1 Halsey Street, LONDON, SW3 2QH

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — by L J O'Brien BA (Hons) MA MRTPI an Inspector appointed by the Secretary of State Decision date: 06 May 2026

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — 1 Halsey Street, LONDON, SW3 2QH • 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 Icon Architects Ltd. against the decision of Royal Borough of Kensington and Chelsea. • The application Ref is PP/25/03289. • The development proposed is Ground and first floor closet wing extension to increase depth of the existing closet wing; removal of non-original door and replacement with sash window; removal of railings on unofficial terrace to rear; removal and relocation of original sash window in horizontal extension; and installation air conditioning unit to internal joinery in rear reception room; and reconfiguration of ground floor primary reception rooms to return them to original proportion with original features reinstated.

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — 1 Halsey Street, LONDON, SW3 2QH • 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 Icon Architects Ltd. against the decision of Royal Borough of Kensington and Chelsea. • The application Ref is LB/25/03290. • The works proposed are Ground and first floor closet wing extension to increase depth of the existing closet wing; removal of non-original door and replacement with sash window; removal of railings on unofficial terrace to rear; removal and relocation of original sash window in horizontal extension; and installation air conditioning unit to internal joinery in rear reception room; and reconfiguration of ground floor primary reception rooms to return them to original proportion with original features reinstated.

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — original application forms. https://www.gov.uk/planning-inspectorate Appeal Decisions APP/K5600/W/25/3374319, APP/K5600/Y/25/3374318 4. Both appeals relate to 1 Halsey Street which forms part of a Grade II listed building1, 1-23 Halsey Street, situated within the Chelsea Conservation Area (CA). The descriptions of development/works are the same for both proposals and the issues within the appeals are similar. As such I have dealt with them within the same Decision Letter. I have, however, set out two separate formal Decisions in the interests of clarity. 5.

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — original application forms. Appeal Decisions APP/K5600/W/25/3374319, APP/K5600/Y/25/3374318 4. Both appeals relate to 1 Halsey Street which forms part of a Grade II listed building1, 1-23 Halsey Street, situated within the Chelsea Conservation Area (CA). The descriptions of development/works are the same for both proposals and the issues within the appeals are similar. As such I have dealt with them within the same Decision Letter. I have, however, set out two separate formal Decisions in the interests of clarity. 5.

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — original application forms. In May 2025 planning permission2 and listed building consent3 were granted for “refurbishment of property comprising installation of AC units in principal rooms; like for like replacement of non-original windows with slimline double glazed units; waterproofing to lower ground floor; internal alterations including reinstatement of period features; underfloor heating; reinstatement of original two room plan form in original building; non-original rear extension to be demolished and rebuilt; alterations to flat roof including introduction of rooflights; alterations to rear garden and new garden access door; lightweight glazing roof installed to connect new extension to existing listed building; replacement of garden stairs; extension to utility room under front steps; roof treatment; replacement of front lightwell stairs; repair/replacement of front steps; repairs to front railings; removal of blocked up fireplace surround to exposed chimney breast in rear room; rebuilding of existing roof mansard, with front and back dormer windows; and new additional storey added to closet wing”. At the time of my site visit works had commenced. 6.

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — original application forms. As required by sections 16(2), 66(1) and 72(1) of the Planning (Listed Buildings and Conservation Areas) Act 1990 (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; and paid special attention to the desirability of preserving or enhancing the character or appearance of the conservation area. Main Issue 7. The main issue in these appeals is whether the proposals would preserve the listed building or any features of special architectural or historic interest which it possesses and, linked to that, whether the proposal would preserve or enhance the character or appearance of the conservation area. Reasons Special interest and significance 8. No 1 Halsey Street is a town house with accommodation set across a lower ground floor, an upper ground floor, a first floor, a second floor and at third floor level within a mansard roof. The property is at the end of a terrace of similar houses which together (Nos 1 - 23) form a listed building which dates from the mid 19th Century. A very similar terrace, Nos 24 – 47 Halsey Street is situated opposite. 9.

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — original application forms. The front elevation of the property is constructed of stock brick with banded render to the ground floor and stucco facing on the upper floors to the parapet. The fenestration is consistent across the properties which form part of the listed building and attractive iron railings are a further consistent feature. 1 National Heritage List for England Entry Number: 203804 2 PP/25/01234 3 LB/25/01235 https://www.gov.uk/planning-inspectorate 2

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — original application forms. The front elevation of the property is constructed of stock brick with banded render to the ground floor and stucco facing on the upper floors to the parapet. The fenestration is consistent across the properties which form part of the listed building and attractive iron railings are a further consistent feature. 1 National Heritage List for England Entry Number: 203804 2 PP/25/01234 3 LB/25/01235 https://www.gov.uk/planning-inspectorate 2

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — original application forms. Appeal Decisions APP/K5600/W/25/3374319, APP/K5600/Y/25/3374318 10. The architectural detailing of the rear elevation is generally more simple and is constructed of stock brick with detailed brick courses around the windows. There is a rear closet wing which the evidence before me indicates is apparent in 19th Century maps. The closet wing is reflected at other properties in the vicinity. The well-proportioned features create a strong sense of cohesion. 11. Due to its location at the end of the terrace the side elevation of the building and the closet wing projection is prominent in views from the street and its simple, stepped profile adds to the appreciation of the building and its proportions. 12. In my view, in its simplicity, the rear elevation of the building has a reserved dignity which is attractive and contributes to the significance of the asset. 13. The significance of the building as a heritage asset insofar as it relates to these appeals derives, in part, from the buildings place as a component of the development of this part of Chelsea and the architectural interest of the building as an attractive dwelling from the 19th Century.

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — original application forms. Significance is also derived from the surviving historic fabric and plan form, especially the closet wing which provides evidence of the typical, form, function and room layout of town houses of this type and status in the area. The building also has group value with the other nearby terraces, particularly Nos 24 – 47 opposite. 14. The appeal site is also located within the Chelsea Conservation Area (CA). The Chelsea Conservation Area Appraisal, January 2016 (CAA) states that the CA comprises groups of generally modest residential terraces from which the charm of the CA is derived. As an example of a property within one such residential terrace, the appeal property contributes positively to the significance of the CA. Effects of the proposals 15. Amongst other aspects which I will return to later, the proposals involve extending the closet wing at upper ground and first floor level; increasing its depth by around 1.3 metres in order to provide additional accommodation. 16. The extended closet wing would occupy a visually prominent position at a raised level and would span two floors of the building. The deeper extended closet wing would appear as a notable projection from the rear elevation of the building.

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — original application forms. The ratio of projection to void would be harmfully altered and the proposals would undermine the modest proportions of the rear closet wing. The proposals would disrupt the understated and restrained character of the rear elevation. The proposed closet wing would no longer be reflective of the typical form, function and layout of town houses of this type and its historic interest would be diminished. 17. Due to the prominent position of the appeal property at the end of the terrace, the extended closet wing would be highly visible from nearby streets and the hierarchy and composition of the side profile of the building would be eroded. 18. I note that the increased depth would be stepped in by one brick with the aim of not disrupting the side elevation and providing subtle legibility of the extension. This would indeed assist in allowing the evolution of the building to be read. However, the extended closet wing would, nevertheless, appear as a larger addition which would fail to respect the constrained proportions and articulation of the rear elevation and the small step-in would not mitigate the harm I have set out above. https://www.gov.uk/planning-inspectorate 3

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — original application forms. Appeal Decisions APP/K5600/W/25/3374319, APP/K5600/Y/25/3374318 19. I accept that other properties in the area have altered their rear closet wings, a matter which I will return to later. However, though they are not identical, the neighbouring properties in the immediate vicinity of the appeal site have similar closet wings of a similar depth. Thus, the properties at the end of the listed terrace itself which are terminated by the appeal property have a sense of cohesion and regularity. The proposals would distort the rhythm of the rear of the buildings and would cause harm to the composition of this element of the terrace as a whole. 20. The evidence before me indicates that the extension would be constructed in reclaimed bricks following the careful dismantling of the rear wall of the existing closet wing and supplemented by additional matching bricks reclaimed elsewhere. The bonds would be matching with matching pointing and mortar. Other details such as the coping would match those found on adjacent buildings. Nevertheless, the closet wing would no longer represent an authentic piece of the historic fabric of the building and the patina of age would be lost.

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — original application forms. It is also probable that bricks would be lost or damaged during the demolition and construction processes. As such, in my view, in addition to the visual harm which I have identified, the proposals would result in the loss of historic fabric. 21. Furthermore, as set out above, in May 2025 planning permission and listed building consent were granted for a number of alterations to the property. The permitted schemes include adding an additional storey, at second floor level, to the closet wing. Were both schemes to proceed, the resultant closet wing would extend upwards and outwards and would no longer appear as a discreet and subservient element of the rear of the building but would rather be a visually dominant feature which would compete with the host dwelling. 22. In addition to the aforementioned elements of the proposals a number of other developments/works are proposed. This includes a number of alterations to the fenestration. Two ground floor single glazed replacement sash windows would be replaced with slim double-glazed units of a more sympathetic design and appearance.

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — original application forms. The first-floor window would be removed and re-instated in a corresponding position within the proposed new wall with the re-used stone cill and reformed brick segmental shall-arched head. At upper ground floor level the double glazed door which provides access onto the flat roof below would be removed and replaced with a 6 over 6 pane double glazed sash window which would better match others within the building. 23. The scheme also includes the removal of modern railings from the rear, and internal works comprising the installation of an air-conditioning unit within bespoke joinery to the rear reception room and the reconfiguration of the upper ground floor reception rooms to reinstate their original proportions with original features also reinstated. This would include replacing modern internal doors with traditional doors, repairing and restoring the staircase, removing the suspended ceiling and reinstating a ceiling rose, reinstalling a traditional fireplace, partially rebuilding the dividing wall and relocating this and careful cleaning and restoration of the external brickwork to enhance and preserve the original character and appearance of the building.

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — original application forms. Additional insulation on the inside of the gable walls and under-floor heating is also proposed. 24. The Council have not raised any concerns regarding these additional elements of the proposals and I concur with their view that these aspects of the https://www.gov.uk/planning-inspectorate 4

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — original application forms. Additional insulation on the inside of the gable walls and under-floor heating is also proposed. 24. The Council have not raised any concerns regarding these additional elements of the proposals and I concur with their view that these aspects of the https://www.gov.uk/planning-inspectorate 4

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — original application forms. Appeal Decisions APP/K5600/W/25/3374319, APP/K5600/Y/25/3374318 development/works would have either a neutral impact on, or be of benefit to, the appeal property. I will further assess the potential benefits of the scheme below. 25. I accept that the property has been altered over time and that these further changes could be considered as part of the building’s evolution. I also acknowledge that there can be a place for well managed changes to be made to historic buildings. However, in this instance, the proposals would be such that they would cause undue harm to the host building and the listed building as a whole. 26. I assent that other closet wings within the area, and indeed within the terrace of which the appeal property is part, have been altered over time. Despite these changes, as explored above, the properties closest to the appeal building remain similar to the appeal property. In any event, each case must be determined on its own merits based on the specific circumstances at each site. These circumstances will rarely, if ever, be identical. 27. Of particular relevance to these appeals are schemes along Halsey Street to which the appellant has drawn my attention.

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — original application forms. However, the evidence before me indicates that these proposals were permitted some time ago. Table 2 within the Appellant’s Statement of Case, indicates that the schemes range from 2012 to 2023. All, therefore, pre-date the current planning policy context. Furthermore, I am not aware of the specific details regarding the previous condition of these properties, the immediate context provided by close neighbours, or the degree, if any, of historic fabric which would have been lost. In any event, the existence of other examples is not, in and of itself, a sufficient reason to justify the grant of planning permission or listed building consent. Particularly in circumstances where harm has been identified. 28. Moreover, to my mind, the previous changes to the designated heritage asset, when considering the appeal property in isolation and also in the context of the listed terrace as a whole, further cement the vital importance of any remaining historic fabric. Considered cumulatively the previous alterations increase the sensitivity of the building to further change, particularly change of the magnitude proposed in this instance.

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — original application forms. Were these proposals to go ahead, the changes to the building would be such that the historic significance of the asset would be substantially weakened. 29. The Council have stated that though there would be some impact to the CA as a result of the proposals, this would not be to such an extent so as to cause harm. This is due to the particular circumstances of the site and the wider planning context. Though I have found harm to the heritage asset itself, based on the evidence before me I have not been provided with any compelling evidence to lead me to conclude otherwise in respect of the broader effect on the CA as a whole. As such, overall, I consider that the proposals would preserve the character or appearance of the CA. 30. Nevertheless, for the reasons set out above, alone and in combination with the previously approved development/works, the proposals would unacceptably diminish the architectural and historic interest of the listed building thereby undermining the significance of the designated heritage asset. The proposal would therefore fail to preserve the special architectural and historic interest of the Grade II listed building. https://www.gov.uk/planning-inspectorate 5

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — original application forms. Appeal Decisions APP/K5600/W/25/3374319, APP/K5600/Y/25/3374318 31. In finding harm to the significance of a designated heritage asset the National Planning Policy Framework (The Framework) requires the category of harm to be identified. The Planning Practice Guidance (PPG) expands upon this by requiring the extent of harm within that category to be clearly articulated. In this instance, given the limited extent and nature of the proposed development and works, the harm to the significance of the designated heritage asset would be at the lower end of less than substantial. Notwithstanding this, the identified harm is of considerable importance and weight. 32. The approach set out in the Framework is that where a proposal would lead to less than substantial harm to the significance of a designated heritage asset, as in this case, that harm should be weighed against the public benefits of the proposal including, where appropriate, securing its optimum viable use. Public benefits and heritage balance 33. It is not unreasonable to conclude that the proposals would lead to economic, social and environmental benefits. Amongst other things, these would stem from engaging local professionals, trades and suppliers.

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — original application forms. The proposals would further enhance the property as a family home. Notwithstanding this, there is no substantive evidence before me which demonstrates that the proposed development and works are necessary to secure the ongoing use of the heritage asset in this way. 34. I accept that the scheme has a number of other potential benefits; particularly with regard to elements of the building which would be enhanced to better reveal their significance. The enhancements are broadly set out in the preceding paragraphs regarding the effects of the proposals but include fenestration improvements, the reinstatement of historic features and the cleaning of the exterior brickwork amongst other things. However, in my view, such improvements could be made through alternative schemes which would not cause the degree of harm I have outlined above. 35. Indeed, a number of the benefits, though not all, would also be achieved by the implementation of the previously approved scheme and are not, therefore, a direct consequence of the current proposals before me.

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — original application forms. There is no substantive evidence before me which would lead me to conclude that the benefits which are also associated with the previous scheme would not be achieved were the proposals before me not to go ahead. 36. Whilst a number of the benefits outlined above would be private, they would also be such that they could be considered to be of broader benefit to the public. Overall, the associated benefits are limited by the questions regarding the direct reliance of some of the enhancements on the appeal proposals and the small scale of the proposals and must be considered in that context. 37. Conversely, on the other side of the balance, I have found that the proposals would fail to preserve the special architectural and historic interest of the Grade II listed building. The Framework indicates that great weight should be given to the conservation of such heritage assets. Consequently, the public benefits of the scheme do not outweigh the harm identified. 38. The proposal would, therefore, conflict with the statutory presumptions of s.16(2) and s.66(1) of the Act. The proposal would also conflict with Policies Local Plan https://www.gov.uk/planning-inspectorate 6

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — original application forms. Appeal Decisions APP/K5600/W/25/3374319, APP/K5600/Y/25/3374318 Policies CD3 and CD5 of the Kensington and Chelsea New Local Plan Review, July 2024 (LP). Taken together and amongst other things these policies state that applications for development which affect a designated heritage asset will be permitted if they preserve or enhance the significance of the asset and that any harm to the significance of an asset will require clear and convincing justification. In this instance no such justification is present. 39. Furthermore, the proposal would fail to conform with the Framework’s expectation that great weight should be given to the conservation of heritage assets which are considered an irreplaceable resource, and should be conserved in a manner appropriate to their significance, so that they can be enjoyed for their contribution to the quality of life of existing and future generations. Conclusion 40. For the reasons set out above the appeals are dismissed.

1 Halsey Street, LONDON, SW3 2QH — Royal Borough of Kensington and Chelsea — L J O'Brien INSPECTOR https://www.gov.uk/planning-inspectorate 7