56 Upper Montagu Street London W1H 1SN

This site has had 2 applications since 2025.

• 25/09343/LBC 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 25/09342/FULL)

  Submitted 24 Dec 2025 Heritage and listed buildings

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 91 days over the applications it decided in the last year.

• 25/09343/LBC 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 25/09342/FULL)

  Submitted 24 Dec 2025 Heritage and listed buildings

1 later application on the register refers to this one:

• 25/09343/LBC 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 25/09342/FULL)

  Submitted 24 Dec 2025 Heritage and listed buildings

This application is with Westminster for determination, against a statutory target of eight weeks. Over the last year Westminster decided full applications in a median of 119 days. More in our guide to how long planning decisions take.

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.

• 56 Upper Montagu Street London W1H 1SN

  25/09343/LBC Submitted 24 Dec 2025 50 yards away

  90% 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 25/09342/FULL)

  Awaiting decision Heritage and listed buildings New dwelling Loft or dormer +2 21 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

• 13 Thornton Place London W1H 1FL

  26/07219/FULL Submitted 21 Oct 2026 50 yards away

  88% historically approved · decision due ~17 Dec

  Installation of an air conditioning condenser unit to the main roof

  Awaiting decision Full applications

• 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

• 26/07528/FULL Awaiting decision

  69 Eaton Place London SW1X 8DF

  Installation of new cast iron water pipe on rear courtyard elevation. (Linked with 26/07529/LBC)

  Received 5 Nov, published by the council 6 Nov 2026 Full applications
• 26/05200/FULL Decided

  1 The Court House 165 Seymour Place London W1H 4PU

  Installation of waterproofing system to the existing lead flat roofs

  Received 3 Aug, published by the council 28 Aug 2026 Full applications
• 26/07521/FULL Awaiting decision

  Flat 18 Harlequin Court 20 Tavistock Street London WC2E 7NZ

  Installation of one external condenser unit

  Received 4 Nov, published by the council 6 Nov 2026 Full applications
• 26/07508/FULL Awaiting decision

  Buckingham Palace The Mall London SW1A 1AA

  Replacement of existing security lighting to the Buckingham Palace Forecourt with 80 compact LED spotlights installed within the lantern clusters across 10 principal piers, with associated concealed cabling and reversible fixings. (Linked with 26/07509/LBC)

  Received 4 Nov, published by the council 5 Nov 2026 Full applications
• 26/07472/FULL Awaiting decision

  Flat 3 82 New Cavendish Street London W1G 9TA

  Replacement windows to second floor level with vacuum, double glazing windows. (Linked with 26/07473/LBC)

  Received 3 Nov, published by the council 6 Nov 2026 Full applications