3A Devonshire Mews South London W1G 6QW Data via plota.co.uk

26/06129/FULL - Full Planning Permission Application Pending
Extensions & alterations

Proposal

Replacement of three existing windows facing onto rear internal courtyard with timber framed double glazed casement windows. Data via plota.co.uk

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View original council record ↗Last checked

Application progress

✓
Received
8 Sept 2026
✓
Validated
22 Sept 2026
Decision
Expected by 17 Nov 2026

This application is under consideration - no decision has been issued yet. Plota predicts a decision between 12 Nov 2026 and 21 Nov 2026, from Westminster's recent extensions. Comments are open until 28 Oct 2026.

Comment on this application ↗

Documents 10

Statements & assessments 2

PDF SUSTAINABLE DESIGN STATEMENT Background Papers · 22 Sept 2026 View ↗ PDF HERITAGE STATEMENT Design and Access Statement · 8 Sept 2026 View ↗

Plans & drawings 5

PDF SITE PLAN AND BLOCK PLAN Location Plan · 8 Sept 2026 View ↗ PDF EXISTING PLANS Drawing · 8 Sept 2026 View ↗ PDF PROPOSED WINDOW PROFILES Drawing · 8 Sept 2026 View ↗ PDF PROPOSED ELEVATIONS Drawing · 8 Sept 2026 View ↗ PDF EXISTING ELEVATIONS Drawing · 8 Sept 2026 View ↗

Application forms 1

PDF APPLICATIONFORMREDACTED Application Form · 8 Sept 2026 View ↗

Other documents 2

PDF RECEIPT OF APPLICATION Other · 15 Sept 2026 View ↗ PDF 1ST INVALID LETTER Background Papers · 15 Sept 2026 View ↗

All documents on the council site ↗

Site constraints 8

Grade II listed: 1-6, Upper Wimpole Street W1
List entry 1274702 · 27 m away · 48 more listed buildings within 150 m (11 Grade II*, 37 Grade II)
Listed building consent is needed for work that affects the special interest of a listed building, inside or out, on top of planning permission. Setting can be a consideration for buildings nearby; there is no fixed radius.
Show the other 48 with distances
Historic England ↗
Harley Street conservation area
Demolition needs planning permission and permitted development is restricted.
The council must give weight to preserving or enhancing the area's character and appearance. Not every council has published its boundaries as open data.
Council document ↗
2 Article 4 directions
Article 4 Basement Development Permitted Rights Removed · Article 4 Direction Class E To C3 In Central Activities Zone. Named permitted development rights are withdrawn here.
An Article 4 direction withdraws particular permitted development rights, so work that would normally need no application needs one here. Not every council has published its directions.
Archaeological priority area: City of Westminster APA 2.6
An assessment or field evaluation may be asked for before ground works.
The council or Historic England considers archaeology likely here. A desk-based assessment, and sometimes trial trenching, can be asked for with the application.
Air quality management area: Westminster AQMA
The council has declared the area as failing an air quality objective.
Schemes that add traffic, parking or combustion plant are assessed against the area's action plan and may need an air quality assessment.
Council record ↗
Central activities zone
The core of central London in the London Plan.
Offices, culture and the other strategic functions of the centre take priority over new housing here.
Also on the record
Scheduled monument 209 m away: A subterranean commercial ice-well (City of Westminster), Park Crescent West, W1; Inside the City of Westminster built-up area.
Not affected
Outside flood zones 2 and 3 · Not green belt

Checked on 25 September 2026. Historic England, the Environment Agency, Natural England and council datasets, Open Government Licence. A boundary can run through a site and the council holds the definitive record: confirm with the council before relying on this.

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Important details

Council
Westminster
Application type
Full Planning Permission Application
Postcode
W1G 6QW
Received
8 Sept 2026
Validated
22 Sept 2026
Ward
Marylebone
Case officer
Show
Target decision
17 Nov 2026
Applicant
Show
Agent
Karl Singporewala + the design bureau

Decision outlook

Day 13 of the 56-day target. Westminster usually decides extensions by day 55.

Day 1343 days to the 56-day target
56%decided within 8 weeks
88%approved
1,672decided in the last year

Plota live figures for extensions decided by Westminster in the last twelve months, from validation. Westminster decision record →

Public comments

No public comments yet.

6 neighbours consulted · Last counted 2 Oct 2026

Read the comments on the council site ↗

Consultation & key dates

Alt. reference
PP-15196115
Comments by
28 Oct 2026
Site or press notice
7 Oct 2026
Env. assessment
No

Historical activity at this location

26 previous applications on record - archival context, not part of the live application.

This property

Previous applications at this address

2020 Approved
Alterations to external glazing to courtyard elevations at lower ground floor
20/01297/FULL
Within ~100m

Nearby activity

2025 Approved
Flat 2 19 Upper Wimpole Street London W1G 6LY
Installation of a new slim double-glazed timber window, painted white within the existing…
25/06205/LBC
2025 Approved
Flat 2 19 Upper Wimpole Street London W1G 6LY
Installation of a new slim double-glazed timber window, painted white within the existing…
25/06204/FULL
2025
93 Harley Street London W1G 6AD
Installation of X2 external signage plaques
25/07419/LBC
2025 Approved
90 Harley Street London W1G 7HS
Replacement of existing plant at second floor roof level and installation of a 1.5m high…
25/05625/LBC
2025 Refused
90 Harley Street London W1G 7HS
Replacement of existing plant at second floor roof level and installation of a 1.5m high…
25/05624/FULL
2025 Refused
15 Upper Wimpole Street London W1G 6LS
Infilling of courtyard between the main house and mews house at basement and ground level…
25/05010/LBC
2025
110 Harley Street London W1G 7JG
Regulation 5 Notice of Intention to Install Fixed Line Broadband Apparatus to a Listed Bu…
25/06888/TELNOT
2025 Approved
99 Harley Street London W1G 6AQ
Repairs and rebuilding of front elevation at second and third floor level including alter…
25/04811/LBC
2025 Withdrawn
99 Harley Street London W1G 6AQ
Repairs and rebuilding of front elevation at second and third floor level including alter…
25/04810/FULL
2025
4 Clarke's Mews London W1G 6QN
Installation of one air conditioning unit at roof level
25/05464/FULL
2025
Ground Floor 35 Weymouth Street London W1G 8BJ
Demolition of existing plant enclosure and part first floor and replacement with new plan…
25/03421/FULL
2025
42 Wimpole Street London W1G 8YF
Internal alterations including strip out various bathrooms, installation of a stud wall t…
25/02216/LBC
2025
12 Upper Wimpole Street London W1G 6LW
Display of a non-illuminated estate agents sign measuring 0.60m x 0.90m attached to the r…
25/01552/AD7
2025
106 Harley Street London W1G 7JE
Installation of seven air conditioning units to rear ground floor level. (Retrospective)…
25/01394/LBC
2025
106 Harley Street London W1G 7JE
Installation of seven air conditioning units to rear ground floor level. (Retrospective)…
25/01393/FULL
2025
113 - 115 Harley Street London W1G 6AP
Installation of replacement steel vent pipe (Linked with 25/01123/FULL).
25/01124/LBC
2025
113 - 115 Harley Street London W1G 6AP
Installation of replacement steel vent pipe (Linked with 25/01124/LBC).
25/01123/FULL
2025
15 Upper Wimpole Street London W1G 6LS
Infilling of courtyard between the main house and mews house at basement and ground level…
25/00869/LBC
2025
15 Upper Wimpole Street London W1G 6LS
Variation of condition 1 of planning permission dated 17 September 2024 (RN:23/07898/FULL…
25/00868/FULL
2024
6 Upper Wimpole Street London W1G 6LG
Extension to the existing basement; replacement of third floor casement rear windows with…
24/06677/FULL
2020 Approved
111 Devonshire Mews South London W1G 6QS
Alterations to increase the height of 6 windows at first floor level, 3 to front elevatio…
20/02179/FULL
2019 Approved
107 Devonshire Mews South London W1G 6QS
Excavation of a basement, including underpinning of existing listed vaults accessed by 10…
19/08533/FULL
2019 Approved
107 Devonshire Mews South London W1G 6QS
Excavation of a basement, including underpinning of existing listed vaults accessed by 10…
19/08529/LBC
2018 Approved
42 Wimpole Street London W1G 8YF
Internal alterations, including replacement of existing open shower on 1st floor with con…
18/10541/LBC
2019 Approved
First Floor Rear 100 Harley Street London W1G 7JA
Internal alterations at rear first floor level.
19/09007/LBC
Westminster
Planning Authority Score
3.5/10
Below average
#221 of 296 councils
Relevant to this application:
Householder decisions

Westminster is slower than most councils at deciding householder applications, ranking #258 out of 296. Only 28% of applications have the time limit extended, well below the 41% national average - the council usually decides on time. Westminster is also one of the strictest councils - it refuses more householder applications than almost any other, with only 81% approved vs 90% nationally.

One of the strictest councils
only 81% approved vs 90% nationally
These figures are council-wide context, not a prediction for this application. View full council performance
Westminster decision statistics
Based on MHCLG data, the year to March 2026
86%
Overall approval rate
Below avg (87%) #201 of 296
81%
Householder approved
Below avg (90%) #277 of 296
44%
Decided in 8 weeks
Below avg (63%) #258 of 296
28%
Extended time limit
Below avg (41%) #46 of 296
83%
Minor dwellings approved
12 decided (1-9 homes)
67%
Major dwellings approved
3 decided (10+ homes)
81%
Change of use approved
133 decided
4,602
Total decisions
648 refused in the year to March 2026
Source: MHCLG planning statistics · See full council rankings