56 Upper Montagu Street London W1H 1SN

This site has had 2 applications since 2025.

• 25/09342/FULL Awaiting decision

  56 Upper Montagu Street London W1H 1SN

  Use of ground floor and mezzanine levels to rear as residential (Class C3) use; deconversion of ground floor and mezzanine levels to rear together with two studio flats and one one-bedroom flat to form one three-bedroom maisonette; creation of reconfigured office unit in basement; replacement of all but one window with slimline timber double glazed units installation of secondary glazing to one window; renovation of shopfront; reinstatement of glazed fanlight with opening vent, new solid panel door, and awning; new glazed doors to south elevation of mezzanine garden room; new metal balustrading across rear boundary and raised terrace surface level with walk-on roof lights; replacement of concrete roof tiles with slate and new glazed roof light/ roof access; creation of green roof above mezzanine garden room; removal of modern partition walls and reinstatement of historical plan form as far as possible; reinstatement of historic period features all in connection with the use of building as office at part basement level with the remainder of the building being used as a single residential unit (Class C3) and associated internal alterations. (Linked to 25/09343/LBC)

  Submitted 24 Dec 2025 Full applications

1. 24 Dec 2025

   Received by Westminster

2. 20 Jul 2026

   Added to PlanIndex

3. Decision

   Awaiting decision

   Decision expected by 18 February 2026, 8 weeks from validation under the statutory target for most applications. Extensions of time are common and are agreed case by case.

   Westminster took a median of 66 days over the applications it decided in the last year.

• 25/09342/FULL Awaiting decision

  56 Upper Montagu Street London W1H 1SN

  Use of ground floor and mezzanine levels to rear as residential (Class C3) use; deconversion of ground floor and mezzanine levels to rear together with two studio flats and one one-bedroom flat to form one three-bedroom maisonette; creation of reconfigured office unit in basement; replacement of all but one window with slimline timber double glazed units installation of secondary glazing to one window; renovation of shopfront; reinstatement of glazed fanlight with opening vent, new solid panel door, and awning; new glazed doors to south elevation of mezzanine garden room; new metal balustrading across rear boundary and raised terrace surface level with walk-on roof lights; replacement of concrete roof tiles with slate and new glazed roof light/ roof access; creation of green roof above mezzanine garden room; removal of modern partition walls and reinstatement of historical plan form as far as possible; reinstatement of historic period features all in connection with the use of building as office at part basement level with the remainder of the building being used as a single residential unit (Class C3) and associated internal alterations. (Linked to 25/09343/LBC)

  Submitted 24 Dec 2025 Full applications

1 later application on the register refers to this one:

• 25/09342/FULL Awaiting decision

  56 Upper Montagu Street London W1H 1SN

  Use of ground floor and mezzanine levels to rear as residential (Class C3) use; deconversion of ground floor and mezzanine levels to rear together with two studio flats and one one-bedroom flat to form one three-bedroom maisonette; creation of reconfigured office unit in basement; replacement of all but one window with slimline timber double glazed units installation of secondary glazing to one window; renovation of shopfront; reinstatement of glazed fanlight with opening vent, new solid panel door, and awning; new glazed doors to south elevation of mezzanine garden room; new metal balustrading across rear boundary and raised terrace surface level with walk-on roof lights; replacement of concrete roof tiles with slate and new glazed roof light/ roof access; creation of green roof above mezzanine garden room; removal of modern partition walls and reinstatement of historical plan form as far as possible; reinstatement of historic period features all in connection with the use of building as office at part basement level with the remainder of the building being used as a single residential unit (Class C3) and associated internal alterations. (Linked to 25/09343/LBC)

  Submitted 24 Dec 2025 Full applications

This application is with Westminster for determination, against a statutory target of eight weeks. Over the last year Westminster decided heritage and listed building applications in a median of 94 days. More in our guide to how long planning decisions take.

Listed building consent is needed for works that affect the special interest of a listed building, and carrying out such works without it is a criminal offence. More in our guide to planning application types.

• 56 Upper Montagu Street London W1H 1SN

  25/09342/FULL Submitted 24 Dec 2025 50 yards away

  87% historically approved · decision due ~18 Feb

  Use of ground floor and mezzanine levels to rear as residential (Class C3) use; deconversion of ground floor and mezzanine levels to rear together with two studio flats and one one-bedroom flat to form one three-bedroom maisonette; creation of reconfigured office unit in basement; replacement of all but one window with slimline timber double glazed units installation of secondary glazing to one window; renovation of shopfront; reinstatement of glazed fanlight with opening vent, new solid panel door, and awning; new glazed doors to south elevation of mezzanine garden room; new metal balustrading across rear boundary and raised terrace surface level with walk-on roof lights; replacement of concrete roof tiles with slate and new glazed roof light/ roof access; creation of green roof above mezzanine garden room; removal of modern partition walls and reinstatement of historical plan form as far as possible; reinstatement of historic period features all in connection with the use of building as office at part basement level with the remainder of the building being used as a single residential unit (Class C3) and associated internal alterations. (Linked to 25/09343/LBC)

  Awaiting decision Full applications New dwelling Loft or dormer +2 24 docs

• 13 Salisbury Place London W1H 1FJ

  25/07187/ADFULL Submitted 6 Oct 2025 50 yards away

  Details of secure by design accreditation pursuant to Condition 10 of planning permission dated 27th March 2025 (RN: 23/08920/FULL).

  Granted Full applications 4 docs

• 51 Upper Montagu Street London W1H 1FQ

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

  87% 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

  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

• 51 Upper Montagu Street London W1H 1FQ

  25/03874/FULL 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 Full applications Extension Windows or glazing 36 docs

• 26/04878/LBC Decided

  34 Grosvenor Street London W1K 4QU

  Internal works to facilitate the subdivision of 34 Grosvenor Street and 3 Three Kings Yard

  Received 21 Jul, published by the council 1 Aug 2026 Heritage and listed buildings
• 26/06299/LBC Awaiting decision

  Apartment 33 24 Park Crescent London W1B 1AA

  Removal of non structural partitions, replacement of non original doors with full height concealed doors.

  Received 15 Sep, published by the council 22 Sep 2026 Heritage and listed buildings
• 26/06305/LBC Awaiting decision

  33A Dean Street London W1D 4PP

  Waterproofing the basement level.

  Received 15 Sep, published by the council 22 Sep 2026 Heritage and listed buildings
• 26/04141/LBC Decided

  80E Randolph Avenue London W9 1BG

  Replacement of sashes in two front windows at 2nd floor level and one rear window with slimline double glazed timber sashes. (Linked with 26/04142/FULL)

  Received 23 Jun, published by the council 21 Jul 2026 Heritage and listed buildings
• 26/06288/LBC Awaiting decision

  Barness Court 6 - 8 Westbourne Terrace London W2 3UW

  Installation of a new riser as per GW10 design comprising a single riser with 7 entries and 9 Taylor valves to be installed. (Linked with 26/06287/FULL)

  Received 14 Sep, published by the council 21 Sep 2026 Heritage and listed buildings