Single-storey rear extension

Appeal Decision Site visit made on 9 March 2026 by R C Shrimplin MA(Cantab) DipArch RIBA FRTPI FCIArb MCIL an Inspector appointed by the Secretary of State Decision date: 31 March 2026 Appeal Reference: APP/Q5300/D/25/3376180 25 Grange Park Avenue, Southgate, London N21 2LP • 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. A. Ioannou against the decision of Enfield Council. • The application reference is 25/02270/HOU. • The development proposed is a single-storey rear extension. Decision 1. The appeal is dismissed. Preliminary points 2. The “Description of Proposed Works” that is given in the planning application form is very extensive and it includes proposed construction details. Notwithstanding this description, therefore, the nature of the proposal can more clearly and succinctly be expressed, as set out in the Council’s decision notice and in the appeal form, as a “single-storey rear extension”. That is the description that I have adopted in the banner heading, above. 3. In the reasons for refusal, the Council draw attention to discrepancies in the drawings and the Appellant has submitted further drawings, in response to my request for comments. I have considered these additional drawings within the body of this Decision (below). Main issues 4. The first main issue to be determined in this appeal is the effect of the proposed development on the character and appearance of the host building and its surroundings. The second is the effect of the proposed development on the residential amenities of neighbours (whether unacceptable harm would be caused by overbearing appearance or overshadowing). Reasons 5. The appeal site is located in an extensive suburban area of North London. The locality is predominantly residential in nature and Grange Park Avenue is a wide road, set with mature trees in the footpaths. It is lined with semi-detached houses, behind front gardens that combine parking spaces and some planting. 6. Number 25 Grange Park Avenue is a semi-detached house in the same style as others in the road frontages. It is constructed primarily of red brickwork, under a Appeal Decision: APP/Q5300/D/25/3376180 2 hipped, tiled main roof, with a dominant bay feature on the front elevation. The site has a parking space on the front garden area and a single garage at the rear, accessed by means of a shared access between numbers 25 and 27. The property has the benefit of a good rear garden, which is mostly laid to grass, with a terraced area adjacent to the house. The ground slopes away from Grange Park Avenue, and the back garden is at a lower level than the rear part of the house. 7. It is now proposed to construct a single-storey rear extension to the house, which would add to the “rear reception room”. 8. The ‘National Planning Policy Framework’ emphasises the aim of “achieving well designed places” in the broadest sense (notably at Section 12), while making effective use of land and encouraging economic activity. It is aimed at achieving good design standards generally, by adding to the overall quality of the area and being visually attractive and sympathetic to local character and history, although it is also recognised that appropriate change may include increased densities. The achievement of good design includes protecting existing residential amenities and providing good standards of accommodation in new development. 9. Policies in the Development Plan also share these basic principles. In particular, Policies D3 and D4 of ‘The London Plan’ (dated March 2021) promote a “design-led approach” and emphasise the importance of “delivering good design”. 10. Similarly, Policies in the ‘Enfield Core Strategy’ and the ‘Enfield Development Management Document’ promote good design, notably at Policy CP30 of the former and Policies DMD6 and DMD37 of the latter. Policy DMD11 of the ‘Enfield Development Management Document’ is specifically concerned with “Rear Extensions” and likewise identifies some specific design considerations, including the need to protect the “amenities of the original building and its neighbouring properties”. 11. As shown on the application drawings, the proposed extension would project by 5.3 metres beyond the rear of the main part of the existing rear elevation of the house. It would be constructed of brickwork, with a shallow pitched roof, sloping away from the rear of the house. Alterations are proposed to the existing garage, effectively changing it from a vehicle garage to a more general residential ancillary use. 12. The Council have criticised the accuracy of the drawings in certain respects: in connection with the site levels and the relationship between the existing garage building and the proposed extension. In consequence, the proposed rear elevation is plainly inaccurate and ground levels are not shown clearly, for example. 13. The new drawings that have been submitted during the course of this appeal are markedly different from those that were submitted with the planning application and they do not show all the elevations of the proposed extension. If the appeal were to be allowed, it would not be possible for me to impose a condition requiring compliance with the new drawings, since that would change the nature of the proposal, without it having been considered properly through the usual application procedure. I have formed the opinion, therefore, that I must rely on the previously submitted drawings. 14. The proposed rear extension would have a long, sloping roof that would finish just beneath the first floor window cill of the existing house. This would create an Appeal Decision: APP/Q5300/D/25/3376180 3 unattractive and ungainly structure, architecturally, with a considerable bulk on the boundary. 15. The proposed extension would project well beyond the rear of the original house, adding a high flank wall on the boundary with number 23. The natural ground level slopes away from the rear of the houses, but the elevation drawings do not recognise this level change, continuing the ground floor extension at the same floor level as the existing ground floor. As a result of the change in levels, combined with the increased height of the sloping roof, a high wall would be created on the boundary. In consequence, I have concluded, on the evidence before me, that an unacceptably long, high wall would be created on the boundary with number 23, which would intrude on the outlook of that neighbouring property. 16. Although the boundary wall would have some effect on the neighbour’s sunlight and daylight, it would be located to the north-west of the adjoining garden and this issue would be of less concern than the visual intrusion and the overbearing nature of the extension. 17. Evidently, the appeal site lies within an established urban area, which is “sustainable” in planning terms, and the proposed development would make a useful addition to the existing house. Nevertheless, I am convinced that the harm that would be done to the character and appearance of the host building and the effect of the proposed development on the residential amenities of neighbours clearly outweigh the benefits. 18. Hence, I have concluded that the scheme before me would conflict with both national and local planning policies (including the Development Plan) and that it ought not to be allowed. Although I have considered all the matters that have been raised in the representations, I have found nothing to cause me to alter my decision. 19. In reaching these conclusions I have considered whether the appeal could be allowed but subject to conditions that might overcome the concerns that I have identified. In view of all the uncertainties involved, however, I have formed the opinion that it would not be possible to frame precise conditions to deal with the objections that I have identified and that therefore this appeal must be dismissed. Roger C. Shrimplin INSPECTOR