11 - 12 St James's Square London SW1Y 4LB

25/09401/LBCApproved

Approved

Site boundary (council red line)

Proposal

External and internal alterations, including the partial removal of non-heritage additions and the remodelling of the 1980s rear extension, provision of terraces and roof garden and associated works. (Linked to 25/09400/FULL)

Submitted: 22 December 2025
Council: City of Westminster

ReceivedSubmitted22 Dec
ValidatedValidated
Consult.Consultation
TargetTarget Date
DecidedDecided

About this application

This is a planning application for a rear extension at 11 - 12 St James's Square London SW1Y 4LB. Westminster has handled 27,108 applications of this type. It has been with the council since 22 December 2025 and is still awaiting a decision. The site is in the St James's conservation area, with 20 listed buildings nearby. There have been 3 other applications at this address. We hold 969 applications in total for the SW1Y postcode area.

Application details

Postcode: SW1Y 4LB

Site constraints

Checking the site

2/3

Council recordsAppealsFlood risk

Designations that overlap or adjoin the site outline.

Conservation area: St James's
Listed building: Grade II*: 11, St James'S Square Sw1On this site · +5 more
Article 4 direction: Article 4 Basement Development Permitted Rights Removed+1 more
Flood zone 1: Low probability (rivers and sea)

Also checked, none recorded (21)

flood storage areas, tree preservation orders, green belt, scheduled monuments, World Heritage Sites, World Heritage Site buffer zones, registered parks and gardens, registered battlefields, Heritage at Risk entries, nutrient neutrality catchments, national parks, National Landscapes, SSSIs, Special Areas of Conservation, Special Protection Areas, Ramsar sites, ancient woodland, national nature reserves, local nature reserves, heritage coasts and brownfield registers.

A guide only, from official open data; it is not a planning search. Flood zones cover rivers and sea, not surface water.

Data © Crown copyright and others · sources and licences

Contains public sector information from planning.data.gov.uk (MHCLG and local planning authorities), licensed under the Open Government Licence v3.0. © Crown copyright and database right 2026.

© Historic England 2026. Contains Ordnance Survey data © Crown copyright and database right 2026. The Historic England GIS Data contained in this material was obtained on 2026-11-03. The most publicly available up to date Historic England GIS Data can be obtained from HistoricEngland.org.uk.

Contains Ordnance Survey data © Crown copyright and database right 2026.

Source: Office for National Statistics licensed under the Open Government Licence v.3.0. Contains OS data © Crown copyright and database right 2026.

Associated applications

2025
22 Dec
External and internal alterations, including the partial removal of non-heritage additions and the…
ApprovedApplicationPart of25/09400/FULL
2025
22 Dec
External and internal alterations, including the partial removal of non-heritage additions and the…
This applicationApprovedListed building consent25/09401/LBC

Planning history at this site

5 other applications at this property, newest first.

Source: Westminster

Contains public sector information from the Planning London Datahub, licensed under the Open Government Licence v3.0.

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