3 Keystone Crescent, LONDON, N1 9DS

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — by A Tucker BA (Hons) IHBC an Inspector appointed by the Secretary of State Decision date: 6th November 2025

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — 3 Keystone Crescent, Islington, London N1 9DS • 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 Sir Cameron Mackintosh against the decision of the Council of the London Borough of Islington. • The application Ref is P2024/3477/FUL. • The development proposed is refurbishment of existing house, to create 2-3 bedroomed home. Single storey rear extension at lower-ground floor level. Small rear dormer extension at second floor level.

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — 3 Keystone Crescent, Islington, London N1 9DS • 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 Sir Cameron Mackintosh against the decision of the Council of the London Borough of Islington. • The application Ref is P2024/3478/LBC. • The works proposed are refurbishment of existing house, to create 2-3 bedroomed home. Single storey rear extension at lower-ground floor level. Small rear dormer extension at second floor level.

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — 4 Keystone Crescent, Islington, London N1 9DS • 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 Sir Cameron Mackintosh against the decision of the Council of the London Borough of Islington. • The application Ref is P2024/3480/FUL. • The development proposed is refurbishment of existing house, to create a 2-3 bedroomed home. Single storey rear extension at lower-ground floor level. Small rear dormer extension at second floor level.

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — 4 Keystone Crescent, Islington, London N1 9DS • 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 Sir Cameron Mackintosh against the decision of the Council of the London Borough of Islington. • The application Ref is P2024/3482/LBC. • The works proposed are refurbishment of existing house, to create a 2-3 bedroomed home. Single storey rear extension at lower-ground floor level. Small rear dormer extension at second floor level. https://www.gov.uk/planning-inspectorate

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — 4 Keystone Crescent, Islington, London N1 9DS • 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 Sir Cameron Mackintosh against the decision of the Council of the London Borough of Islington. • The application Ref is P2024/3482/LBC. • The works proposed are refurbishment of existing house, to create a 2-3 bedroomed home. Single storey rear extension at lower-ground floor level. Small rear dormer extension at second floor level. https://www.gov.uk/planning-inspectorate

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — 4 Keystone Crescent, Islington, London N1 9DS Appeal Decisions APP/V5570/W/25/3366692, APP/V5570/Y/25/3366693, APP/V5570/W/25/3366695, and APP/V5570/Y/25/3366696 Decision – Appeal A 1. The appeal is allowed, and planning permission is granted for refurbishment of existing house, to create 2-3 bedroomed home. Single storey rear extension at lower-ground floor level. Small rear dormer extension at second floor level at 3 Keystone Crescent, Islington, London N1 9DS in accordance with the terms of the application, Ref P2024/3477/FUL, subject to the conditions in the attached schedule. Decision – Appeal B 2. The appeal is allowed, and listed building consent is granted for refurbishment of existing house, to create 2-3 bedroomed home. Single storey rear extension at lower-ground floor level. Small rear dormer extension at second floor level at 3 Keystone Crescent, Islington, London N1 9DS in accordance with the terms of the application, Ref P2024/3478/LBC, and the plans submitted with it, subject to the conditions in the attached schedule. Decision – Appeal C 3. The appeal is allowed, and planning permission is granted for refurbishment of existing house, to create a 2-3 bedroomed home. Single storey rear extension at lower-ground floor level.

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — 4 Keystone Crescent, Islington, London N1 9DS Small rear dormer extension at second floor level at 4 Keystone Crescent, Islington, London N1 9DS in accordance with the terms of the application, Ref P2024/3480/FUL, subject to the conditions in the attached schedule. Decision – Appeal D 4. The appeal is allowed and listed building consent is granted for refurbishment of existing house, to create a 2-3 bedroomed home. Single storey rear extension at lower-ground floor level. Small rear dormer extension at second floor level at 4 Keystone Crescent, Islington, London N1 9DS in accordance with the terms of the application Ref P2024/3482/LBC and the plans submitted with it subject to the conditions in the attached schedule. Preliminary Matters 5. Appeals A and B are for No. 3 Keystone Crescent and relate to the same scheme under different legislation. Appeals C and D are for No. 4 Keystone Crescent and relate to the same scheme under different legislation. Although the buildings are slightly different the proposals are very similar. Accordingly, I have dealt with all the appeals together in my reasoning. Main Issue 6.

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — 4 Keystone Crescent, Islington, London N1 9DS The main issue for all the appeals is the effect of the proposals upon the significance of the grade II listed building known as Numbers 1 to 18 (Consecutive) and attached railings, Keystone Crescent1, and whether they would preserve or enhance the character or appearance of the Keystone Crescent Conservation Area (CA). 1 List Entry Number: 1366067 https://www.gov.uk/planning-inspectorate 2

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — 4 Keystone Crescent, Islington, London N1 9DS The main issue for all the appeals is the effect of the proposals upon the significance of the grade II listed building known as Numbers 1 to 18 (Consecutive) and attached railings, Keystone Crescent1, and whether they would preserve or enhance the character or appearance of the Keystone Crescent Conservation Area (CA). 1 List Entry Number: 1366067 https://www.gov.uk/planning-inspectorate 2

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — 4 Keystone Crescent, Islington, London N1 9DS Appeal Decisions APP/V5570/W/25/3366692, APP/V5570/Y/25/3366693, APP/V5570/W/25/3366695, and APP/V5570/Y/25/3366696 Reasons 7. 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. Additionally, 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. 8. The listed building is a residential terrace that dates from 1845. The appeal buildings are two of the dwellings in the terrace. It is constructed in buff stock brick and is built to two storeys plus an attic and basement. The ground floor is elevated from the street by a set of steps with front facing sash windows alongside each front door that have a round head with margin lights. The terrace is set in a crescent shape.

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — 4 Keystone Crescent, Islington, London N1 9DS The rhythm of the terrace, the visual appeal of its curved form, retained historic fabric and interesting details like the shape of the ground floor windows are characteristics that contribute to its architectural and historic interest. 9. Additional interest is derived from surviving historic plan form, internal details such as staircases, and the more utilitarian appearance of the rear of the terrace. The rear façade is illustrative of the different status of the front and rear, with the architectural focus clearly given to the front. 10. The appeal buildings stand at the end of the original crescent, with additional buildings added to the west. They retain original windows, largely intact plan forms and original staircases. 11. The terrace stands in the CA. The area was developed between about 1830 and 1850 and comprises a dense arrangement of terraces, with a coherent character that has changed little since it was first laid out. The terrace at Keystone Crescent is a key contributor to the character and appearance of the area. 12. The proposal would see large extensions added to the roof of both buildings to form shower rooms to serve the second floor bedrooms.

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — 4 Keystone Crescent, Islington, London N1 9DS The extensions would occupy a large portion of the rear roof of both appeal buildings. They would thus alter a primary original aspect of the terrace and it would appear as though openings at attic level were limited originally to the front facing dormers. They would thus cause a degree of harm to the original form and appearance of the terrace. 13. However, they would have no impact on the finely executed front façade of the terrace, and they would sit neatly alongside the huge chimney breast. Their off- centre position would not be out of place in the context of the less formal rear façade, and in any case the ability to appreciate the appearance of the rear of the terrace is severely limited by its curved form and small gardens. Additionally, the rear of this part of the terrace is significantly hemmed in by substantial commercial buildings that stand close to its south elevation. 14. As a result, although the extensions would be large and of a scale that in many situations would be seen as dominant or obtrusive, the level of harm would be significantly reduced by the building’s context.

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — 4 Keystone Crescent, Islington, London N1 9DS Furthermore, they would read as additions, with the historic form of the roof still apparent and their impact would be limited to the rear, which has seen various alterations historically. https://www.gov.uk/planning-inspectorate 3

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — 4 Keystone Crescent, Islington, London N1 9DS Furthermore, they would read as additions, with the historic form of the roof still apparent and their impact would be limited to the rear, which has seen various alterations historically. https://www.gov.uk/planning-inspectorate 3

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — 4 Keystone Crescent, Islington, London N1 9DS Appeal Decisions APP/V5570/W/25/3366692, APP/V5570/Y/25/3366693, APP/V5570/W/25/3366695, and APP/V5570/Y/25/3366696 15. Horizontal timber boards are not a traditional material for cladding a roof extension, yet the vertical lines would help to lessen their massing, as would a dark finish. Additionally, timber cladding is a utilitarian material that is well suited to the functional appearance of the rear of the terrace. 16. The Council suggests that the character of the attic rooms would be altered by the proposal. However, the new rooms would be formed by simple lateral partitions that would retain the modest scale of the existing rooms. 17. The small dormers at the front of the building are without rainwater goods, which is a traditional arrangement. The proposed roof extensions would be significantly larger than these and would include gutters and downpipes. Finishing these in a dark colour to match the dark colour of the cladding would ensure that they do not look out of place. 18. The proposals include several other alterations. The submissions suggest that these have already received consent. They appear to be well considered, and I am satisfied that they preserve the significance of the listed building. 19.

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — 4 Keystone Crescent, Islington, London N1 9DS Paragraph 14.18 of Keystone Crescent (CA14) Conservation Area Design Guidelines 2002 (CA14) establishes that the roof line of a street is a major component of its character. Paragraph 14.16 of the guidance appears to suggest that roof extensions will only be allowed on two different groups of buildings, however this is stated in the context of roof extensions that are visible from street levels or public areas. In this case, the proposed roof extensions would have no discernible impact on the character or appearance of the wider area, as the area at the rear of this part of the terrace is tightly hemmed in and not subject to wider views. Therefore, the proposal would preserve the character and appearance of the CA. 20. A low level of harm to the significance of the listed building would arise from the roof extensions. In terms of the National Planning Policy Framework (Framework), the harm would be less than substantial but would nevertheless be of considerable importance and weight. Paragraph 215 of the Framework establishes that any harm should be weighed against the public benefits of the proposal. 21. The proposals would see the dwellings brought back into a good state of repair, which is much needed.

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — 4 Keystone Crescent, Islington, London N1 9DS Several small benefits would be included such as reinstated cornices and joinery, and the repairs to front railings. The stairs to the attic of No. 3 would be repaired. Repairs to No. 4 would include significant rebuilding at the rear because of structural failure. 22. The changes would provide two well-appointed dwellings, which would be pleasant to occupy. This would be good for the future conservation of the terrace, and their repair and reinstatement would also contribute to the supply of family housing locally on the basis that neither are currently in a suitable state to be occupied. These public benefits would outweigh the low level of less than substantial harm identified. 23. The Council suggests that the benefits of the proposals should not be taken into account as apart from the roof extensions the other work is already consented, and the public benefits could be achieved without the roof extensions. However, the other work has not been carried out and is included within the appeal https://www.gov.uk/planning-inspectorate 4

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — 4 Keystone Crescent, Islington, London N1 9DS Appeal Decisions APP/V5570/W/25/3366692, APP/V5570/Y/25/3366693, APP/V5570/W/25/3366695, and APP/V5570/Y/25/3366696 proposals. The balancing exercise needs to be undertaken to consider the proposals in their entirety, regardless of whether parts of a scheme have already been consented or one part of a proposal is or is not dependent on another. It is therefore correct that I should consider the benefit of the other works that are included within the same applications. 24. In summary, I have had special regard to the preservation of the listed building in accordance with the LBCA, and the great weight that should be given to the asset’s conservation in accordance with the Framework. I have found the impact to be acceptable on the basis that the low level of less than substantial harm is outweighed by the public benefits. The proposals would also accord with Policies DH1 and DH2 of the Islington Local Plan 2023, Urban Design Guide Supplementary Planning Document 2017, and CA14 which together seek to ensure that heritage assets are conserved. Conditions 25. I have had regard to the conditions suggested by the Council.

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — 4 Keystone Crescent, Islington, London N1 9DS I have considered these against the tests in the Framework and the advice in the Planning Practice Guidance. I have imposed conditions for the planning permissions that specify the approved plans as this provides certainty. 26. I have imposed condition 3 of the planning permissions, conditions 2 to 6 of Appeal B and conditions 2 to 8 of Appeal D to preserve the character and appearance of the conservation area and the significance of the listed building. Conclusion 27. For the reasons above, the appeals should be allowed.

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — A Tucker INSPECTOR https://www.gov.uk/planning-inspectorate 5

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — A Tucker INSPECTOR https://www.gov.uk/planning-inspectorate 5 Appeal Decisions APP/V5570/W/25/3366692, APP/V5570/Y/25/3366693, APP/V5570/W/25/3366695, and APP/V5570/Y/25/3366696 Schedule of Conditions – Appeal A 1) The development hereby permitted shall begin not later than 3 years from the date of this decision. 2) The development hereby permitted shall be carried out in accordance with the following approved plans: DMT/03/00/01, DMT/03/001/B1, DMT/03/001/00, DMT/03/001/01, DMT/03/001/02, DMT/03/01/B1, DMT/03/01/00, DMT/03/01/01, DMT/T03/01/02, DMT/03/06/01, DMT/03/07/01, DMT/03/07/02, DMT/03/07/03, DMT/03/07/04, DMT/03/07/05, DMT/03/07/07, DMT/03/40/01, DMT/03/40/02, DMT/03/05/B1 Rev B, DMT/03/05/00 Rev B, DMT//03/06/03 Rev A, DMT/03/07/09 Rev B, DMT/03/40/12, DMT/03/40/10, DMT/03/40/11, DMT/03/05/01 Rev A, DMT/03/05/03 Rev A, Window repair and replacement schedule February 2025, and Sustainable Design and Construction Statement November 2024. 3) The development hereby approved shall be carried out in accordance with the schedule of materials noted on the approved plans and shall be maintained as such thereafter. https://www.gov.uk/planning-inspectorate 6

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — A Tucker Appeal Decisions APP/V5570/W/25/3366692, APP/V5570/Y/25/3366693, APP/V5570/W/25/3366695, and APP/V5570/Y/25/3366696 Schedule of Conditions – Appeal B 1) The works hereby permitted shall begin not later than 3 years from the date of this decision. 2) All external and internal works and finishes and works of making good to the retained fabric shall match the adjacent work with regard to methods used and to material, colour, texture and profile. All such works and finishes shall be maintained as such thereafter. 3) Detailed drawings or samples of materials as appropriate, in respect of the following, shall be submitted to and approved in writing by the Local Planning Authority before the relevant part of the works is begun. The works shall not be carried out other than in accordance with the details hereby approved and shall be maintained as such thereafter: a) Notwithstanding drawing No. DMT/03/40/11, details of handrails to new front basement entrance steps. b) Details of the secondary glazing. c) Detailed drawings of the modifications to the stair between the first and second floor. d) Detailed drawings of the replacement sash windows. e) Details of the cladding for the dormer including its finished colour.

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — A Tucker 4) Prior to the alteration of existing or installation of any new services, plans and detailed drawings depicting new service runs, including soil vent pipes and the location and design of extract vents shall be submitted to and approved in writing by the Local Planning Authority. The works shall be carried out in accordance with the approved details. 5) The localised repointing shall be carried out using hand held tools and no power driven tools of any descriptions shall be used in connection with the repointing, and the pointing shall be lime based to match the existing colour of pointing and shall be flush or slightly recessed and shall be maintained as such thereafter. 6) The gutter and downpipe for the dormer hereby approved shall be metal and painted black, and shall be maintained as such thereafter. https://www.gov.uk/planning-inspectorate 7

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — A Tucker Appeal Decisions APP/V5570/W/25/3366692, APP/V5570/Y/25/3366693, APP/V5570/W/25/3366695, and APP/V5570/Y/25/3366696 Schedule of Conditions – Appeal C 1) The development hereby permitted shall begin not later than 3 years from the date of this decision. 2) The development hereby permitted shall be carried out in accordance with the following approved plans: DMT/04/00/01, DMT/04/001/B1, DMT/04/001/00, DMT/04/001/01, DMT/04/001/02, DMT/04/01/B1, DMT/04/01/00, DMT/04/01/01, DMT/04/01/02, DMT/04/06/01, DMT/04/07/01, DMT/04/07/02, DMT/04/07/03, DMT/04/07/04, DMT/04/07/09 Rev B;DMT/04/07/07; DMT/04/40/01, DMT/04/40/02; DMT/04/40/03, DMT/04/40/04; DMT/04/40/05, DMT/04/40/06, DMT/04/40/07, DMT/04/40/08, DMT/04/40/09, DMT/04/05/B1 Rev B; DMT/04/05/00 Rev B; DMT/04/05/01 Rev B; DMT/04/05/03 Rev B; DMT/04/06/03 Rev A, DMT/04/07/05, DMT/04/05/03 Rev B; DMT/04/07/09 Rev B, Window repair and replacement schedule February 2025, Sustainable Design and Construction Statement November 2024, and Structural Statement Ref 231403/N. 3) The development hereby approved shall be carried out in accordance with the schedule of materials noted on the approved plans and shall be maintained as such thereafter.

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — A Tucker https://www.gov.uk/planning-inspectorate 8

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — A Tucker https://www.gov.uk/planning-inspectorate 8 Appeal Decisions APP/V5570/W/25/3366692, APP/V5570/Y/25/3366693, APP/V5570/W/25/3366695, and APP/V5570/Y/25/3366696 Schedule of Conditions – Appeal D 1) The works hereby permitted shall begin not later than 3 years from the date of this decision. 2) All external and internal works and finishes and works of making good to the retained fabric shall match the adjacent work with regard to methods used and to material, colour, texture and profile. All such works and finishes shall be maintained as such thereafter. 3) Detailed drawings or samples of materials as appropriate, in respect of the following, shall be submitted to and approved in writing by the Local Planning Authority before the relevant part of the works is begun. The works shall not be carried out other than in accordance with the details hereby approved and shall be maintained as such thereafter: a) Details of the secondary glazing. b) Detailed drawings of the new or replacement sash windows. c) Details of the cladding for the dormer including its finished colour.

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — A Tucker 4) Prior to the alteration of existing or installation of any new services, plans and detailed drawings depicting new service runs, including soil vent pipes and the location and design of extract vents shall be submitted to and approved in writing by the Local Planning Authority. The works shall be carried out in accordance with the approved details. 5) The brickwork bond for the replacement brickwork on the rear elevation shall match the original bond on the building and the existing bricks shall be re-used and where additional bricks are required they shall match existing bricks in terms of size, texture and colour and shall be maintained as such thereafter. 6) The localised repointing shall be carried out using hand held tools and no power driven tools of any descriptions shall be used in connection with the repointing, and the pointing shall be lime based to match the existing colour of pointing and shall be flush or slightly recessed and shall be maintained as such thereafter. 7) The gutter and downpipe for the dormer hereby approved shall be metal and painted black, and shall be maintained as such thereafter. 8) All fireplace grates shall be retained in situ and shall not be removed.

3 Keystone Crescent, LONDON, N1 9DS — London Borough of Islington — A Tucker https://www.gov.uk/planning-inspectorate 9