale, bulk, height and massing, but also lack of sufficient set back in respect of the side extension, the proposed additions would harmfully dominate and overwhelm the host property and, in doing so, undermine its architectural integrity. Due to the scale of the proposal, the existing landscaping would not mitigate the visual impact of the development within the street scene.

The incongruity of the appeal scheme would be exacerbated by the introduction of an overly large crown roof which, although found elsewhere within the conservation area, would appear as an incongruous addition and detract from the historic character of the host building. As a result, the proposed additions would significantly erode the contribution which this property currently makes to the special interest of the MWBCA.

Despite the excessive width and scale of the proposed side extension, a sufficient degree of separation would be retained between the appeal property and [address], and the spacious character of the area would, in this respect, be largely preserved. The established planting along the shared boundary would also assist with softening the visual impact of the proposal in this regard, as it partially screens the gap from public view.

The proposed changes to the front garden would erode the site’s verdant character and the pleasant setting it currently provides for the appeal property. The loss of vegetation would increase the prominence and closeness of the main building to the road as it would no longer have the abundance of greenery, trees and lawn to offset its distance. The frontage would instead be Appeal Planning Officer APP/G5180/D/24/3337502 dominated by the hard surfacing, thus harmfully diminishing the site’s contribution to the area’s verdant character and softening of the street scene.

In considering other developments which have been constructed within the MWBCA, including crown roof additions, I acknowledge that each case must be assessed on its own merits. Despite their proximity to the appeal site, the circumstances of these particular schemes do not represent a direct parallel to the current proposal, notably with regard to national and development plan policy. In any event, it is my view that these neighbouring developments should not be used as a reason to allow further incremental harm to the special interest of the MWBCA.

Overall, the proposed extensions would have a harmful impact on the character and appearance of the MWBCA which, it follows, would not be preserved or enhanced. The appeal scheme would therefore be contrary to the Bromley Local Plan (January 2019) (LP) Policy 41, the London Plan (March 2021) Policy HC1 and Section 16 of the Framework, which require development proposals to preserve the significance of heritage assets, notably by respecting the existing building layout, scale and form and its surroundings. The proposal would also be contrary to LP Policy 37, which states that development will be expected to complement the scale, proportion, form and layout of the area, positively contribute to the existing street scene and respect heritage assets. Furthermore, the proposal would be contrary to LP Policy 6, which requires residential extensions to complement the scale, form and materials of the host dwelling.

There are several valuable trees in the rear garden, including a [name] (T8) and a [name] (T9). Both are mature, healthy specimen which, by reason of their form, height and size make a positive contribution to the verdant character and appearance of the MWBCA.

Concerns have been raised by the Council regarding the construction of a garden room in a location where tree protective fencing for T8 would need to be installed to enable the construction of the appeal scheme. The appellant has confirmed that the garden room does not form part of the appeal proposal. Whether or not the garden room could be constructed using permitted development rights, the impact this could have on protected trees, such as T8, would have to be carefully considered. That said, had the appeal proposal been considered acceptable in all other respects, this matter could have been addressed by imposing conditions to ensure that valuable trees are suitably protected during the construction phase and, in particular, any protective fencing is not removed until completion of the development.

Part of the proposed area to be levelled would occur within the root protection area of T9, therefore creating a ground level change which could cause root damage. As stated in BS 5837: 2012 (Trees in relation to design, demolition and construction - Recommendations), the arboricultural impact assessment should have regard to potentially damaging activities proposed in the vicinity of retained trees, such as changes in ground level. Having regard to the available information, I cannot be satisfied that the proposed changes in level would not have an adverse effect on the longevity and wellbeing of T9, especially as mature birch trees are known to be particularly sensitive to development impacts. Appeal Planning Officer APP/G5180/D/24/3337502

In the absence of detailed evidence to the contrary, there is a high likelihood that the proposed development would compromise the longevity of T9. The loss of this valuable tree would exacerbate the harm caused by the appeal scheme to the significance of the MWBCA. Consequently, the proposal would be contrary to LP Policy 43, which states development will not be permitted if it leads to the loss of one or more significant trees in a Conservation Area, and London Plan Policy G7, which states wherever possible existing trees of value are retained. It would also be contrary to LP Policy 73, which states that proposals are required to take particular account of existing trees on site, and LP Policy 77, which seeks to safeguard the quality and character of the local landscape.

Although a reasonable degree of separation would be retained to the side of the property, this is outweighed by the harm attributed to the proposed extensions and roof alterations, and loss of green space within the front garden as well as the potential harm to valuable trees. The appeal scheme would cause less than substantial harm to the significance of the MWBCA, to which I ascribe considerable importance and weight. In such circumstances, paragraph 208 of the Framework requires the harm to be weighed against the public benefits of the proposal. However, I have been presented with no public benefits which would outweigh the identified harm.

For the reasons given above and having had regard to all other matters raised, I recommend that the appeal should be dismissed.

I have considered all the submitted evidence and my representative’s recommendation and on that basis the appeal is dismissed.