Erection of single storey rear extension

Appeal Decision Site visit made on 26 May 2026 by E Clifford BA (Hons) MA Decision by M J Francis BA (Hons) MA MSc MClfA an Inspector appointed by the Secretary of State Decision date: 28th July 2026 Appeal Ref: 6007023 1 Sundridge Avenue, Bromley BR1 2PU • 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 Mr N Grayston against the decision of the Council of the London Borough of Bromley. • The application Ref is 25/05595/HPA. • The development proposed is the erection of single storey rear extension. 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 Issues 3. The main issues are the effect of the proposed development on the: • character and appearance of the host property and the surrounding area; and • the living conditions of the occupiers of the neighbouring property, No 1A Sundridge Avenue (No 1A), having particular regard to outlook and loss of sunlight. Reasons for the Recommendation Character and Appearance 4. The appeal site comprises a substantial detached dwelling set within a generous plot. It shares an access from the highway with No 1A, the adjacent property, which leads to a generous drive. As the appeal property is sited on a corner plot, it has a garden which wraps around the side of the dwelling with a shallow rear garden. The house is of a modern design and is part of a small group of three properties which appear to have been designed and built at the same time. There are elements, such as the projecting front gables and the two storey bay windows, as well as the materials palette, which have been inspired by the older houses on the same side of the road, and which create a harmonious appearance. 5. The rear garden is currently characterised by its verdant nature created by the mature trees and raised flower beds. However, despite the overall size of the plot, Appeal Decision 6007023 2 the rear garden is modest. The house is positioned very close to the neighbouring dwelling, No 1A, which has a similarly sized rear garden. 6. The London Borough of Bromley Urban Design Guide: Supplementary Planning Document (2023) advises that extensions should be subservient in scale to avoid uncharacteristically large additions which can significantly change the appearance of a property. The proposed development would result in a single storey extension and so would not compete vertically with the host building. The low level of the proposal and the orangery style design would complement the existing built form of the host property and its surroundings, with elements drawn from the wider street scene. The proposed materials would also match the host dwelling and would be acceptable. 7. However, the proposed development would extend from the rear elevation of the house to the rear boundary of the garden. Therefore, whilst the extension would be limited in height, because of its length, it would infill a large area of the rear garden. Although it would result in a modest increase in the overall floorspace of the house, it would significantly increase the floorspace on the ground floor which would appear excessive and disproportionate. In addition, sited in the corner of the garden, close to the boundary fence on one side and against it on the other, the structure would appear cramped and oversized, despite the general size of the plot. 8. I accept that the proposed development would not be visible from the street scene and harm the appearance of the surrounding area. However, this does not change my conclusion that the proposal would result in harm to the host dwelling as the scale of the proposal is excessive for its location within the plot. 9. The appellant has suggested that a fallback position exists as they have previously applied to the Council under Class A.1 (g)1 for an extension 8m in length from the rear wall of the house. Although prior approval was not required based on the size of extension specified, there is no lawful development certificate before me. Nevertheless, this would be smaller and less harmful than the proposed extension, as it would not extend up to the rear boundary. 10. Overall, I conclude that the proposed development would have a harmful effect on the character and appearance of the host property. It would therefore fail to comply with Policies 6 and 37 of the London Borough of Bromley Planning Division Local Plan (2019) (BLP) which requires, amongst other things, the scale, form, and materials of construction to respect or complement the host dwelling and the scale, proportion, form, and layout of adjacent buildings. It would further conflict with the requirements of Policy D3 of The London Plan (2021) (LP) which has a design-led approach to ensure development is of the most appropriate form for the site. Living Conditions 11. The neighbouring property, No 1A, has a wide but shallow rear garden, like the appeal site. It has a dense, verdant boundary to the rear and there is intervening greenery between it and the appeal site. Therefore, the garden experiences an existing level of overshadowing from the trees, shrubbery and from the bulk of the house. The existing outlook is characterised by the surrounding built form and boundary treatments. 1 The Town and Country Planning (General Permitted Development) (England) Order 2015 Appeal Decision 6007023 3 12. Because of the size of the extension, which would be constructed next to the boundary with No 1A, it would extend along the full length of No 1A’s rear garden. However, because the gardens rise to the rear, it would not be visible above the existing fence for the entire length. Given its single storey nature, and the generous width of the neighbouring garden, it would not be perceived as visually dominant or overbearing, nor as creating an excessive sense of enclosure. The proposed development would also be experienced within the context of the existing surrounding built form. Therefore, the addition of a single storey extension would not alter this to the extent that it would become harmful to the living conditions of the occupiers. 13. Similarly, the proposed development would not result in a notable increase in the level of overshadowing experienced in that area of the neighbouring garden given the natural path of the sun and the orientation of the plots. The neighbouring property has a wide rear garden which enjoys the sun at various parts of the day, despite the periods of shade due to the significant level of tree cover. The limited increase in overshadowing is not considered to be of a significantly harmful nature. 14. Therefore, I conclude that overall, the proposed development would not harm the living conditions of the occupiers of No 1A, having particular regard to outlook and sunlight. It would therefore comply with the requirements of Policy 37 of the BLP to respect the amenity of occupiers of neighbouring buildings and those of future occupants, and Policy D3 of the LP to deliver appropriate outlook, privacy, and amenity. Conclusion and Recommendation 15. For the reasons given above and having had regard to all other matters raised, I recommend that the appeal should be dismissed. E Clifford APPEAL PLANNING OFFICER Inspector’s Decision 16. I have considered all the submitted evidence and my representative’s report and on that basis the appeal is dismissed. M J Francis INSPECTOR