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12 Duke Street St James's London SW1Y 6BN

17/09563/FULLApplication for full Planning PermissionApproved
Full

Approved on 20 December 2017

Council decision: Application PermittedDelegated (officer decision)

Approximate site (title boundary)
Boundary © HM Land Registry, © Ordnance Survey · details

This information is subject to Crown copyright and database rights 2026 and is reproduced with the permission of HM Land Registry. The polygons (including the associated geometry, namely x, y co-ordinates) are subject to Crown copyright and database rights 2026 Ordnance Survey AC0000851063. Conditions of use.

Proposal

Variation of Condition 1 of planning permission dated 03 May 2017 (RN: 17/02174/FULL) which varied permission dated 23 December 2015 (RN: 15/09261/FULL) for lowering of the basement floor level, erection of three storey rear extension at first, second and third floor levels, enlargement of the top/fourth floor mansard roof and creation of roof terrace at fourth floor level, and installation of mechanical plant at roof level in connection with the amalgamation of Nos. 12 and 13 to create a single art gallery at basement and ground floor level, with ancillary offices at first and second floor levels and creation of a self-contained residential flat (Class C3) at third and fourth floor levels, namely to amend the approved drawing numbers to allow amendments to the Mason's Yard rear entrance portico to the building with the addition of a metal security gate.

Received
27 October 2017
Decision level
Delegated (officer decision)
Ward
St James's
Agent
Tomef Design Limited
  1. Received27 Oct
  2. Validated27 Oct
  3. Consult.
  4. Target22 Dec
  5. Decided20 Dec

Decided in 54 days (council typically 49)

About this application

This is a full planning application for a rear extension at 12 Duke Street St James's London SW1Y 6BN. Westminster has handled 4,484 applications of this type. This one was decided in 54 days, 5 days longer than Westminster's typical decision time. The site is in the St James's conservation area, with 14 listed buildings nearby. There have been 2 other applications at this address. In the past year there have been 478 applications across St James's. We hold 969 applications in total for the SW1Y postcode area.

86% of full applications at City of Westminster were approved. Across all application types, the council typically decides in about 7 weeks (median).

Based on decided applications received in the last 3 years.Planning something similar? See what gets approved on your street

Application details

Postcode
SW1Y 6BN
Application type
Application for full Planning Permission
Scale / size
Small

Planning application dates

Date validated
27 October 2017
Consultation expiry
1 December 2017
Target decision date
22 December 2017

Applicant and agent

Agent
Tomef Design Limited
Agent address
World's End Studios 132-134 Lots Road London SW10 0RJ

Planning decision

Statutory period
56 days

Publicity

Last advertised
10 November 2017
Advertisement expiry
1 December 2017

Additional information

Planning Portal ID
PP-06493142
Comments
0
Documents
12

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, Duke StreetOn or next to this site
  • 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.

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

© Environment Agency copyright and/or database right 2026. All rights reserved. Flood Map for Planning, Open Government Licence v3.0.

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

  1. 2017
    27 Oct

    Variation of Condition 1 of planning permission dated 03 May 2017 (RN: 17/02174/FULL

    This applicationApprovedVariation of conditions (s73)17/09563/FULL
  2. 2015
    5 Oct

    Lowering of the basement floor level, erection of three storey rear extension at first, second and third…

    ApprovedApplication for full Planning PermissionPart of15/09261/FULL

Source: Westminster

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

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