BASEMENT, REAR AND SIDE EXTENSIONS & EXTENSION OF ROOF SPACE TO ACCOMMODATE A LARGER KITCHEN, LIVING ROOM AND BEDROOMS TO CREATE A 4 BEDROOM FAMILY HOUSE

Appeal Decision Site visit made on 18 September 2025 by Alexander O’Doherty LLB (Hons) MSc MRTPI an Inspector appointed by the Secretary of State Decision date: 6 October 2025 Appeal Ref: 6000264 18 Trafalgar Grove, Greenwich, London SE10 9TB • 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 Kunle Awosonya against the decision of the Council of the Royal Borough of Greenwich. • The application Ref is 25/0232/HD. • The development proposed is described on the application form as, “BASEMENT, REAR AND SIDE EXTENSIONS & EXTENSION OF ROOF SPACE TO ACCOMMODATE A LARGER KITCHEN, LIVING ROOM AND BEDROOMS TO CREATE A 4 BEDROOM FAMILY HOUSE” . Decision 1. The appeal is dismissed. Preliminary Matters 2. Amended plans were submitted at the appeal stage, regarding 2 alternative designs which primarily relate to the shape of the proposed roof form for 18 Trafalgar Grove (No 18). Although the appellant has referred to the Mast Quay Phase II appeal decision and the potential for the proposed scheme to be altered via planning conditions, the current law on this matter is summarised in the Procedural Guide: Planning appeals – England. The Procedural Guide contains guidance which is directly relevant to this scenario. Therefore, I have followed its principles. 3. The Procedural Guide states that the appeal process should not be used to evolve a scheme and it is important that what is considered by the Inspector at appeal is essentially the same scheme that was considered by the Local Planning Authority and by interested parties at the application stage. The Procedural Guide further states that even potentially beneficial changes may need to be subject to re- consultation, so that interested parties can consider whether that would be the case. 4. In this case, the proposed amendments would alter the design of the proposed development, which is a matter pertaining to the main issue in this appeal, and a matter which several interested parties expressed views on at application stage. Therefore, in the interests of fairness to interested parties, I have considered the same plans that the Council determined the planning application on. To do otherwise would deprive those who should have been consulted on the changes, the opportunity of such consultation. Appeal Decision 6000264 2 5. An additional plan was submitted at the appeal stage1, showing the existing side elevation of No 18. This plan does not alter the nature of the proposed development. I am satisfied that the interests of interested parties would not be prejudiced by this plan being considered. Therefore, I have considered this plan as part of this appeal. Main Issue 6. The main issue is whether the proposed development would preserve or enhance the character or appearance of the East Greenwich Conservation Area and whether the proposed development would protect the Outstanding Universal Value of the Maritime Greenwich World Heritage Site. Reasons Conservation area 7. The appeal site comprises No 18, a modestly-sized 2-storey (plus a basement and including a loft room / study on its 2nd floor) end-of-terrace dwelling situated on a wedge-shaped plot on a cul-de-sac in a residential area. No 18 is the last remaining Victorian-era dwelling present on the east side of Trafalgar Grove, which previously contained a row of Victorian terraced dwellings. No 18 benefits from a good-sized garden. A wall along the southern boundary of the site abuts a sunken railway line. 26 and 27 Trafalgar Grove (Nos 26 & 27), on the western side of Trafalgar Grove, opposite the site, are similar to No 18 in architectural style and detailing. 8. Much of Trafalgar Grove consists of substantially-sized 3 to 5 storey buildings, commonly with basements and mansard roofs. A terrace of properties known as Charville Court, a relatively recent development with mansard roofs, basement levels, and rear outriggers, is set-back from No 18’s principal elevation. The combination of No 18’s siting at the end of the cul-de-sac and its clearly-evident period details mean that it is a distinctive building in the street scene. 9. The site is within the East Greenwich Conservation Area (conservation area). The Planning (Listed Buildings and Conservation Areas) Act 1990 (as amended) provides at s72(1) that with respect to any buildings or other land in a conservation area, special attention shall be paid to the desirability of preserving or enhancing the character or appearance of that area. 10. As explained in the East Greenwich Conservation Area Appraisal (2013), the significance of the conservation area, as a whole, as a designated heritage asset is derived predominantly from its historical development as a low-lying, mainly residential area that occupies a wedge of land between the Royal Naval College, the Maze Hill railway cutting and the Thames. The Inspector’s observation in appeal decision Ref APP/E5330/W/24/3340183 that No 18 and the 2 other terraced properties opposite retain their original architectural detailing and make a positive contribution to the special historic and architectural interest of the conservation area remains the case. 11. The proposed 2-storey side extension element of the proposed development would project over 4 metres beyond No 18’s rear building line. Its bulk would be markedly exacerbated by the proposed crown roof form. Whilst the proposed 1 Existing Side Elevation (Drawing No. 1470-08) Appeal Decision 6000264 3 crown roof would mirror the roof profile of Charville Court, it would bear little stylistic resemblance to No 18’s roof form as existing (which I observed can still be seen from the side and rear of No 18, despite the presence of No 18’s large chimney breast). 12. Moreover, although the proposed 2-storey rear extension element of the proposed development is designed to align with the rearward projection of Charville Court (which presently dominates the rear of No 18), it would nearly double the footprint of No 18 as existing. Similarly, the proposed basement extension of the proposed development would considerably augment No 18’s footprint. 13. Hence, whilst the appellant has highlighted the proposed development’s compliance with certain measurable criteria found within the SPD2, the proposed development when considered as a whole would not be proportionate No 18 as existing. Rather, the proposed works would combine to overly-dominate No 18’s built form. Its presently-modest character, which is indicative of its historic period of construction, would be overwhelmed. As such, the proposed development would not accord with the advice given in paragraph i.21 of the SPD, which provides that, amongst other things, extensions that dominate the existing building in height, bulk or area are not supported. 14. Due to its set-back behind No 18’s principal elevation, the 2-storey side extension element of the proposed development would only be visible in the street scene when standing directly in front of No 18. Even so, this element, and the proposed 2-storey rear extension element of the proposed development would both be visible from the upper-floor windows of properties to the rear of No 18, where the significantly increased bulk and scale of No 18 would be evident. 15. In any event, I am required to assess the effect of the proposed development on the significance of the conservation area when considered as a whole. In this case, the architectural interest of No 18 as a modestly-sized Victorian-era dwelling would be severely compromised. Its notable contribution to the conservation area as the last remaining historic dwelling on the east side of Trafalgar Grove with its original architectural form intact would be undermined. 16. As mentioned above, the proposed 2-storey rear extension would align with the rearward projection of Charville Court. However, much of No 18 would still project considerably forward beyond Charville Court’s principal elevation. Additionally, due to its greatly increased size and scale, No 18 as extended would no longer reflect the spatial characteristics of Nos 26 & 27. As such, the spatial character and the established development pattern of the locality would be adversely affected. 17. It follows that harm to the significance of the conservation area would result. As this harm would be localised, the proposed development would cause less than substantial harm to the significance of the conservation area. The localised nature of the adverse impacts also means that the extent of the harm within this category would be moderate. Nevertheless, any harm to a designated heritage asset is of considerable importance and weight. The National Planning Policy Framework (the Framework) requires such harm to be weighed against the public benefits of the proposed development. These are considered below. 2 Urban Design Guide Supplementary Planning Document (adopted 2023) Appeal Decision 6000264 4 Setting of the World Heritage Site 18. The Framework explains that World Heritage Sites are designated heritage assets and that they have a cultural and / or natural significance which is so exceptional as to transcend national boundaries and to be of common importance for present and future generations. The site is within the buffer zone to the Maritime Greenwich World Heritage Site (WHS). The Planning Practice Guidance advises that a buffer zone forms part of the setting of a World Heritage Site3. 19. The Royal Greenwich Local Plan: Core Strategy with Detailed Policies (adopted 2014) (Local Plan) refers to the Outstanding Universal Value (OUV) of the WHS and mentions that the WHS comprises one of the finest and most dramatically sited architectural and landscape ensembles in the British Isles. This includes the historic centre of the town with the architectural masterpieces and designed landscape of the Old Royal Naval College, National Maritime Museum and extending outside the town centre to include the Royal Park. UNESCO summarises the OUV of the WHS as including, amongst other things, the public and private buildings and the Royal Park at Greenwich which form an exceptional ensemble that bears witness to human artistic and creative endeavour of the highest quality, with a remarkably high degree of authenticity. 20. No 18 is one of a number of historic buildings within the buffer zone which provide a positive contribution towards the quality of the built fabric within the WHS. Specifically, as the last remaining Victorian-era dwelling present on the east side of Trafalgar Grove within the setting of the WHS, No 18 contributes towards the value of the WHS primarily through its historic period of construction and its original architectural detailing and form. 21. The negative effects on No 18’s architectural interest arising via the proposed development, including the overwhelming nature of the proposed development upon No 18’s presently-modest character when seen from the upper-floor windows of nearby properties to the rear, would weaken the contribution that the setting makes to the OUV of the WHS in architectural and historic terms. The ability to appreciate the high quality architecture found within the WHS itself would thereby be compromised. Consequently, the proposed development would have an adverse impact on the OUV of the WHS. 22. As only a single historic building within the buffer zone would be impacted by the proposed development, less than substantial harm would be caused to the significance of the WHS. Due to the localised nature of the adverse impacts, the extent of the harm within this category would be moderate. This harm must be weighed against the public benefits of the proposed development, which are considered below. Public benefits and heritage balance 23. I note the claim that No 18’s habitable rooms do not meet current space standards and that its layout is impractical for modern day living. The proposed development seeks to remedy these concerns, by creating a larger modern family unit with 4 bedrooms and a good-sized rear lightwell / patio. This would assist with the social objective of sustainable development as outlined in the Framework, via No 18 being augmented to such an extent that it would provide a minor contribution 3 Paragraph 18a-033-20190723 Appeal Decision 6000264 5 towards the range of homes in the local area, to meet the needs of present and future generations. The proposed development would likely provide economic benefits by way of providing work for construction professionals. The evidence does not indicate that the scale of these benefits would be significant. 24. The scale of the positive impacts in economic, social, and environmental terms would be constrained by the fact that the proposed development relates to the extension of a single dwelling only. When considered collectively, the public benefits of the proposed development would be modest. Thus, the public benefits of the proposed development merit no more than moderate weight. Taking account of the great weight given to the conservation of each designated heritage asset, the totality of the public benefits would not outweigh the harms identified. 25. I therefore find that the proposed development would neither preserve nor enhance the character or appearance of the conservation area, and that it would not protect the OUV of the WHS. It would conflict with part i. of Policy DH1 of the Local Plan which provides that, amongst other things, to achieve a high quality of design, all developments are expected to provide a positive relationship between the proposed and existing urban context by taking account of architectural, historical and archaeological features and their settings, and with Policy DH3 of the Local Plan which provides that, amongst other things, the Royal Borough will protect and enhance the heritage assets and settings of Royal Greenwich. 26. The proposed development would conflict with part iii. of Policy DH(a) of the Local Plan which provides that, amongst other things, proposals for rear, side and other additions (including basements) should be limited to a scale and design appropriate to the building and locality, and all new roof extensions should be designed to respect the scale and character of the host building. It would conflict with part i) of Policy DH(h) of the Local Plan which provides that, amongst other things, planning permission will only be granted for proposals which pay special attention to preserving or enhancing the character or appearance of the Conservation Area. 27. The proposed development would conflict with Policy DH4 of the Local Plan which provides that, amongst other things, the Royal Borough will protect and enhance the OUV of the inscribed WHS, and that development within it should protect and enhance these Values, and that development within the buffer zone and setting should not adversely impact on those Values, including views to and from the WHS. 28. The proposed development would conflict with part D 11) of Policy D3 of the London Plan (published 2021) which provides that development proposals should respond to the existing character of a place by identifying the special and valued features and characteristics that are unique to the locality and respect, enhance and utilise the heritage assets and architectural features that contribute towards the local character, and with part C of Policy HC1 of the London Plan which provides that, amongst other things, development proposals affecting heritage assets, and their settings, should conserve their significance, by being sympathetic to the assets’ significance and appreciation within their surroundings. 29. The proposed development would conflict with part B of Policy HC2 of London Plan which provides that, amongst other things, development proposals in World Heritage Sites and their settings, including any buffer zones, should conserve, Appeal Decision 6000264 6 promote and enhance their OUV, including the authenticity, integrity and significance of their attributes, and support their management and protection, and that in particular, they should not compromise the ability to appreciate their OUV, or the authenticity and integrity of their attributes. 30. The proposed development would also conflict with section 16 of the Framework, which seeks to conserve and enhance the historic environment. Other Matters 31. The conduct of the Council during the processing of the planning application is not a matter that I can assess in the context of a planning appeal. 32. Paragraph 125 e) of the Framework provides that, amongst other things, planning decisions should support opportunities to use the airspace above existing residential and commercial premises for new homes, including allowing upward extensions. As the proposed development would not extend No 18 upwards by way of a mansard roof or an additional storey, this is a neutral matter, which does not weigh in favour of the proposed development. Other Considerations and Planning Balance 33. The various public benefits of the proposed development have been summarised on the main issue above, with no more than moderate weight having been attributed. 34. The proposed development would benefit the current and future occupiers of No 18 by way of providing enlarged living accommodation suitable for contemporary living, including improved lighting to the basement. However, it has not been demonstrated that a less harmful scheme could not achieve the same aims, and as these would mainly comprise private benefits, these benefits merit little weight in favour of the proposed development. 35. The proposed development would make an effective use of land in an accessible location, which is supported by the Framework. As the proposed development relates to the enlargement of a single dwelling only, the benefits accruing to the local area in this respect would be minimal. This matter attracts little weight in favour of the proposed development. 36. The proposed development would harm the significance of the conservation area and it would not protect the OUV of the WHS. Planning law requires that each individual incidence of harm to a designated heritage asset must be given considerable importance and weight. As such, very great weight is ascribed to the totality of the adverse impacts identified. 37. Taking all of the above into account, whilst the proposed development has merit, the totality of its benefits would not be sufficient to outweigh the harms identified on the main issue above. The relevant material considerations do not indicate that the appeal should be decided otherwise than in accordance with the development plan. Appeal Decision 6000264 7 Conclusion 38. For the reasons given above, having considered the development plan as a whole, the approach in the Framework, and all other relevant material considerations, I conclude that the appeal should be dismissed. Alexander O’Doherty INSPECTOR