Planning application
25/09271/FULL
12 Chester Street London SW1X 7BB
Proposal
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.
As published by the council, reference 25/09271/FULL
Timeline
Dates from the published record
-
22 Dec 2025
Received by Westminster
-
8 May 2026
Decision issued: Application Permitted
-
20 Jul 2026
Added to PlanIndex
What a grant of permission means
The process from here
Permission has been granted, usually subject to conditions listed on the decision notice, some of which must be discharged before work starts. The decision notice on the council portal sets out exactly what was approved.
Work must normally begin within three years of the decision or the permission lapses. Neighbours cannot appeal a grant; challenging one means judicial review of how the decision was made, within tight time limits.
About full applications applications
How this application type works
A full application seeks permission for a complete, detailed proposal in one go: siting, design, access and landscaping are all fixed at this stage. It is the standard route for new buildings, conversions and changes of use. The statutory target is eight weeks for smaller schemes and thirteen weeks for major development, though complex cases often take longer by agreement.
Nearby applications
Within 500 metres
-
26/00535/NMA Granted
12 Chester Street London SW1X 7BB
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'.
-
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.
-
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.
-
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.
-
26/00077/FULL Granted
24 Chester Street London SW1X 7BL
Erection of two storey rear extension at ground and lower ground floor level and associated works.
-
26/00078/LBC Granted
24 Chester Street London SW1X 7BL
Erection of two storey rear extension at ground and lower ground floor level and associated works.
Other full applications applications
In Westminster
-
26/04824/ADFULL Granted
New Zealand House 80 Haymarket London SW1Y 4TE
Detailed design and specification of new blinds to NZH based on mock-up trials on-site. pursuant to condition 32 (i) of planning permission dated 8th April 2024 (23/00571/FULL).
-
26/04829/ADFULL Granted
New Zealand House 80 Haymarket London SW1Y 4TE
Details of external and internal signage strategy pursuant to Condition 33(E) of planning permission dated 8th April 2024 (RN: 23/00571/FULL)
-
26/04841/ADFULL Granted
29 Henstridge Place London NW8 6QD
Details of the facing materials you will use, including glazing, and elevations and roof plans annotated to show where the materials are to be located pursuant to condition 5 of planning permission dated 18th November 2025 (RN:25/06159).
-
26/04989/FULL Awaiting decision
1 Kildare Terrace London W2 5JT
Erection of a mansard roof extending over the main house and side wing, replacement lower ground rear extension with roof terrace above, lowering of lower ground floor slab, installation of an air source heat pump in rear garden, new front boundary treatment, and new second floor window on the north elevation.
-
26/04986/FULL Awaiting decision
Inver Court Inverness Terrace London W2 6JB
Replacement of combustible materials in the render facades; timber decking and plastic soffits/ fascias to terraces with non-combustible materials on the 5th and 6th floors.