Part first floor rear extension

Appeal Decision Site visit made on 5 August 2026 by Chris Couper BA (Hons) Dip TP MRTPI an Inspector appointed by the Secretary of State Decision date: 14 August 2026 Appeal Ref: 6011484 148 Cardington Square, Hounslow TW4 6AL • 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 Chamkour Singh against the decision of the Council of the London Borough of Hounslow. • The application Ref is P/2025/3681. • The development proposed is a part first floor rear extension. Decision 1. The appeal is allowed and planning permission is granted for a part first floor rear extension at 148 Cardington Square, Hounslow TW4 6AL in accordance with the terms of the application, Ref P/2025/3681, subject to the following conditions: 1) The development hereby permitted shall begin not later than 3 years from the date of this decision. 2) The development hereby permitted shall be carried out in accordance with the following approved plans: PL2/SM/148-00 Rev A, PL2/SM/148-01 Rev A, PL2/SM/148-02 Rev A, PL2/SM/148-03 Rev A and PL2/SM/148-04 Rev A. 3) The materials to be used in the construction of the external surfaces of the development shall match those used in the existing building. Main Issues 2. The main issues are the effect of the proposal on: • the living conditions at 146 Cardington Square (‘No 146’), with particular regard to outlook and the availability of natural light; and • the character and appearance of the host property and the area. Reasons Living conditions 3. The host comprises a semi-detached two storey house, which is stepped slightly further back from the highway compared to the broadly similar neighbouring semi- detached pair at Nos 146 and 144. The proposed first floor extension would be located above part of the host’s existing flat-roofed rear projection on the side closest to No 146, and would be around 3 metres deep and 3 metres wide. Appeal Decision 6011484 2 4. Whilst that depth would be slightly greater than the 2.5 metre maximum recommended in Section 6 of the Council’s SPD1, the extension’s perceived bulk and mass would be limited by its matching hipped roof form, by its ridge which would be set well below the host, and by its lightly coloured rendered finish. 5. Moreover, No 146 also has a ground floor rear extension, and there would therefore only be obliquely angled views of the proposal looking above the existing tall solid gates from its ground floor rear windows. Given the staggered relationship between these two properties, the proposed extension would be more clearly visible from No 146’s nearest first floor rear window, but it would be off-set to the right beyond a shared driveway, and the principal outlook from there is straight down that property’s own garden. It would not therefore cause those occupants a harmful sense of enclosure. 6. For similar reasons, and having regard to the siting and orientation of these two properties, and the scheme’s finish and limited mass, it would not result in a significant loss of natural light within those rooms. 7. Amongst other things, and in general terms, Policies CC2 and SC7 of the Hounslow Local Plan 2015 - 2030 (‘HLP’) expect proposals to minimise harm to neighbouring residents by avoiding an unacceptable loss of outlook and daylight, or an unacceptable sense of enclosure; and to have regard to design guidance in Supplementary Planning Documents. By reference to the particular site circumstances and context here, the scheme would not harmfully impact neighbouring living conditions, and it would not therefore conflict with HLP Policies CC2 and SC7, or with the thrust of the advice in the SPD. Character and appearance 8. As well as advising a maximum depth of 2.5 metres, the SPD says that first floor rear extensions should be set down at roof level and should be less than half the width of the main house. In this case, the extension’s roof would be set well down below the original building’s ridgeline, but as well as being slightly deeper than advised, it would also be marginally wider. 9. However, given its siting, the scheme would be largely hidden from the Cardington Square streetscene, and in views from nearby gardens, it would appear to be around half the width of the original house. Along with its set down hipped roof, that would give it a reasonably proportionate and subordinate appearance, and its matching materials would help it to assimilate with the existing building. In the context of various alterations and extensions to nearby properties, including a first floor rear extension at 32 Cardington Square, it would not appear incongruous or out-of-place. 10. For these reasons, the proposal would not harm the character and appearance of the host property or the area. It would therefore accord with those parts of HLP Policies CC1, CC2 and SC7 which support high quality design, that responds to the site and the area’s character, and which set out that extensions should complement, and appear subordinate to, the existing building. Neither would it conflict with the broad thrust of the advice in the SPD. 1 Hounslow Character, Sustainability and Design Codes Supplementary Planning Document Part A5 (2024) Appeal Decision 6011484 3 Conditions and Conclusion 11. Whilst the appellant has cited planning decisions elsewhere within the borough, the Council disputes that they conflict with the advice in the SPD. Irrespective of those examples, having considered this scheme in this location on its planning merits, I find that it would not adversely impact the character and appearance of the host property or the area, and that it would not affect neighbouring occupiers’ living conditions to a harmful degree. 12. I have considered the matter of conditions against the tests in the National Planning Policy Framework. As well as the standard time limit, in the interests of certainty, I have imposed a condition requiring that the development be carried out in accordance with the approved plans. Finally, for the reasons set out in this decision, a condition is necessary requiring that the extension be faced with matching materials. 13. Having regard to all other matters raised, the appeal is therefore allowed. Chris Couper INSPECTOR