Planning application
25/08713/FULL
3 Great Cumberland Mews London W1H 7DZ
Proposal
Conversion of the existing ground-floor garage into habitable residential accommodation; enlargement of the rear window in the existing utility room; and installation of air conditioning unit at rear ground floor patio.
As published by the council, reference 25/08713/FULL
Timeline
Dates from the published record
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28 Nov 2025
Received by Westminster
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15 Jan 2026
Validated
Checked as complete and ready for consideration.
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16 Apr 2026
Decision issued: Application Permitted
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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
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26/02789/ADFULL Awaiting decision
3 Great Cumberland Mews London W1H 7DZ
Details of appropriate arrangements to secure measures to mitigate the potential increased demand for on-street residents car parking in the vicinity of the site pursuant to condition 7 of planning permission dated 16th April 2026 (RN:25/08713/FULL)
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26/02789/FULL Awaiting decision
3 Great Cumberland Mews London W1H 7DZ
Removal of Condition 7 of planning permission dated 16th April 2026 (RN: 25/08713/FULL) to remove the requirement to secure measures to mitigate the potential increased demand for on-street residents car parking in the vicinity of the site.
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25/06754/FULL Awaiting decision
22 Seymour Place London W1H 7NJ
Retention of the existing extract duct with brick cladding and associated fans, and duct attenuation, along with the installation of three AC units within an acoustic enclosure at the rear ground-floor roof level.
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26/04527/ADV Awaiting decision
Basement And Ground Floor 11 Seymour Place London W1H 5AN
Diaply of non illuminated vinyl window display measuring 1.8m x 0.7m, 1.8m x 0.7m, 0.4m x 0.82m, 0.97m x 0.675m with an art installation of 5 vinyls on the external ground floor windows in partnership with the Baker Street Quarter Partnership and University of Westminster.
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07/01369/FULL Refused
The Court House 165 Seymour Place London W1H 5BD
Alterations to residential redevelopment scheme approved 5 August 2003 (as amended 1 June 2004), namely retention of basement car park layout. [Property previously known as 163A Seymour Place]
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05/01082/FULL Granted
Clarewood Court Seymour Place London W1H 5BD
Retention of 6 wall-mounted air conditioning units and installation of an acoustic screen in rear internal lightwell serving No. 53.
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26/04829/ADFULL Granted
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Details of external and internal signage strategy pursuant to Condition 33(E) of planning permission dated 8th April 2024 (RN: 23/00571/FULL)
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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).
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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.
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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.