Demolition of existing side lean-to, conversion of garage to habitable space, new entrance porch, and part first floor front extension, single storey side, and part one/two storey rear extensions

Appeal Decision Site visit made on 27 October 2025 by F Bradford BA (Hons) MRTPI Decision by R Gee BA (Hons) Dip TP PGCert UD MRTPI an Inspector appointed by the Secretary of State Decision date: 30 January 2026 Appeal Ref: 6000364 5 Wimborne Avenue, Chislehurst, BR7 6RQ • The appeal is made under section 78 of the Town and Country Planning Act 1990 (as amended) against a refusal to grant planning permission. • The appeal is made by Ms Beth Owusu against the decision of the London Borough of Bromley Council. • The application Ref is 25/00682/FULL6. • The development proposed is demolition of existing side lean-to, conversion of garage to habitable space, new entrance porch, and part first floor front extension, single storey side, and part one/two storey rear extensions. Decision 1. The appeal is dismissed. Appeal Procedure 2. 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. Main Issue 3. The Council assert that the part first floor front extension, front porch and single storey side extension are acceptable. I see no reason to disagree. 4. The main issues are the effect of the proposed rear single and two-storey extensions on the living conditions of the occupants of 7 Wimborne Avenue with regard to outlook and their effect on the character and appearance of the host dwelling and area. Reasons for the Recommendation Living Conditions 5. The Council’s report refers to a range of issues relating to the living conditions of neighbouring occupants. However, the Council’s reason for refusal focuses on the effect of the proposed development on the outlook of neighbouring occupants. I have as such proceeded on this basis. 6. The appeal sites comprises of an existing detached two-storey dwelling with single storey additions. It lies proximate to neighbouring residential properties. The proposed development would replace an existing single storey rear extension with a two-storey development that would be positioned close to the shared boundary with No. 7. The shared boundary is formed of trees and vegetation. Appeal Decision 6000364 2 7. The proposal would introduce a substantial reward projection close the shared boundary with No 7. Whilst it would be set in from the shared boundary, it would nevertheless remain close. Notwithstanding its set down from the roof ridge of the host dwelling, by virtue of its scale and mass the proposal would result in an overly dominant feature when viewed from the rear first-floor windows of No. 7. This would be to the detriment of the outlook for neighbouring occupants. Furthermore, it would have an overbearing effect to the portion of their rear garden closest to the dwelling. This impact would be exacerbated by the difference in ground level between the appeal site and neighbouring property, which would consequently mean that the rear extension would appear even taller. 8. Whilst the development may be partially screened by the existing trees and vegetation, a substantial portion would not be. In any event, the existing trees/vegetation would not provide a permanent nor securable mitigation against the harm identified. 9. Whilst the appellant states that the Council’s viewpoint is not substantiated by technical evidence, I am satisfied, on the basis of the evidence before me and what I have observed on my site visit, that the proposal would result in the harm identified above. I am however satisfied that the proposal would not result in a loss of privacy due to the absence of any first floor windows facing toward No 7. Furthermore, whilst there is an existing extension to the rear of the host dwelling it is single storey. As such, its impacts are materially different to that of the proposed development which is two storeys. 10. For these reasons, I find the proposal would result in harm to the living conditions of No 7 by way of overbearing and loss of outlook. As such, I find conflict with policy 37 of the Bromley Local Plan (2019) (BLP) and D3 of the London Plan (2021) (LP). These Policies, among other things, aim to ensure acceptable impact to neighbouring properties by way of overshadowing, loss of light, overbearing impact, overlooking, loss of privacy and general noise and disturbance. Character and Appearance 11. The appeal site comprises a detached two storey dwelling set back from the highway to accommodate off-street parking and is located within the Marlings Park Estate Area of Special Residential Character. The surrounding area has a strong suburban character with evident references to the Arts and Crafts movement. Forms and massing of dwellings vary in the locality due to different designs and/or the evolution of their forms as a result of alteration and extension. Nevertheless, properties are generally unified by a consistent palette of materials. Within this specific part of Wimborne Avenue, there is a sense of openness and spaciousness afforded through properties’ setback from the highway and gaps between buildings, which allow glimpsed views between. Landscaped front gardens also contribute positively to the quality of the character and appearance of the area. 12. The proposed development would introduce a substantial extension to the rear elevation of the appeal dwelling, comprising part single, and part two-storey elements. The overall bulk of the proposed extension would represent a substantial enlargement to the property currently in situ. However, it would read clearly as an extension of varying elements. Furthermore, the rear garden of the appeal site is generous, and the proposed development would not occupy a substantial amount of the plot. Appeal Decision 6000364 3 13. Accordingly, the proposed development would preserve the established visual hierarchy on site, with the extension appearing overall subservient to the host dwelling. Although the development would alter the host dwelling’s massing, it would not diminish its positive contribution to the streetscape, owing to the existing variety of dwelling types and the continued use of materials that maintain visual unity. 14. For these reasons, I find the proposal would not result in harm to the character and appearance of the host dwelling and area. As such, I find no conflict with policies 6, 37 and 44 of the BLP or D3 of the LP. These Policies among other things, aim to ensure development respects the scale, form and materials of the host dwelling and surrounding area, positively contributes to the existing street scene, and respect the special distinctive qualities of Areas of Special Residential Character. Other Matters 15. The appellant has drawn my attention to development in support of this appeal. Whilst the development at 36 Marlings Park Avenue (No 36) may include a two- storey element, the Inspector’s acceptance of that scheme was caveated by factors that are not present in this appeal. Based on the evidence before me, No 36 and its affected neighbour benefit from a greater separation distance and different building placements than in the appeal scheme. Therefore, the resulting effect is materially distinct from that of the appeal scheme, and I attach this only limited weight. 16. The developments at 22 and 31 Berens Way are described exclusively in their descriptions of development as single storey, which are reflected in their plans and aerial images provided by the appellant. Given that the cause of harm arising from the appeal scheme relates to the two storey element, I find no substantiation to form a comparative basis of the effects of the development on living conditions of neighbouring occupiers given that they are materially different in terms of their height and I as such attach this only limited weight. 17. I have found no harm to the character and appearance of the host dwelling and area or on living conditions with regard to privacy within this appeal. Accordingly, it is unnecessary to comment on the appellant’s examples of development which relate this matter. These include 7, 9,14, and 32 Wimborne Avenue, and 33 Berens Way, which are as such attached insignificant weight. 18. I recognise the appellant’s motivations to pursue the proposed development, including the provision of additional living space and the modernisation of the dwelling. Whilst benefits may arise from the development, including employment opportunities through the construction phase this would be temporary in nature. Furthermore, by reason of the scale of the proposed development I attach only limited weight to the benefits of the scheme. Appeal Decision 6000364 4 Conclusion and Recommendation 19. My above findings bring the proposal into conflict with the development plan, read as a whole. There are no material considerations that indicate a decision should be made other than in accordance with it and the harm arising is not outweighed by similar development, the appellants personal circumstances, or the benefits of the scheme. Therefore, I recommend that the appeal should be dismissed. Finlay Bradford APPEAL PLANNING OFFICER Inspector’s Decision 20. I have considered all the submitted evidence and my representative’s report and on that basis the appeal is dismissed. R Gee INSPECTOR