Erection of a first-floor rear extension, loft conversion with new dormer and new front porch

Appeal Decision Site visit made on 18 March 2026 by John D Allan BA(Hons) BTP MRTPI an Inspector appointed by the Secretary of State Decision date: 27 March 2026 Appeal Ref: 6004580 34 Bolton Gardens, Teddington, Richmond upon Thames, TW11 9AY • 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 and Mrs Jonathan and Lauren Jones against the decision of the Council of the London Borough of Richmond upon Thames. • The application Ref is PA25/3265. • The development proposed is the erection of a first-floor rear extension, loft conversion with new dormer and new front porch. Decision 1. The appeal is dismissed. Procedural Matter 2. Two appeals were submitted at the same time and on the same site. They relate to two separate proposals for 34 Bolton Gardens, each independent of the other. Each appeal has been considered as a separate entity. Appeal Ref 6004637 relates to a proposal for the erection of a ground floor rear extension and is the subject of a separate decision. Main Issue 3. The main issue is the effect of the proposal upon the character and appearance of the appeal property and wider area. Reasons 4. The appeal relates to a two-storey, detached dwelling on the west side of Bolton Gardens towards its southern end. The area comprises a residential suburb of mostly detached and semi-detached dwellings of the late Victorian to Edwardian period, set close to each other and behind fairly short frontages. There are a mix of property styles along Bolton Gardens but with notable clusters of repeat designs at intervals. No 34 is at the southern end of a small group of seven similar properties (Nos 22-34) with hipped roofs and forward projecting two-storey gabled bays. To the opposite side there is a group of four detached dwellings (Nos 36-42) with a distinctly different form comprising dual pitched roofs with gabled side elevations, each with a forward projecting gabled feature. The proposal would involve a significant remodelling of No 34 by projecting the two-storey form of the building to the rear with a first-floor 2m deep extension and by modifying the roof form and Appeal Decision 6004580 2 front façade to reflect the height and architectural style of No 36 and its contemporaries. Part of the proposal would include a rear facing box dormer. 5. The Council’s House Extensions and External Alterations Supplementary Planning Document (SPD) was adopted in May 2015. In relation to side and rear extensions it advises that their overall shape, size, and position should not dominate the existing house or its neighbours and that they should harmonise with the original appearance. In relation to roof extensions, it advises that, amongst other things, hip to gable extensions are not desirable and will not be encouraged, that extensions should be ‘in-scale’ with the existing structure and should not dominate the existing roof, and that dormers should have windows smaller than that of windows to the floor below. 6. The Council correctly point out that the proposed hip-to-gable change and raised ridge height would run counter to guidance contained within the SPD. However, gabled roofs with a ridgeline parallel to the road are commonplace along Bolton Gardens. Moreover, the remodelled form of No 34, when viewed within the street scene, would directly mimic the scale and appearance of the neighbouring group at Nos 36-42, including with modifications at ground floor. I share the appellants’ view that the alterations to No 34 would merely transition the point of obvious change which already exists between neighbouring properties. Rather than visually aligning with Nos 22-32, the appeal property would instead align with Nos 36-42. I am unable to identify how this would result in any harm to the character or appearance of the street scene. 7. To the rear, the Council has no objection to the first-floor rear extension. I am satisfied that it would appear as a fully integrated part of the dwelling’s remodelled form. 8. The dormer window would be set up from the eaves, down from the new ridge and in from both sides of the new gabled roof. I accept that it would be framed on all sides by the rear roof slope. However, for two principal reasons I share the Council’s concern that it would appear large and incongruous within its setting, representing a form of development the SPD specifically advises against. 9. Firstly, the proposed rear elevation, as shown on Drg No 112 Rev A, appears to show the dormer’s façade to be rendered. Notwithstanding the glazed elements, in my judgement this would contrast sharply with the tiled roof and would draw the eye, focusing attention upon its scale and presence, giving the impression more of an extra storey at second floor rather than a sensitive addition to the roof. 10. Secondly, due to their size and appearance, I find the row of three vertically proportioned window frames in distinctly classical Georgian style with curved fanlights would add a further degree of incongruence at an elevated level. Although they would match the window style proposed for the ground floor rear extension, that proposal is stand alone. In any event, the roof dormer would be seen in isolation from beyond the appeal site, not only in views from the backs of surrounding properties, but also in oblique views from Cromwell Road, as I observed during my visit. 11. I am mindful of other large dormer extensions nearby, including at No 36 next door. However, my findings are based upon the specific details of the proposal that is before me. I am not persuaded that the visual impact of the proposed dormer would Appeal Decision 6004580 3 directly compare with anything that I saw during my visit, or with any of the examples that have been presented to me. 12. Overall, by reason of the size and appearance of the dormer window, I find the proposal would be harmful to the character and appearance of No 34 and the wider area. As such, there would be conflict with Policy 28 of the Richmond upon Thames Local Plan (2024 to 2039), adopted in 2025, as far as it seeks to ensure development is compatible with local character. For the same reasons there would be conflict with the National Planning Policy Framework’s policy requirements for achieving well-designed places. 13. The appellants have directed me to a Certificate of Lawful Use or Development (LDC) which was issued on 5 March 2026 for works described as ‘Hip to gable end loft conversion with 2 rear dormers and roof lights’ (Ref PA26/0263). I have been provided with a set of plans which show the extent of the works that could be undertaken as permitted development. It is clear from these that the style of those alterations differs significantly from those that are before me as part of this appeal, including the size and appearance of the rear roof extension. Whilst I acknowledge the LDC represents a legitimate fallback position, the weight I attach to this does not outweigh the harm that I have identified and does not alter my findings relating to the proposed rear dormer window. Conclusion 14. For the reasons given above, the appeal is dismissed. John D Allan INSPECTOR