40 Thurloe Square, LONDON, SW7 2SR

40 Thurloe Square, LONDON, SW7 2SR — Royal Borough of Kensington and Chelsea — by A Tucker BA (Hons) IHBC an Inspector appointed by the Secretary of State Decision date: 21 June 2024

40 Thurloe Square, LONDON, SW7 2SR — Royal Borough of Kensington and Chelsea — 40 Thurloe Square, London SW7 2SR • 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 Lady Angest against the decision of The Council of The Royal Borough of Kensington and Chelsea. • The application Ref is PP/23/06682. • The development proposed is creation of a single storey ground floor and lower ground floor extension with internal and external alterations.

40 Thurloe Square, LONDON, SW7 2SR — Royal Borough of Kensington and Chelsea — 40 Thurloe Square, London SW7 2SR • The appeal is made under section 20 of the Planning (Listed Buildings and Conservation Areas) Act 1990 (as amended) against a refusal to grant listed building consent. • The appeal is made by Lady Angest against the decision of The Council of The Royal Borough of Kensington and Chelsea. • The application Ref is LB/23/06683. • The works proposed are creation of a single storey ground floor and lower ground floor extension with internal and external alterations.

40 Thurloe Square, LONDON, SW7 2SR — Royal Borough of Kensington and Chelsea — prejudiced by my doing so. https://www.gov.uk/planning-inspectorate

40 Thurloe Square, LONDON, SW7 2SR — Royal Borough of Kensington and Chelsea — prejudiced by my doing so. https://www.gov.uk/planning-inspectorate Appeal Decisions APP/K5600/W/24/3340439, APP/K5600/Y/24/3340438 Main Issue 5. The main issue for both appeals is the effect upon the significance of the grade II listed building known as 34-44 Thurloe Square1. Reasons 6. Sections 16(2) and 66(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990 (LBCA) require the decision maker to have special regard to the desirability of preserving a listed building or its setting or any features of special architectural or historic interest which it possesses. 7. The appeal building is a house that stands within a terrace of matching dwellings that are covered by a single listing designation. The terrace dates from 1839-43. Its significance primarily lies in its uniform front façade, which is defined by its formal composition and rhythm, and its position fronting a square. Each dwelling is marked by a projecting porch. The ground floor has a stucco finish, and subsequent storeys diminish in scale as they rise from street level. 8. The historic plan form of the dwellings that make up the terrace are also of significance as are remaining elements of the rear façade and the service floors.

40 Thurloe Square, LONDON, SW7 2SR — Royal Borough of Kensington and Chelsea — prejudiced by my doing so. Although these secondary elements are more altered and without the same architectural refinement as the front elevation, they do give it authenticity. They are not the primary reasons that the terrace would have been listed; yet they are of some significance as they aid our appreciation of the hierarchy of spaces as they would have been built originally and illustrate how each dwelling would have functioned and been occupied. 9. The appeal building largely retains its original footprint, which includes a modest protrusion that extends into the small rear yard and served originally as a scullery. Historic England guidance recognises that early service or closet wings are now unusual and important where they survive2. Behind the scullery a full width room was the original kitchen and an open lightwell behind that provided daylight and ventilation to the inner room. This unusual layout is depicted on historic plans and maps and would appear to be original to the terrace. Above this the original half width closet wing survives and a conservatory has been added alongside with a gap for the lightwell retained between the conservatory and the hallway behind.

40 Thurloe Square, LONDON, SW7 2SR — Royal Borough of Kensington and Chelsea — prejudiced by my doing so. The original layout to the ground floors is therefore clearly discernible at the appeal building, and this contributes to the significance of the terrace. 10. The proposal would see the loss of the original scullery and steps that provide access up from the lower ground floor to the yard. These would be replaced with an extension to the building that would occupy the entire area of the original yard. In doing so the relationship between the lower ground floor and the yard would be lost and the historic floor plan at this level considerably altered. The Historic England guidance referred to above states that it is important to ensure an appropriate relationship is maintained between the main house, rear extensions and the original extent of the yard or garden. This would be entirely lost at lower ground floor level by the proposal. 1 List Entry Number: 1226951 2 Historic England: Conserving Georgian and Victorian terraced housing https://www.gov.uk/planning-inspectorate 2

40 Thurloe Square, LONDON, SW7 2SR — Royal Borough of Kensington and Chelsea — prejudiced by my doing so. Appeal Decisions APP/K5600/W/24/3340439, APP/K5600/Y/24/3340438 11. The existing decking already encloses this area to an extent. However, this reads as a garden surface. It is laid in a typical fashion with gaps, which give the sense from above that the surface is raised. It would be possible to reinstate the use of the yard by removing the timber and cutting the steels off at ground level. 12. From below, although the space is currently largely unusable, it can still be understood as the former yard. In contrast, the proposal would see the yard level effectively raised to form the roof of the extension. An area of flat glazing would be inserted into the new yard level to provide daylight to the room below. It would be possible to look down through this glass into the room. However, it is not clear how this would be suggestive of the former yard given that the levels would be different, and the space would be furnished and fitted out as a living room. 13. For these reasons I find that this element of the proposal would lessen our understanding of the way the house originally functioned and incur the loss of some original fabric.

40 Thurloe Square, LONDON, SW7 2SR — Royal Borough of Kensington and Chelsea — prejudiced by my doing so. Given the simple construction of this area of the building and the modest scale of the loss relative to the whole terrace, the impact on the significance of the listed building would however be no more than moderate. 14. The original kitchen would be reduced in size. Although inserted studwork could be removed in the future, reducing the scale of the room and severing it from the former opening to the scullery would increase the level of harm. Furthermore, harm would also arise from moving the original rear window. Although this would be lessened modestly by re-using it elsewhere in the building, such an intervention would muddle our understanding of the building and would not accord with the established conservation principles of maintaining historic authenticity and legibility. 15. Additional harm would arise from the rebuilding of the wall between the lightwell and this room. The re-alignment would be modest and would be unlikely to have a meaningful impact on light levels that could reach the surrounding rooms; yet it would see an element of original structure and part of the original layout of the terrace – which is rather unique and retained at this property – eroded. 16.

40 Thurloe Square, LONDON, SW7 2SR — Royal Borough of Kensington and Chelsea — prejudiced by my doing so. The proposal would see the lightwell enclosed. Currently it is open, although the first floor has been extended out over it. From the lobby at the base of the main stair there is a view out to the sky through the existing French doors. From this perspective the existing conservatory has a detached appearance, and the original arrangement can be understood, whereby an unobstructed view would have been possible to the rear from a principal element of the building’s interior. Enclosing the lightwell would not only lessen our appreciation of this part of the building as an external area, but it would also result in a subtle yet significant change to the spatial arrangement for this principal internal space by turning it into an inner room without an external outlook at the rear. 17. The base of the current light well is not a pleasant space. However, daylight is currently significantly reduced by the grill covering and the items that stand on the grill. Redecorating it and altering the grill arrangement as well as removing the boiler cupboard would achieve some improvement without moving the wall or inserting French doors. https://www.gov.uk/planning-inspectorate 3

40 Thurloe Square, LONDON, SW7 2SR — Royal Borough of Kensington and Chelsea — prejudiced by my doing so. Appeal Decisions APP/K5600/W/24/3340439, APP/K5600/Y/24/3340438 18. I am satisfied that extending at the rear of the closet wing at upper ground floor level need not be harmful as a matter of principle. Several similar extensions exist along the terrace and such an addition could be formed in an additive manner that retains the historic plan form and appearance of the original closet wing. Externally the proposed extension would be difficult to identify, as the materials, coping and balustrade would be contiguous with the existing. Internally, the floor plan would be largely retained, although it is unclear why the existing rear opening would be widened. This is unfortunate as retaining the width would allow the low arch to also be retained. 19. The adjacent infill extension would be set back considerably from the extended closet wing, and would thus successfully read as an additional element. Its outward face would be well proportioned. It would be an improvement to the existing conservatory, which has an odd glazing pattern to its upper openings.

40 Thurloe Square, LONDON, SW7 2SR — Royal Borough of Kensington and Chelsea — prejudiced by my doing so. The proposed cornice detail would be deep and much more substantial than the existing, but this need not be a problem given that it would be set back and down from the adjacent wing. The projecting plinth would most likely read as a raised bed rather than part of the structure once planted and would therefore also not cause harm. Internally the identity of the original closet wing and the adjacent infill extension would be sufficiently retained by a downstand detail, details of which could be secured by an appropriately worded condition if the appeals are allowed. 20. Taken together the interventions would result in a considerable level of harm to the building that would incur the loss of original fabric and plan form, and erode the significance of the listed building. In terms of the National Planning Policy Framework (Framework) the harms would be less than substantial but would nevertheless be of considerable importance and weight. Paragraph 208 of the Framework establishes that any harm should be weighed against the public benefits of the proposal. 21. Removing the small boiler room from the lightwell has the potential to reinstate this original arrangement and thus better reveal the significance of the asset.

40 Thurloe Square, LONDON, SW7 2SR — Royal Borough of Kensington and Chelsea — prejudiced by my doing so. The benefit of this is however offset by the proposed rebuilding of the wall between the lightwell and the existing rear room. The result would therefore be a modified and inauthentic version of the original lightwell. As such, I give very little weight to the benefit of removing the boiler room. 22. The replacement of the upper ground floor WC window is mistakenly referred to as a benefit, as this window is a sash window that may be original and should be retained. 23. The replacement of inappropriate windows at the rear would benefit the appearance of the building, as would the replacement conservatory extension. These are heritage related public benefits that should attract reasonable weight. 24. The replacement of the existing balustrade at the rear would only be a modest benefit as the existing balustrade is of a simple design that is not obviously harmful. The same can be said for the restoration of original ceiling mouldings at upper ground floor level; whilst the difference is identified in the heritage appraisal, both appear appropriate, and it is not clear which one would be replaced. Therefore, these benefits should attract little weight. https://www.gov.uk/planning-inspectorate 4

40 Thurloe Square, LONDON, SW7 2SR — Royal Borough of Kensington and Chelsea — prejudiced by my doing so. Appeal Decisions APP/K5600/W/24/3340439, APP/K5600/Y/24/3340438 25. The reinstatement of the doorway at first floor level would be a modest benefit given the small scale of this element of the scheme. The same can be said of the replacement of an internal door at second floor level, and the removal of built in joinery on the third floor. 26. Together these public benefits carry reasonable weight. I need to consider this in the context of paragraph 205 of the Framework which states that great weight should be given to the conservation of heritage assets. Taking these matters together, the public benefits of the proposal would not be sufficient to outweigh the harm. 27. In summary, the proposal would fail to meet the requirements of the LBCA as it would harm the special interest of the listed building. It would also fail to accord with Policy CL4 of the Local Plan 2019 and CD4 of the NLPR, which together seek to ensure that proposals protect heritage significance. Other Matters 28. The appeal building stands within the Thurloe and Smith Charity Conservation Area (CA).

40 Thurloe Square, LONDON, SW7 2SR — Royal Borough of Kensington and Chelsea — prejudiced by my doing so. Section 72 of the LBCA requires special attention to be paid to the desirability of preserving or enhancing the character or appearance of a conservation area. The Council is satisfied that the proposal would preserve the character, appearance and setting of the CA. Based on the evidence before me and my observations on site I see no reason to take a contrary view. Conclusion 29. For the reasons given above the appeals should be dismissed.

40 Thurloe Square, LONDON, SW7 2SR — Royal Borough of Kensington and Chelsea — A Tucker INSPECTOR https://www.gov.uk/planning-inspectorate 5

40 Thurloe Square, LONDON, SW7 2SR — Royal Borough of Kensington and Chelsea — A Tucker INSPECTOR https://www.gov.uk/planning-inspectorate 5 Appeal Decisions APP/K5600/W/24/3340439, APP/K5600/Y/24/3340438 Appearances FOR THE APPELLANT: Dorian A. T. A. Crone BA BArch DipTP RIBA MRTPI IHBC Heritage Consultant Meilsa Thomas BA PGDL LPC MSc IHBC Heritage Consultant Alex Tart RIBA ARB Architect Bryan Staff Planning Consultant FOR THE LOCAL PLANNING AUTHORITY: Emma Gore BA (Hons) MSc (Spatial Planning) Senior Planning Officer, Lead Officer Pheobe Graham BA (Hons) MSc Senior Design and Heritage Officer, Lead Conservation Officer Russell Frew BSc MSc Senior Design and Heritage Officer, Assistant Conservation Officer Documents submitted during the hearing A copy of a representation from South Kensington Estates dated 9 April 2024 was submitted during the hearing. https://www.gov.uk/planning-inspectorate 6