25 - 27 St George Street London W1S 1FS

25/07446/NMAPermitted

Proposal

Amendments to planning permission dated 11th August 2025 (RN 25/01410/FULL) for the Alterations to the elevations on St. George St and Masons Arms Mews; removal of the car lift to the basement parking from Masons Arms Mews; extensions at fourth, fifth, sixth and seventh floor levels for use as office accommodation (Class E) with new terraces at fourth, fifth, sixth and seventh floor levels. Installation of PV panels and green roof at main roof level; planting on the terraces; new external stair in the lightwell on the southern side of the building; creation of a new lightwell on the St. George Street side of the building including railings; new cycle parking facilities and associated works. NAMELY, to increase the roof height by 300mm; bring the building line forward by 993mm at seventh floor level; and insertion of additional louvres at the rear of the building at sixth floor level.

Received: 15 October 2025
Decided: 21 January 2026
Council: City of Westminster

Site boundary (council red line)

ReceivedSubmitted15 Oct
ValidatedValidated
Consult.Consultation
TargetTarget Date
DecidedDecided21 Jan

Decided in 98 days

This is a planning application for an extension at 25 - 27 St George Street London W1S 1FS. Westminster has handled 26,489 applications of this type and approves 88% of them, typically deciding them in 54 days. This one was decided in 98 days, 6 weeks longer than Westminster's median. The site is in the Mayfair conservation area, with 16 listed buildings nearby. There have been 6 other applications at this address. We hold 773 applications in total for the W1S postcode area.

Application Details

Reference

25/07446/NMA

Address

25 - 27 St George Street London W1S 1FS

Postcode

W1S 1FS

Local Authority

Westminster

Decision Status

Permitted

Applicant & Agent

Planning Application Dates

Date Decided

21 January 2026

Date Submitted

15 October 2025

Planning Decision

Publicity

Appeal

Additional Information

Coordinates

51.512960, -0.143051

Enriching application data

2/3

Council recordsAppealsFlood risk

Source: Westminster

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

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Associated applications

Planning history at this site

2 other applications at this property, newest first.

Planning constraints

Designations that overlap or adjoin the site outline.

Conservation area: Mayfair
Article 4 direction: Article 4 Basement Development Permitted Rights Removed+1 more
Brownfield land register: Nash House, 13 St George Street London W1S 1FERegister site at or near this address
Flood zone 1: Low probability (rivers and sea)

Also checked, none recorded (21)

flood storage areas, listed buildings, 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 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.

© 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 2026-10-09. The most publicly available up to date Historic England GIS Data can be obtained from HistoricEngland.org.uk.

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