1-5 St Barnabas Mews, London, SW1W 8QB

1-5 St Barnabas Mews, London, SW1W 8QB — City of Westminster Council — Appeal Decision Site visit made on 17 July 2024 by L Reid BSc (Hons) MA MRTPI an Inspector appointed by the Secretary of State Decision date: 24 September 2024 Appeal Ref: APP/X5990/W/23/3335838 1-5 St Barnabas Mews, London SW1W 8QB • 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 Warwick Investment Group against the decision of City of Westminster Council. • The application Ref is 23/01131/FULL. • The development proposed is erection of mansard roof extensions to properties 1-5 St Barnabas Mews to provide additional bedroom space with associated terraces. Decision 1. The appeal is dismissed. Main Issue 2. The main issue is whether the proposal would preserve or enhance the character or appearance of the Belgravia Conservation Area. Reasons 3. As the appeal site is within the Belgravia Conservation Area (the CA), I have had regard to Section 72(1) of the Town and Country Planning (Listed Buildings and Conservation Areas) Act 1990 (the Act) which requires that special attention be paid to the desirability of preserving or enhancing the character or appearance of that area. 4.

1-5 St Barnabas Mews, London, SW1W 8QB — City of Westminster Council — Appeal Decision The significance of the CA, as described in the consultation draft Belgravia Conservation Area Audit 2013 (the draft CA Audit) is primarily derived from the combination of small-scale modest mews, opulent terraces, spacious streets and verdant garden squares. The CA has a strong sense of place and history which is informed in part by the retention of the original architectural features, materials and detailing of some of the buildings. Consequently, the cohesive building groups are important components that contribute to the significance of the CA as a whole. 5. The draft CA Audit identifies that there are a range of mews buildings within the CA which are typically two storeys and are recognised for their small scale in relation to the terraces which they originally served. 6. 1-5 St Barnabas Mews is a terrace block consisting of a row of two-storey properties. It is a modern development and because of its modest scale, proportions and simple detailing it is largely reflective of the original mews-style buildings found in the CA. Although not a historic building, it is an example of the traditional character and style prevalent in the CA.

1-5 St Barnabas Mews, London, SW1W 8QB — City of Westminster Council — Appeal Decision The appeal site therefore makes a positive contribution to the character and appearance of the CA as a whole. https://www.gov.uk/planning-inspectorate

1-5 St Barnabas Mews, London, SW1W 8QB — City of Westminster Council — Appeal Decision The appeal site therefore makes a positive contribution to the character and appearance of the CA as a whole. https://www.gov.uk/planning-inspectorate

1-5 St Barnabas Mews, London, SW1W 8QB — City of Westminster Council — Appeal Decision Appeal Decision APP/X5990/W/23/3335838 7. The proposal seeks to erect mansard roof extensions above each of the properties in the terrace. The roof extensions would effectively be in two blocks to reflect the ‘L’-shape of the terrace and there would be a gap where the blocks meet to create two roof terraces. Three smaller roof terraces would also be created. Glazed balustrades and privacy screening are also proposed. The appeal site is not identified as being unsuitable for a roof extension in the draft CA Audit. However, this represents draft guidance rather than policy. 8. Whilst the roofs of the surrounding buildings are varied, the roof profile typically reflects the architectural style of the buildings. The proposed mansard roofs would increase the height of the terrace and would add a substantial amount of bulk above the first-floor level. The overall scale and bulk of the extensions would fail to respect the existing modest scale of the terrace. 9. Although there is not a consistent roofline across the terrace, there is only a very small height difference where the parapet line changes.

1-5 St Barnabas Mews, London, SW1W 8QB — City of Westminster Council — Appeal Decision When viewed from ground level, even with the lower elements at each end, the difference in the main roofline is not to such an extent that it gives the appearance that the height across the terrace is significantly varied. Instead, there appears to be a broad consistency in height. In contrast, the large flat roof area between the mansards would disrupt the uniformity of the terrace in terms of its height. This inconsistency in the appearance across the terrace would be compounded further as the mansard roof proposed for Unit 4 would have dormer windows in the front elevation, whereas the others would have French doors. 10. As a result of the extensions, the terrace would be no taller than the buildings on the surrounding roads and it would be shorter than the building containing Units 6 – 8. Even though the hierarchy of the buildings would be retained, the terrace would appear top-heavy, which would be a significant change and would cause harm to its appearance. 11.

1-5 St Barnabas Mews, London, SW1W 8QB — City of Westminster Council — Appeal Decision Even if the design of the mansard roof extensions is based on that found in the Council guidance and traditional materials are proposed, including slate, zinc and timber frames, with dormer windows intended to align with the windows below, this would not mitigate the harm caused to the appearance of the terrace, through the loss of its defining characteristics. 12. Any public views of the privacy screens and balustrades would largely be restricted, however, cumulatively these would amount to clutter, given that each property would have one of these features. Despite the set-back, as they would rise above the parapet, this would further accentuate the increase in height of the terrace and the presence of the mansard roof extensions. I am not convinced that this could be resolved by planning condition securing the materiality, as a tall boundary treatment is likely to be required to provide sufficient screening and safety. Even with the use of appropriate materials, this would not overcome the cumulative harm to the existing simple and uncluttered roofscape. 13. Reference is also made to the balustrade present at Unit 6.

1-5 St Barnabas Mews, London, SW1W 8QB — City of Westminster Council — Appeal Decision From ground level, the balustrade itself appears to be low in height and because of this, it is not particularly noticeable. It does not form part of a mansard roof extension and is therefore different to the appeal proposal. I also did not observe any other similar structures. The presence of this feature is therefore of limited weight in my consideration of this appeal. In any event, each proposal must be judged on its individual merits. https://www.gov.uk/planning-inspectorate 2

1-5 St Barnabas Mews, London, SW1W 8QB — City of Westminster Council — Appeal Decision From ground level, the balustrade itself appears to be low in height and because of this, it is not particularly noticeable. It does not form part of a mansard roof extension and is therefore different to the appeal proposal. I also did not observe any other similar structures. The presence of this feature is therefore of limited weight in my consideration of this appeal. In any event, each proposal must be judged on its individual merits. https://www.gov.uk/planning-inspectorate 2

1-5 St Barnabas Mews, London, SW1W 8QB — City of Westminster Council — Appeal Decision Appeal Decision APP/X5990/W/23/3335838 14. The mansard roof extensions would only be seen in some brief public views. However, the harmful effect on the appearance of the terrace through the combination of the roof extensions and the privacy screening and balustrades would be visible from the windows and rear gardens of the surrounding properties. The overall design, height and bulk of the proposal would diminish the positive contribution that the terrace makes to the significance of the CA, causing harm to its character and appearance. 15. The Heritage Appeal Statement1 refers to other historic mews which have mansard style roofs, however, no further details have been provided. Whilst some of the mews shown in Appendix B of the draft CA Audit include roof extensions, these do not appear to form part of the overriding character of the mews in general. 16. Regarding the referenced planning applications for similar developments, as I have not been provided with copies of the approved plans, I cannot ascertain whether these buildings are also of a mews-style and are similar in character and appearance to the appeal site.

1-5 St Barnabas Mews, London, SW1W 8QB — City of Westminster Council — Appeal Decision These developments are also not visible from the appeal site and do not form part of the immediate site context. I cannot be reasonably sure that there are direct parallels between their circumstances and the situation in this appeal case. In the absence of more substantive details, these examples do not weigh in support of the proposal. 17. A more recent development has been approved by the Council for an 18-storey building2 near the appeal site. This does not justify the proposal as it relates to a new building as opposed to an extension of an existing building and differs from the appeal proposal. This development is therefore of limited weight. 18. Although localised in its effect, the harm caused to the CA would be less than substantial. Nevertheless, this attracts considerable weight and importance. In accordance with paragraph 208 of the National Planning Policy Framework, where a development would lead to less than substantial harm to the significance of a designated heritage asset, this harm should be weighed against the public benefits of the proposal. 19.

1-5 St Barnabas Mews, London, SW1W 8QB — City of Westminster Council — Appeal Decision The proposal would provide some social benefits through the enhancement of the existing residential accommodation by providing an additional habitable room within each of the properties. This could allow for the properties to be occupied by more people, including larger families and would optimise the use of the site. The proposal would also provide amenity space for Units 3 and 4 which currently do not benefit from any private amenity space and additional amenity space would be provided for the other properties. However, this is afforded moderate weight given the number of properties that would be enhanced. There would be some economic benefits through the construction phase. However, given the size of the development, these benefits would be modest and short term. The moderate weight I attribute to these public benefits is therefore insufficient to outweigh the less than substantial harm. 20. For the above reasons, I conclude that the proposal would fail to preserve or enhance the character or appearance of the CA. It would conflict with Policies 38, 39 and 40 of the City Plan 2019 – 2040, Adopted April 2021 (the City Plan).

1-5 St Barnabas Mews, London, SW1W 8QB — City of Westminster Council — Appeal Decision These policies, amongst other things, require development to have regard to scale, 1 23 August 2023 2 Council Ref: 20/04366/COOUT https://www.gov.uk/planning-inspectorate 3

1-5 St Barnabas Mews, London, SW1W 8QB — City of Westminster Council — Appeal Decision These policies, amongst other things, require development to have regard to scale, 1 23 August 2023 2 Council Ref: 20/04366/COOUT https://www.gov.uk/planning-inspectorate 3

1-5 St Barnabas Mews, London, SW1W 8QB — City of Westminster Council — Appeal Decision Appeal Decision APP/X5990/W/23/3335838 height, and massing and to preserve or enhance the character and appearance of Westminster’s conservation areas. Other Matters 21. The appeal site is near 20-42 Ebury Bridge Road3 which is Grade II Listed. Mindful of the statutory duty set out at Section 66(1) of the Act, I have had special regard to the desirability of preserving the building or its setting or any features of special architectural or historic interest which it possesses. Given the proximity and physical relationship of the proposal with this designated asset, its setting would be preserved, and the proposal would not detract from it. The Council also did not refuse the application on this matter. Planning Balance and Conclusion 22. Policy 8 of the City Plan, Policy D3 of the London Plan 2021 and the guidance in the Roofs A Guide to Alterations and Extensions on Domestic Buildings set out the support for mansard roof extensions in achieving housing delivery targets and ensuring the optimum viable use of a building is made. However, this must be balanced against the statutory protection that is afforded to conservation areas. 23.

1-5 St Barnabas Mews, London, SW1W 8QB — City of Westminster Council — Appeal Decision The Council identified no harm to be caused to the living conditions of neighbouring occupants. However, compliance with relevant planning policies on this matter would be required for all proposals, so would neither weigh in favour nor against the appeal scheme. 24. The Council Delegated Report indicates that no comments were received from the Belgravia Neighbourhood Forum, Belgravia Residents Association or the Belgravia Society. However, this is not a determinative factor and would not alter my conclusions on the planning merits of the proposal. 25. I have already identified the benefits of the proposal through an assessment of public benefits in undertaking the necessary balancing exercise in relation to the heritage asset. In terms of harm, the proposal would fail to preserve or enhance the character or appearance of the CA, in conflict with the development plan and this would be of greater significance so the appeal scheme would not accord with the development plan, when considered as a whole. 26. The proposal would therefore conflict with the development plan. The material considerations do not indicate that the appeal should be decided other than in accordance with it. 27.

1-5 St Barnabas Mews, London, SW1W 8QB — City of Westminster Council — Appeal Decision For the reasons given above, the appeal should be dismissed.

1-5 St Barnabas Mews, London, SW1W 8QB — City of Westminster Council — L Reid INSPECTOR 3 Historic England List Entry Number: 1066860 https://www.gov.uk/planning-inspectorate 4