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Planning application

51 Upper Montagu Street London W1H 1FQ

Granted Westminster 25/03874/FULL Full Planning Permission Application

Works: Extension Windows or glazing

Permission granted. Work must normally begin within three years of the decision or the permission lapses.

Proposal

Internal alterations including lowering of the floor level to the lower ground floor; Installation of replacement modern windows with slimline double-glazed units; external alterations to front and rear elevations to reinstate window baskets; installation of an air source heat pump and replacement of existing railings at main roof level; erection of the rear extension at lower ground floor level to include a green roof; and other associated works.

As published by the council, reference 25/03874/FULL

Application record

Reference
25/03874/FULL
Type
Full Planning Permission Application
Status
Decided
Decision
Granted As published: Application Permitted
Received
9 Jun 2025
Validated
9 Jun 2025
Decided
7 Oct 2025
Ward
Marylebone
Decision by
Complex Delegated Decision
Postcode
W1H 1FQ

Site history

Applications at this address on the Westminster register

This site has had 6 applications since 2025: 3 approved, 0 refused.

  • 26/07161/LBC Awaiting decision

    51 Upper Montagu Street London W1H 1FQ

    Internal alterations to include additional floor lowering within the lower ground floor WC to match the consented level of the other rooms.

    Submitted 19 Oct 2026 Heritage and listed buildings
  • 26/06443/ADFULL Awaiting decision

    51 Upper Montagu Street London W1H 1FQ

    Details of Desktop study and Site investigation reports pursuant to partial discharge of Condition 11 (Phase 2 and Phase 3) of planning permission dated 24th October 2025 (RN: 25/03874/FULL).

    Submitted 21 Sep 2026
  • 26/00898/ADFULL Awaiting decision

    51 Upper Montagu Street London W1H 1FQ

    Details of supplementary acoustic report, detailed drawings of all new doors and windows, new first floor balconettes and investigative report of Phase 1 pursuant to condition 5, 7, 8 and 11 (part) of planning permission dated 24 October 2025 (RN: 25/03874/FULL).

    Submitted 12 Feb 2026 Full applications
  • 26/00814/ADLBC Granted

    51 Upper Montagu Street London W1H 1FQ

    Detailed drawings of new doors, new windows including sections and glazing bar profiles, new skirting, and cornices, new fireplace surrounds, new Juliette balconies pursuant to condition 4 of listed building consent dated 28 October 2025 (RN: 25/03875/LBC)

    Decided 7 Apr 2026 Conditions
  • 25/03875/LBC Granted

    51 Upper Montagu Street London W1H 1FQ

    Internal alterations including lowering of the floor level to the lower ground floor; Installation of replacement modern windows with slimline double-glazed units; external alterations to front and rear elevations to reinstate window baskets; installation of an air source heat pump and replacement of existing railings at main roof level; erection of the rear extension at lower ground floor level to include a green roof; and other associated works.

    Decided 6 Oct 2025 Heritage and listed buildings

Timeline

Dates from the published record

  1. 9 Jun 2025

    Received by Westminster

  2. 7 Oct 2025

    Decision issued: Application Permitted

  3. 30 Aug 2026

    Added to PlanIndex

Cases linked to this one on the register

2 later applications on the register refer to this one:

  • 26/06443/ADFULL Awaiting decision

    51 Upper Montagu Street London W1H 1FQ

    Details of Desktop study and Site investigation reports pursuant to partial discharge of Condition 11 (Phase 2 and Phase 3) of planning permission dated 24th October 2025 (RN: 25/03874/FULL).

    Submitted 21 Sep 2026
  • 26/00898/ADFULL Awaiting decision

    51 Upper Montagu Street London W1H 1FQ

    Details of supplementary acoustic report, detailed drawings of all new doors and windows, new first floor balconettes and investigative report of Phase 1 pursuant to condition 5, 7, 8 and 11 (part) of planning permission dated 24 October 2025 (RN: 25/03874/FULL).

    Submitted 12 Feb 2026 Full applications

Who's behind it

Company information only, from the register and Companies House

ADL Planning Pty Ltd Agent, a planning consultancy

105 applications on PlanIndex · across 7 councils · 91% granted

Trade members see everything this firm has filed, how it was decided, and get an email the day it files again.

See their track record

Documents

Plans, drawings, consultee responses and the officer's report

36 documents on file for this application

A planning file usually holds the application form, drawings and site plans, consultee responses, the officer's report and the decision notice.

Watch members (£5 a month) open the document list from here.

Open the documents

What this grant of permission means

Westminster granted permission on 7 October 2025, subject to any conditions on the decision notice. Work must normally begin within three years or the permission lapses. More in our guide to what happens after a planning decision.

About full applications

A full application seeks permission for a complete, detailed proposal in one go, with siting, design, access and landscaping all fixed at this stage. More in our guide to planning application types.

Nearby applications

Within 0.3 miles

  • 51 Upper Montagu Street London W1H 1FQ

    25/03875/LBC Submitted 9 Jun 2025 50 yards away

    Internal alterations including lowering of the floor level to the lower ground floor; Installation of replacement modern windows with slimline double-glazed units; external alterations to front and rear elevations to reinstate window baskets; installation of an air source heat pump and replacement of existing railings at main roof level; erection of the rear extension at lower ground floor level to include a green roof; and other associated works.

    Granted Heritage and listed buildings Extension Windows or glazing 37 docs

  • 53 Upper Montagu Street London W1H 1SE

    25/05778/ADLBC Submitted 14 Aug 2025 50 yards away

    Details of the height and finished appearance of the new openings at ground and second floor levels, and proposed remedial works required to address damp following inspection works pursuant to Condition 2 (parts i and ii) of the listed building consent dated 2 January 2025 (RN: 24/05972/LBC)

    Granted Conditions 8 docs

  • 51 Upper Montagu Street London W1H 1FQ

    26/00898/ADFULL Submitted 12 Feb 2026 50 yards away

    88% historically approved · decision due ~9 Apr

    Details of supplementary acoustic report, detailed drawings of all new doors and windows, new first floor balconettes and investigative report of Phase 1 pursuant to condition 5, 7, 8 and 11 (part) of planning permission dated 24 October 2025 (RN: 25/03874/FULL).

    Awaiting decision Full applications Windows or glazing 11 docs

  • 51 Upper Montagu Street London W1H 1FQ

    26/00814/ADLBC Submitted 11 Feb 2026 50 yards away

    Detailed drawings of new doors, new windows including sections and glazing bar profiles, new skirting, and cornices, new fireplace surrounds, new Juliette balconies pursuant to condition 4 of listed building consent dated 28 October 2025 (RN: 25/03875/LBC)

    Granted Conditions Windows or glazing 12 docs

  • 51 Upper Montagu Street London W1H 1FQ

    26/07161/LBC Submitted 19 Oct 2026 50 yards away

    90% historically approved · decision due ~18 Dec

    Internal alterations to include additional floor lowering within the lower ground floor WC to match the consented level of the other rooms.

    Awaiting decision Heritage and listed buildings

  • 51 Upper Montagu Street London W1H 1FQ

    26/06443/ADFULL Submitted 21 Sep 2026 50 yards away

    89% historically approved · decision due ~16 Nov

    Details of Desktop study and Site investigation reports pursuant to partial discharge of Condition 11 (Phase 2 and Phase 3) of planning permission dated 24th October 2025 (RN: 25/03874/FULL).

    Awaiting decision

In Westminster

  • 26/05984/FULL Decided

    41 Sutherland Street London SW1V 4JX

    Replacement of front, side and rear windows with double glazed timber framed sash windows and replacement of a door with a double glazed timber framed door.

    Received 2 Sep, published by the council 11 Sep 2026 Full applications
  • 26/07224/FULL Awaiting decision

    8 Hinde Street London W1U 3BQ

    Use of the building as an Embassy (sui generis) with reversion to Class E on cessation of occupation by the Government of the United Mexican States. Erection of a flagpole and flag and plaque

    Received 22 Oct, published by the council 26 Oct 2026 Full applications
  • 26/06134/FULL Decided

    Flat 10H Hyde Park Mansions Cabbell Street London NW1 5BG

    Replacement of front and rear second floor level windows with slim-profile double-glazed panels, retaining the existing window and door frames.

    Received 8 Sep, published by the council 15 Sep 2026 Full applications
  • 26/07258/FULL Awaiting decision

    16A Croxley Road London W9 3HL

    Installation of air to air heat pumps to offices and bedrooms.

    Received 22 Oct, published by the council 23 Oct 2026 Full applications
  • 26/07193/FULL Awaiting decision

    98 Victoria Street London SW1E 5JL

    Shopfront alterations. (Linked with 26/07194/ADV)

    Received 21 Oct, published by the council 22 Oct 2026 Full applications