1 Marylebone High Street London W1U 4DL
Proposal
Amendments to planning permission dated 18 June 2025 (RN: 24/08179/FULL) for 'Rear extension to existing building, formation of new roof terrace including rooftop pavilion, new external plant, replacement of existing windows with double glazing and minor alterations to building facade including new entrance.' Namely, changes in window arrangement on rear and north elevation of the building.
- Received
- 30 March 2026
- Decided
- 4 June 2026 · Application Permitted
- Council
- City of Westminster
- ReceivedSubmitted30 Mar
- ValidatedValidated30 Mar
- Consult.Consultation
- TargetTarget Date
- DecidedDecided4 Jun
Decided in 66 days
This is a planning application for a rear extension at 1 Marylebone High Street London W1U 4DL. 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 66 days, 12 days longer than Westminster's median. The site is in the Harley Street conservation area, with 8 listed buildings nearby. There have been 2 other applications at this address. We hold 1,036 applications in total for the W1U postcode area.
Application Details
Applicant & Agent
Planning Application Dates
Planning Decision
Publicity
Appeal
Additional Information
Source: Westminster
Contains public sector information from the Planning London Datahub, licensed under the Open Government Licence v3.0.
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Planning history at this site
5 other applications at this property, newest first.
- 202610 Sep
Registering address details for four office units and updating PAF for commercial units of 1, 1A, and 2…
PendingAll OtherSNN26/00076 - 20266 Aug
Removal of existing Luxcrete panelled pavement and replacement with York stone paving slabs outside 1…
ApprovedApplication26/05334/FULL - 20258 Dec
Use of first and second floors as office use (Class E).
ApprovedApplication25/08905/FULL - 202519 Sep
Detailed samples of the cladding for the rooftop pavilion pursuant to condition 4 of planning permission…
ApprovedDischarge of conditions25/06757/ADFULL - 20251 Aug
Details of shopfront, new windows, new glazed entrance door, refuse & recycling storage, all flood resilient…
ApprovedAll Other25/05396/ADFULL
Planning constraints
Designations that overlap or adjoin the site outline.
- Conservation area: Harley Street
- Article 4 direction: Article 4 Basement Development Permitted Rights Removed+1 more
- Flood zone 1: Low probability (rivers and sea)
Also checked, none recorded (22)
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, 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 2026-10-09. 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.
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