Appeal 3341518

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.

A new version of the National Planning Policy Framework (the Framework) was published in December 2024. [name] have had regard to the revised national policy as a material consideration, planning decisions must still be made in accordance with the development plan unless material considerations indicate otherwise. In this instance, the issues most relevant to the appeal remain unaffected by the revisions to the Framework. I am therefore satisfied that there is no requirement to seek further submissions on the revised Framework, and that no party would be disadvantaged by such a course of action.

The appeal site is located within the Keston Park Conservation Area (CA). I shall therefore have regard to section 72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990.

The main issue is the whether the proposal would preserve or enhance the character or appearance of the CA, having particular regard to protected trees.

As noted in the Supplementary Planning Guidance for Keston Park (adopted

the CA derives particular significance from the large, distinctive private homes which are laid out in a style reminiscent of an American suburban development. Furthermore, the landscape of the park adds to the significance of the CA, as it features many mature trees which were preserved when this Appeal Planning Officer APP/G5180/D/24/3341518 high quality residential area was developed, creating a pleasant and verdant woodland setting.

The appeal site, no [site address] (no 55) comprises a large, detached two-storey dwelling located on the eastern side, near the southern end of [name], which is a private residential estate featuring similarly sized properties. The rear garden of no 55 is of a generous size and contains several existing structures, such as sheds, greenhouses, and summer-house-style buildings, primarily positioned towards the corners. Additionally, the garden boasts several trees, including three prominent Scots pine trees that stand out due to their size and positioning. These trees are visible from various points along [name], and due to a combination of their height and maturity, contribute positively to the verdant character and appearance of the CA. For these reasons, the appeal site makes a positive contribution to the significance of the CA.

The Council’s concerns relate specifically to the effect the proposal would have on the nearby trees and I therefore will restrict my further consideration to this aspect of the proposal. An Arboricultural Impact Assessment (AIA) was submitted with the application, identifying the Scots pine trees on the site as T4, T5, and T8, and classifying them as [name] – trees of moderate value and quality, whose retention is desirable due to their significant contribution.

The proposed outbuilding would be centrally located between trees T5 and T8, as noted in the AIA, and would encroach into their respective [name] (RPA). This could cause harm to the longevity, health, and wellbeing of the trees. The appellant has claimed that any potential harm would be minimised through the use of a specific foundation design, which includes a reinforced concrete slab elevated above ground level, along with a gravel bed and a permeable membrane beneath the suspended floor. The appellant asserts that these designs comply with the guidance outlined in BS 5837:2012 – Trees in relation to design, demolition, and construction.

However, as clearly set out by BS 5837:2012, the default position should be that structures are located outside the RPAs of trees to be retained. It is only where there is an overriding justification for construction within the RPAs that technical solutions should be envisaged. In this instance, it remains for example unclear whether alternative design solutions were considered to avoid constructing the proposed development within the RPAs of T5 and T8. Furthermore, no detailed evidence has been presented to demonstrate that the trees would remain viable and that the areas lost to encroachment would be compensated for elsewhere, and no mitigation measures have been proposed to improve the soil environment used by the trees.

The Council has suggested that debris from the pine trees would result in regular maintenance issues and place unnecessary pressure on preservation objectives. However, the debris from the pine trees could be dealt with as part of the ongoing management of the garden and, having regard to the available evidence, I am not certain that this would lead to future pressure to fell the trees.

Overall, despite the technical construction solutions proposed, I find that building the development within the RPAs would be unacceptable and would jeopardise the long-term health of the trees. Given their significant visual Appeal Planning Officer APP/G5180/D/24/3341518 presence, the loss of these trees would harm the character and appearance of the locality.

The proposal would cause less than substantial harm to the significance of the CA, to which I ascribe considerable importance and weight. In such circumstances, paragraph 214 of the Framework states the harm should be weighed against the public benefits of the proposal, including, where appropriate, securing its optimum viable use. The proposed development would provide additional living accommodation for use as a home gym, but this would primarily benefit the occupiers of the appeal premises. Overall, there are no presented public benefits which would outweigh the identified harm.

For the reasons given above, the proposal would fail to preserve the character and appearance of the CA. Consequently, the proposal would contravene Policies 37, 43, and 73 of the Bromley Local Plan (adopted 2019). Amongst other things, these policies seek to ensure that development respects landscape features, protects significant trees in Conservation Areas, and considers existing trees on site. Additionally, it would conflict with Policy 19 of the Bromley Tree Management Strategy (adopted 2023) and Policy G7 of The London Plan (adopted 2021), both of which emphasise the retention of existing trees in development.

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.