Planning application
12 Chester Street London SW1X 7BB
Works: Extension Loft or dormer Windows or glazing
Permission granted. Work must normally begin within three years of the decision or the permission lapses.
Proposal
Amendment to planning permission dated 24th July 2025 (RN 24/05883/FULL) for the Excavation of a new basement level. Replacement of existing rear extension at first, second and third with a new rear extension (first to third floor level) with flat roof. Erection of an extension at rear ground floor level. Removal of the existing kitchen rooflight and extension of existing terrace at first floor level. Replacement of existing windows and French doors with new; NAMELY to amend the description of development to omit 'Excavation of a new basement level'; amended description of development to read as follows: 'Replacement of existing rear extension at first, second and third with a new rear extension (first to third floor level) with flat roof. Erection of an extension at rear ground floor level. Removal of the existing kitchen rooflight and extension of existing terrace at first floor level. Replacement of existing windows and French doors with new'.
As published by the council, reference 26/00535/NMA
Application record
- Reference
- 26/00535/NMA
- Type
- Non-material amendments
- Status
- Decided
- Decision
- Granted As published: Application Permitted
- Received
- 29 Jan 2026
- Validated
- 29 Jan 2026
- Decided
- 16 Mar 2026
- Ward
- Knightsbridge & Belgravia
- Decision by
- Delegated Decision
- Postcode
- SW1X 7BB
Site history
Applications at this address on the Westminster register
This site has had 5 applications since 2025: 3 approved, 0 refused.
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26/02886/LBC Awaiting decision
12 Chester Street London SW1X 7BB
Replacement of existing rear extension at first, second and third with a new rear extension (first to third floor level) with flat roof. Erection of an extension at rear ground floor level. Removal of the existing kitchen rooflight and extension of existing terrace at first floor level. Replacement of existing windows and French doors with new; and alterations to French door width at rear first floor level.
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26/01507/FULL Awaiting decision
12 Chester Street London SW1X 7BB
Variation of condition 1 of planning permission dated 24th July 2025 (RN 24/05883/FULL) for the Excavation of a new basement level. Replacement of existing rear extension at first, second and third with a new rear extension (first to third floor level) with flat roof. Erection of an extension at rear ground floor level. Removal of the existing kitchen rooflight and extension of existing terrace at first floor level. Replacement of existing windows and French doors with new. NAMELY, to omit the approved basement and minor amendments to the upper floors.
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25/09271/FULL Granted
12 Chester Street London SW1X 7BB
Installation of air conditioning units within an acoustic enclosure at roof level and replacement of the existing lead flat roof with a new lead flat roof.
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25/09272/LBC Granted
12 Chester Street London SW1X 7BB
Installation of air conditioning units within an acoustic enclosure at roof level and replacement of the existing lead flat roof with a new lead flat roof.
Timeline
Dates from the published record
-
29 Jan 2026
Received by Westminster
-
16 Mar 2026
Decision issued: Application Permitted
-
21 Jul 2026
Added to PlanIndex
Who's behind it
Company information only, from the register and Companies House
Thompson Planning Ltd Agent, a planning consultancy registered in Epping
Active · incorporated 2017 · Epping
3 applications on PlanIndex · across 3 councils
Trade members see everything this firm has filed, how it was decided, and get an email the day it files again.
See their track recordDocuments
Plans, drawings, consultee responses and the officer's report
8 documents on file for this application
A planning file usually holds the application form, drawings and site plans, consultee responses, the officer's report and the decision notice.
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Open the documentsWhat this grant of permission means
Westminster granted permission on 16 March 2026, subject to any conditions on the decision notice. Work must normally begin within three years or the permission lapses. More in our guide to what happens after a planning decision.
About amendment applications
An amendment application makes limited changes to a permission that already exists; anything beyond modest adjustment needs a fresh application. More in our guide to planning application types.
Nearby applications
Within 0.3 miles
-
12 Chester Street London SW1X 7BB
Installation of air conditioning units within an acoustic enclosure at roof level and replacement of the existing lead flat roof with a new lead flat roof.
Granted Full applications 22 docs -
12 Chester Street London SW1X 7BB
Installation of air conditioning units within an acoustic enclosure at roof level and replacement of the existing lead flat roof with a new lead flat roof.
Granted Heritage and listed buildings 17 docs -
12 Chester Street London SW1X 7BB
90% historically approved · decision due ~26 Jun
Replacement of existing rear extension at first, second and third with a new rear extension (first to third floor level) with flat roof. Erection of an extension at rear ground floor level. Removal of the existing kitchen rooflight and extension of existing terrace at first floor level. Replacement of existing windows and French doors with new; and alterations to French door width at rear first floor level.
Awaiting decision Heritage and listed buildings Extension Loft or dormer +1 12 docs -
12 Chester Street London SW1X 7BB
87% historically approved · decision due ~4 May
Variation of condition 1 of planning permission dated 24th July 2025 (RN 24/05883/FULL) for the Excavation of a new basement level. Replacement of existing rear extension at first, second and third with a new rear extension (first to third floor level) with flat roof. Erection of an extension at rear ground floor level. Removal of the existing kitchen rooflight and extension of existing terrace at first floor level. Replacement of existing windows and French doors with new. NAMELY, to omit the approved basement and minor amendments to the upper floors.
Awaiting decision Full applications Extension Loft or dormer +1 17 docs -
24 Chester Street London SW1X 7BL
Erection of two storey rear extension at ground and lower ground floor level and associated works.
Granted Full applications Extension 41 docs -
24 Chester Street London SW1X 7BL
Erection of two storey rear extension at ground and lower ground floor level and associated works.
Granted Heritage and listed buildings Extension 34 docs
Other amendment applications
In Westminster
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26/06232/NMA Awaiting decision
37 Trevor Place London SW7 1LE
Amendments to planning permission dated 17th July 2026 (RN 26/03030/FULL) for the Alterations including enlargement of louvres and installation of new plant in basement; landscaping of roof terrace; second floor windows replaced with door sets; partial demolition at ground and first floor levels to create new lightwell and landscaped courtyard. NAMELY, addition of a free-standing sauna to the second-floor roof terrace.
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26/06256/NMA Awaiting decision
Queens Court Queensway London W2 4QN
Amendments to planning permission dated 21st May 2026 (RN:25/05013/FULL) for Variation of conditions 1, 3, 8, 9 and 17 of planning permission dated 11th May 2022 (RN 18/09765/FULL) for the Change of use of rear part of Queensway Market to Retail, Financial and Professional services, Office and Restaurant (within Class E) use and 5 residential units facing Princes Court, reconfiguration of retail units along Queensway including introduction of Retail uses at Nos.23 and 33 (current entrances to Queensway Market) and use of Nos.25 and 41-43 Queensway as Restaurant uses, installation of new shopfronts to Nos.23 to 43 Queensway 23-43, erection of infill extension to rear at ground floor level, erection of two new pavilion structures for Retail use and associated new hard and soft landscaping on land between Queens Court and Princes Court, installation of green roofs, rooflights and mechanical plant within enclosures to first floor level roofs between projecting rear wings of Queens Court installation of kitchen extract ducts to rear elevations, and associated cycle parking, waste storage, plant and other ancillary alterations ('Application 2'). Namely, to vary the hours of operation for the refrigeration plant controlled by condition 6.
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26/06251/NMA Awaiting decision
19 Cumberland Street London SW1V 4LS
Amendments to planning permission dated 20th March 2026 (RN:25/08960/FULL) for Lower ground floor rear infill extension with terrace above, replacement of rear first floor conservatory, new roof level rear single dormer with access to third floor roof terrace, alterations to windows and external refurbishment, namely the change of conservatory gable roof to a flat GRP roof.
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26/06201/NMA Awaiting decision
Almack House 28 King Street St James's London SW1Y 6QW
Amendments to planning permission dated 16th April 2026 (RN:26/01487/FULL) for Installation of a mechanical plant at lower ground floor and installation of two grilles to two lower ground floor windows, namely change to approved grille.
-
26/06212/NMA Awaiting decision
10 - 11 Lancaster Gate London W2 3LH
Amendment to Condition 12 (Whole Life Carbon) of planning permission dated 19th April 2024 (RN 23/04044/FULL) for Change of use from hotel to residential use (Class C3) with associated internal alterations to create 11 new units and external alterations comprising reconfiguration and recladding of the rear extension and restoration of the existing building. Namely to include additional requirement to evidence and justify where benchmarks cannot be achieved, consider mitigation measures and if none, evidence that all mitigation measures have been exhausted. (Linked with RN 26/06213/ADFULL)