Part roof extension over outrigger

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: 6004448 25 South Western Road, Richmond upon Thames, Twickenham, TW1 1LG • 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 Darragh Kilroy against the decision of the Council of the London Borough of Richmond upon Thames. • The application Ref is PA25/3596. • The development proposed is described as ‘part roof extension over outrigger’. Decision 1. The appeal is allowed and planning permission is granted for an L-shaped rear dormer at 25 South Western Road, Richmond upon Thames, Twickenham, TW1 1LG in accordance with the terms of the application, Ref PA25/3596, and the plans submitted with it. Background 2. In June 2025 planning permission was granted for development at 25 South Western Road described as ‘Proposed single storey rear wraparound extension, rear dormer roof extension above rear roof slope and outrigger, and two skylights to the front roof slope’ (Ref PA25/1307). 3. In September 2025 a Certificate of Lawful Use or Development (LDC) was issued for works to the appeal property described as ‘Proposed loft conversion with 3no. Roof lights to front roof slope and dormer to rear roof slope with external doors and juliet balcony’ (Ref PA25/2699). The planning application to which this appeal relates was made in October 2025. Procedural Matter 4. At the time of my visit, I saw that a composite roof extension had been constructed at the appeal property comprising an L-shaped dormer spanning the rear roof slope and extending over the dwelling’s rear outrigger. The works were substantially complete externally at roof level apart from a boarded rear facing opening for a window/door. 5. The drawing accompanying the planning application relating to this appeal entitled ‘Existing Elevations & Sections’ (Drg No 02) showed the property unextended at roof level to the rear, save for two roof lights. The drawing entitled ‘Proposed Elevations & Section’ (Drg No 04), showed a composite roof extension, similar to that which has been built, and included external doors and a Juliet balcony. There Appeal Decision 6004448 2 is no evidence before me to demonstrate that a dormer extension to the rear roof slope in isolation and with external doors and a Juliet balcony, in accordance with the LDC, had been constructed and completed before the composite roof extension was built. Therefore, notwithstanding the limited description of the extent of the proposed development that was given on the planning application form, or that a Building Control Initial Notice was submitted to the Council in September 2025 for works including a loft conversion, I have considered the appeal based upon the entirety of the works that are shown on the application drawings. This is reflected in my formal decision which uses the description of development that was given on the Council’s decision notice. Main Issues 6. The Council has confirmed that the form of the dormer proposed under this appeal, and which is constructed and largely complete, matches that approved under PA25/1307. The only difference between that approved and that which is now proposed is the inclusion of external doors and a Juliet balcony upon that part of the extension over the original rear roof slope. Therefore, in light of the extant planning permission, I consider the main issues to be the effects of the proposal, having particular regard to the external doors and Juliet balcony, upon the character and appearance of the area and upon the living conditions of neighbouring occupiers with regard to privacy. Reasons 7. The appeal property is a mid-terraced, two-storey dwelling with a rear outrigger within a residential neighbourhood comprising properties of similar type and age. During my visit, I observed that L-shaped dormer windows were commonplace to the rear elevations of properties surrounding the appeal site, including at the handed neighbouring property at No 27. These all include a variety of sizes and styles to window and door openings at roof level, including Juliet balconies, as is recognised by the Council within the officer’s report. 8. The Council’s House Extensions and External Alterations Supplementary Planning Document (SPD) was adopted in May 2015. In relation to roof extensions, it advises that, amongst other things, dormer extensions should have windows smaller than that of windows to the floor below. 9. The proposed double doors at roof level would reflect a similar vertical emphasis to the fenestration pattern of the property’s first and ground floor windows which are aligned immediately below. Although the combined form of the two doors would be slightly wider than the windows below, the difference in proportions would be only marginal and would not, to my mind, appear incongruous or out of keeping within the context of its rear garden setting, particularly having regard to how the roofscapes of the terraces along South Western Road and its surroundings have evolved. I find no conflict here with the aims or objectives of the SPD. 10. The Juliet balcony would not provide any external platform beyond the new floorspace that has been created within the original roof void, and which has the benefit of a planning permission with a rear facing window in the same position (Ref PA25/1307). As a consequence, I am not persuaded that any outlook from a set of inward opening doors at this level would result in a significantly different impact upon levels of privacy experienced by any neighbouring occupiers within their back yards, including those backing onto the appeal property along St Margaret’s Grove. Appeal Decision 6004448 3 My findings on this particular matter are informed by further consideration of the innumerable roof extensions surrounding in various forms, including other examples of Juliet balconies. 11. Overall, I am satisfied that the inclusion of double doors and a Juliet balcony on the rear dormer would not harm the character or appearance of the area, or the living conditions of any adjoining or nearby occupiers. As such, I find no 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, or with the Local Plan’s Policy 46 as far as it requires development to protect the amenity and living conditions for occupants of new, existing, adjoining and neighbouring properties. For the same reasons there would be no conflict with the National Planning Policy Framework’s policy requirements for achieving well- designed places. Conclusions 12. For the reasons given above, the appeal is allowed. As the development is substantially complete, I have no reason to impose any conditions. John D Allan INSPECTOR