Skip to content

20 Carlton House Terrace London SW1Y 5AN

24/00549/NMANon-material amendmentsRefused
Discharge / amendments

Refused on 8 February 2024

Council decision: Application RefusedDelegated (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

Amendments to planning permission dated 28 July 2023 (23/02725/FULL) for the variation of Condition 1 and 11 of planning permission dated 20 October 2022 (22/04903/FULL) for the demolition of existing mansard roof and roof level plant and construction of two storey vertical roof addition with extensions at fourth, fifth, sixth and seventh floor levels for additional office (Class B1) floorspace. Use of the lower ground and basement level for flexible/alternative office (Class B1)/retail (Class A1)/leisure uses (Class D2); car parking, cycle parking, ancillary office uses and mechanical plant. Alterations to the existing building including new windows and entrance, new terraces to eighth and tenth floor levels and new plant enclosure at roof level and associated works; and amendments to car parking provision (retention of the public car park), alterations to the cycle parking provision and basement layouts and reduction in flexible commercial floorspace; design modifications to the Carlton House Terrace elevation including an additional entrance, pavement lights, replacement railings and re-alignment of a section of the south facade; alterations to the lower ground floor glazing on the west elevation, a new stairwell and platform lift to roof terrace (level 10), widening of central core to accommodate emergency access and fire-fighting lifts, realignment of level 10 balustrade and alterations to south-west lift overrun and amendment to the wording of Condition 11 to include the word 'pergolas'; NAMELY, to amend the wording of Condition 10 to allow the provision of an external lighting strategy.

Received
29 January 2024
Decision level
Delegated (officer decision)
Ward
St James's
  1. Received29 Jan
  2. Validated29 Jan
  3. Consult.
  4. Target26 Feb
  5. Decided8 Feb

Decided in 10 days (council typically 49)

About this application

This is an application to amend a permission at 20 Carlton House Terrace London SW1Y 5AN. Westminster has handled 604 applications of this type. This one was decided in 10 days, 6 weeks quicker than Westminster's typical decision time. The site is in the St James's conservation area, with 14 listed buildings nearby. There have been 8 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.

88% of amendment 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 5AN
Application type
Non-material amendments
Scale / size
Small

Planning application dates

Date validated
29 January 2024
Target decision date
26 February 2024

Applicant and agent

Agent
DP9
Agent address
100 Pall Mall London SW1Y 5NQ

Planning decision

Statutory period
28 days

Additional information

Planning Portal ID
PP-12764755
Comments
0
Documents
8

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: The Royal Marines MemorialOn or next to this site · +1 more
  • Article 4 direction: Article 4 Basement Development Permitted Rights Removed+1 more
  • Registered park and garden: St James'S ParkPart of the site
  • Brownfield land register: Admiralty Arch The Mall London SW1A 2DYRegister site at or near this address
  • Flood zone 1: Low probability (rivers and sea)
Also checked, none recorded (19)

flood storage areas, tree preservation orders, green belt, scheduled monuments, World Heritage Sites, World Heritage Site buffer zones, 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 and heritage coasts.

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.

Planning history at this site

10 other applications at this property, newest first.

  1. 2025
    10 Oct

    Installation of external lighting to the eighth and tenth floor terraces.

    ApprovedApplication25/06975/FULL
  2. 2025
    18 Sep

    Retrospective full application for the installation of pergola structure at L8 terrace, new bi-fold doors at…

    ApprovedFull planning permission25/05651/FULL
  3. 2025
    14 Aug

    Retrospective amendments to the glazed pavilion at tenth floor terrace level.

    ApprovedFull planning permission25/05734/FULL
  4. 2024
    13 Dec

    Details terraces, hard and soft landscaping, landscape management plan, and rooting environment pursuant to…

    PendingDischarge of conditions24/08704/ADFULL
  5. 2024
    11 Dec

    Detailed drawings of a hard and soft landscaping scheme to the eighth and tenth floor terrace areas and…

    PendingDischarge of conditions24/08625/ADFULL
  6. 2024
    23 Oct

    Amendments to planning permission dated 28th July 2023 (RN 23/02725/FULL

    PendingNon-material amendment24/07372/NMA

Source: Westminster

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

Track this application

Get email alerts when there is a planning decision or status change.

Get email alerts near SW1Y

New planning applications delivered to your inbox daily.

Around this site

For applicants and trades

Planning something similar?

See what the council approved and refused on your street for the project you have in mind. Pick your home and get the evidence before you pay for drawings.