Erection of extension to existing outbuilding in the rear garden (Retrospective Planning Application)

Appeal Decision Site visit made on 9 June 2026 by S Manson DipTP MRTPI Decision by John Morrison BA (Hons) MSc MRTPI an Inspector appointed by the Secretary of State Decision date: 6th July 2026 Appeal Ref: 6008625 54 Copperfield Avenue, Uxbridge UB8 3NX • 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 Faisel Ali against the decision of the Council of the London Borough of Hillingdon. • The application Ref is 14521/APP/2025/2799. • The development proposed is described as “erection of extension to existing outbuilding in the rear garden (Retrospective Planning Application)”. Decision 1. The appeal is allowed and planning permission is granted for development described as “erection of extension to existing outbuilding in the rear garden (Retrospective Planning Application)” at 54 Copperfield Avenue, Uxbridge UB8 3NX in accordance with the terms of the application, Ref 14521/APP/2025/2799, subject to the following condition: 1) The development hereby permitted is as shown on the approved plans reference: Location + Block Plan As Existing, 1253- PLA- 300_B and Existing Elevations, 1253- PLA- 301_B. Appeal Procedure and Main Issue 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 scheme, which seeks retrospective planning permission. The main issue in regard to which is its effect on the character and appearance of the area. Reasons for the Recommendation 3. The appeal property comprises a large, subdivided dwelling situated within a predominantly residential area. The surrounding pattern of development is notable for the presence of exceptionally generous rear gardens, particularly those serving properties on Copperfield Avenue and Micawber Avenue which back onto the appeal site. The appeal development relates to a flat-roofed extension to an existing outbuilding positioned toward the rear of this extensive garden area. 4. Owing to the considerable depth and scale of the host plot, the outbuilding, even with the addition of the extension, occupies a relatively modest proportion of the overall garden and sits comfortably within its spacious setting. Furthermore, the outbuilding is positioned well away from the main dwelling and is not readily visible from public vantage points. Several outbuildings of varying sizes and forms within Appeal Decision 6008625 2 the wider locality reflect a degree of variation in such structures. In this context, the extension presents as a low-level addition which does not appear unduly prominent or incongruous within the surrounding context. Consequently, it does not harm the character or appearance of the area. 5. Accordingly, it complies with Policy BE1 of the Hillingdon Local Plan: Part One - Strategic Policies, 2012 and Policies DMHB 12 and DMHD 2 of the Hillingdon Local Plan: Part Two - Development Management Policies, 2020. Amongst other things, these seek to ensure new development respects local character, taking into account scale, height, mass and bulk of adjacent structures, and is proportionate to the footprint of the dwelling house and to the residential curtilage in which it stands. Other Matters 6. The appeal seeks to regularise the extension. Any planning permission granted therefore does not affect the building’s use. Changes in this respect would be for the Council to enforce and/or invite a planning application for should they require such. This would be subject to assessment and consultation. From what I could see, the structure appears sound. However, matters relating to integrity in this respect and any concerns thereon, being mindful of the purpose of the appeal scheme, are addressed through the Building Regulations regime, which operates separately from the planning system. 7. Appeal 3353221 relates to a Certificate of Lawful Use or Development application and turns on its own site-specific circumstances. In contrast to the scheme before me, that appeal appears to have resulted in a more prominent form, resulting in a building with a larger footprint than the host dwelling. Conditions 8. Works in pursuant of the appeal have been completed, so a time condition is not required. I have set out one requiring the development to accord with the approved plans for enforcement purposes. Restricting the use of the building would not be reasonable as the scheme relates to its extension. The planning permission being granted is not for a change of use. Conclusion and Recommendation 9. For the reasons given above, the appeal scheme complies with the development plan. I therefore recommend that the appeal should be allowed. S Manson APPEAL PLANNING OFFICER Inspector’s Decision 10. I have considered all the submitted evidence and my representative’s report and on that basis the appeal is allowed. Planning permission is therefore granted, subject to the condition stated. John Morrison INSPECTOR