17 Grosvenor Street London W1K 4QH Data via plota.co.uk

25/09112/FULL - Full Planning Permission Application Approved

Proposal

Installation of air source heat pump in modified plant enclosure; green roof and rooflights; modifications to front mansard profile and front elevation. Data via plota.co.uk

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View original council record ↗Last checked

Application progress

✓
Received
17 Dec 2025
✓
Consultation
21 Feb 2026
✓
Approved
2 Apr 2026

Approved on 2 Apr 2026 · Delegated Decision · Last checked 3 Oct 2026

Documents 35

Decision & officer reports 2

PDF GRANT OF FULL PP [PE] Decision Notice · 2 Apr 2026 View ↗ PDF DELEGATED REPORT Report · 2 Apr 2026 View ↗

Statements & assessments 1

PDF DESIGN AND ACCESS STATEMENT Design and Access Statement · 17 Dec 2025 View ↗

Plans & drawings 22

PDF LOCATION PLANS Drawing · 17 Dec 2025 View ↗ PDF EXISTING BASEMENT PLAN Drawing · 17 Dec 2025 View ↗ PDF EXISTING GROUND FLOOR PLAN Drawing · 17 Dec 2025 View ↗ PDF EXISTING 1ST FLOOR PLAN Drawing · 17 Dec 2025 View ↗ PDF EXISTING 2ND FLOOR PLAN Drawing · 17 Dec 2025 View ↗ PDF EXISTING 3RD FLOOR PLAN Drawing · 17 Dec 2025 View ↗ PDF EXISTING 4TH FLOOR PLAN Drawing · 17 Dec 2025 View ↗ PDF EXISTING ROOF PLAN Drawing · 17 Dec 2025 View ↗ PDF PROPOSED 3RD FLOOR PLAN Drawing · 17 Dec 2025 View ↗ PDF PROPOSED 4TH FLOOR PLAN Drawing · 17 Dec 2025 View ↗ PDF PROPOSED ROOF PLAN Drawing · 17 Dec 2025 View ↗ PDF EXISTING SECTION AA SOUTH ELEVATION Drawing · 17 Dec 2025 View ↗ PDF EXISTING SECTION BB SOUTH NORTH Drawing · 17 Dec 2025 View ↗ PDF EXISTING SECTION DD NORTH SOUTH Drawing · 17 Dec 2025 View ↗ PDF EXISTING SECTION EE SOUTH NORTH Drawing · 17 Dec 2025 View ↗ PDF EXISTING SECTIONS FF AND GG EAST WEST Drawing · 17 Dec 2025 View ↗ PDF PROPOSED PART SECTION AA SOUTH ELEVATION Drawing · 17 Dec 2025 View ↗ PDF PROPOSED SECTION AA SOUTH ELEVATION Drawing · 17 Dec 2025 View ↗ PDF PROPOSED SECTION BB SOUTH NORTH Drawing · 17 Dec 2025 View ↗ PDF PROPOSED SECTION DD NORTH SOUTH Drawing · 17 Dec 2025 View ↗ PDF PROPOSED SECTION EE SOUTH NORTH Drawing · 17 Dec 2025 View ↗ PDF PROPOSED SECTIONS FF AND GG EAST WEST Drawing · 17 Dec 2025 View ↗

Application forms 1

PDF APPLICATIONFORMREDACTED Application Form · 17 Dec 2025 View ↗

Consultation & comments 1

PDF NEIGHBOUR NOTIFICATION LETTER (21D) Background Papers · 21 Feb 2026 View ↗

Other documents 8

PDF ACK-GENERAL LETTER (G/P/C) Background Papers · 21 Feb 2026 View ↗ PDF CNSLT-LA SOCIETY Background Papers · 21 Feb 2026 View ↗ PDF CNSLT-LA SOCIETY Background Papers · 21 Feb 2026 View ↗ PDF CNSLT-LA SOCIETY Background Papers · 21 Feb 2026 View ↗ PDF SITE NOTICE 21 OR 28 DAYS IF T&C APPL. Background Papers · 21 Feb 2026 View ↗ PDF RECEIPT OF APPLICATION Other · 12 Feb 2026 View ↗ PDF ACOUSTIC REPORT Acoustic report · 17 Dec 2025 View ↗ PDF DOCUMENT ISSUE AND REGISTER Background Papers · 17 Dec 2025 View ↗

All documents on the council site ↗

Associated applications 2

Site constraints 11

Mayfair 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 2.5
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 ↗
Town centre: West End
A designated centre in the London Plan.
Shops, services and active frontages are protected in centres, and main town centre uses are steered here first.
51 listed buildings within 150 m
Nearest: 16, Grosvenor Street W1, Grade II, 6 m away · 1 Grade I, 3 Grade II*, 47 Grade II
The site itself is not listed. 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 all 51 with distances
Historic England ↗
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
National infrastructure project 1287 m away: Thames Tideway Tunnel; Registered park or garden 192 m away: Berkeley Square; Inside the City of Westminster built-up area; Public transport access: PTAL 6b (excellent), TfL 2023, for the 100 m square.
Not affected
Outside flood zones 2 and 3 · Not green belt · No scheduled monument at the site

Checked on 6 October 2026. Historic England, the Environment Agency, Natural England, the Planning Inspectorate, Transport for London (public transport access levels, Powered by TfL Open Data, OGL v3.0, contains OS data © Crown copyright and database right 2025) 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.

Building

Floor area1,182 m² (12,723 sq ft)
Energy ratingC (asset rating 64)
UseB1 Offices and Workshop businesses
HeatingMixed-mode with Natural Ventilation

From the energy performance certificate lodged in July 2017, the latest held for this property. The building may have changed since. View the certificate

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Other new applications on this street

5 Oct 2026Pending

67 - 68 Grosvenor Street London W1K 3JN

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1 Oct 2026Pending

63 Grosvenor Street London W1K 3JG

Display for temporary period of six months of non-illuminated 'to let' board loc...

26/06731/AD7
16 Sept 2026Approved

49 Grosvenor Street London W1K 3HP

Internal alterations and refurbishment.

26/06345/LBC
1 Sept 2026Pending

33 Grosvenor Street London W1K 4QU

Replacement of fire doors.

26/05968/LBC

Nearby new applications

3 Sept 2026Pending

Flat 6 16 Mount Row London W1K 3SE

Installation of a single external air confitioning condenser unit at roof level.

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1 Oct 2026Approved

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2 x London planes (T541 and T517): removal of Massaria infected limbs.

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External alterations including replacement entrance doors, facade and glazing al...

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18 Sept 2026Pending

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5 Oct 2026Pending

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26/06786/ADFULL
2 Oct 2026Pending

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Details of scheme of work in relation to doorway removal, openings blocked up, a...

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Important details

Council
Westminster
Application type
Full Planning Permission Application
Postcode
W1K 4QH
Received
17 Dec 2025
Validated
17 Dec 2025
Ward
West End
Case officer
Show
Target decision
6 Apr 2026
Decision
Application Permitted
Decision date
2 Apr 2026
Decision level
Delegated Decision
Applicant
Show
Agent
COWIE MONTGOMERY ARCHITECTS LLP

How this decision compares

Decided in 106 days from validation, 42 days slower than Westminster's median of 64 for full applications. Approved, as 86% of full applications here are.

40%decided within 8 weeks
86%approved
1,349decided in the last year

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

Public comments

No public comments yet.

30 neighbours consulted · Last counted 3 Oct 2026

Read the comments on the council site ↗

Consultation & key dates

Alt. reference
PP-14569981
Planning Portal ref
PP-14569981
Comments by
25 Mar 2026
Site or press notice
21 Feb 2026
Env. assessment
No

Historical activity at this location

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

This property

Previous applications at this address

2025 Approved
Infill extension at rear 4th floor; erection of a single storey extension at 5th floor wi…
25/01813/FULL
2016 Approved
Demolition of existing fourth floor mansard to the rear and existing lift overrun, remova…
16/06280/FULL
Within ~100m

Nearby activity

2025
Claridges Hotel 47 - 57 Brook Street West End London W1K 4HR
Replacement of shopfronts and balustrades, and facade repair works including replacement…
25/07266/LBC
2025
Claridges Hotel 47 - 57 Brook Street West End London W1K 4HR
Replacement of shopfronts and balustrades, and facade repair works including replacement…
25/07265/FULL
2025
28 Grosvenor Street London W1K 4QR
Demolition and rebuilding of the 4th floor and roof level to create a sunken roof terrace…
25/07048/FULL
2025 Approved
Hermione House 61 Grosvenor Street London W1K 3JE
Removal of stone stairs from the street down into the front lightwell; Removal of flagpol…
25/04608/FULL
2025 Approved
37 Brook Street West End London W1K 4HH
Installation of new signage (Linked to 25/04938/ADV)
25/04666/LBC
2025 Approved
37 Brook Street West End London W1K 4HH
Display of an internally illuminated hanging sign measuring 0.83m x 0.83m. (Linked to 25/…
25/04938/ADV
2025 Approved
21 - 22 Grosvenor Street London W1K 4QJ
Provision of a lead cloaking to the stone cornice above the ground floor on the front ele…
25/03736/LBC
2025
66 Grosvenor Street London W1K 3JH
Relocation of internal AHUs into new joinery; new kitchen joinery; removal of radiators…
25/03189/LBC
2025
66 Grosvenor Street London W1K 3JH
Relocation of internal AHUs into new joinery; new kitchen joinery; removal of radiators…
25/03188/FULL
2025
Avery Court 29F Avery Row W1K 4BA
Replacement of an existing window on the North-East elevation with a door to access the e…
25/03116/FULL
2025
Broadbent House 64 - 65 Grosvenor Street London W1K 3JH
Amendments to fourth floor glazing and installation of glazed doors for use of the existi…
25/02852/FULL
2025
67 - 68 Grosvenor Street London W1K 3JN
External alterations including the installation of a dry riser cabinet within the front l…
25/02652/FULL
2025
26 Grosvenor Street London W1K 4QJ
New terrace at first floor level to rear, increase size of rear terrace at lower ground f…
25/01853/FULL
2025
21 - 22 Grosvenor Street London W1K 4QJ
Repairs and replacements to localised parts of the roof.
25/01661/CLLB
2025
19 Brook's Mews London W1K 4DX
Display of logos and text on two new awnings measuring 3.50m x 1.40m & 5.00m x 1.40m, and…
25/01494/ADV
2025
26 Grosvenor Street London W1K 4QJ
Removal of water tank and existing projecting access enclosure on the roof and creation o…
25/01294/FULL
2024
37 Brook Street Mayfair London W1K 4HH
Display of five externally non illuminated vinyl logos measuring 0.678m x 0.741m to shop…
24/08161/ADV
2024
66 Grosvenor Street London W1K 3JH
Insertion of an opening in the party wall for a new door at ground floor level between 66…
24/06814/LBC
2024
67 - 68 Grosvenor Street London W1K 3JN
Erection of a single storey extension within the central courtyard with a terrace over pa…
24/06813/FULL
2024 Approved
Ground Floor 10 Grosvenor Street London W1K 4QB
Installation of two wall-mounted uplighters at ground floor level.
24/02907/FULL
2018 Approved
41 - 43 Brook Street Mayfair London W1K 4HJ
Internal alterations at all floor levels including internal connections to the adjoining…
18/04973/LBC
2018 Approved
41 - 43 Brook Street Mayfair London W1K 4HJ
Demolition of the upper floors of 48-49 Brook's Mews and erection of building comprising…
18/04972/FULL
2019 Approved
66 Grosvenor Street London W1K 3JL
Installation of air conditioning to first floor main office and ancillary works including…
19/05096/LBC
2019 Approved
66 Grosvenor Street London W1K 3JL
Installation of two air conditioning units at rear first floor terrace level; installatio…
19/05095/FULL
2019 Approved
21-22 Grosvenor Street London W1K 4QJ
Renewal for a temporary period of six months for display of a non-illuminated estate agen…
19/05834/AD7
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

Freehold boundary: © Crown copyright and database rights 2026, HM Land Registry. Polygons © Crown copyright and database rights 2026 Ordnance Survey 100026316. Conditions of use

Energy performance: Energy performance certificates from the Energy Performance of Buildings Register, Ministry of Housing, Communities and Local Government. Contains public sector information licensed under the Open Government Licence v3.0. © Crown copyright 2026.