53 Upper Montagu Street London W1H 1SE

1. 14 Aug 2025

   Received by Westminster

2. 1 Sep 2025

   Decision issued: Application Permitted

3. 21 Jul 2026

   Added to PlanIndex

Westminster granted permission on 1 September 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.

This application deals with conditions on an existing permission, supplying the details a condition requires or asking to vary or remove one, without reopening the permission itself. More in our guide to planning application types.

• 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

• 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

• 57A Upper Montagu Street London W1H 1SG

  26/00135/LBC Submitted 12 Jan 2026 50 yards away

  90% historically approved · decision due ~1 Apr

  Replacement of two windows on the rear elevation with timber double-glazed sash windows.

  Awaiting decision Heritage and listed buildings Windows or glazing 14 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

• 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

• 26/04860/ADLBC Granted

  New Zealand House 80 Haymarket London SW1Y 4TE

  Details of external and internal signage strategy pursuant to Condition 7(E) of listed building consent dated 12th February 2021 (RN: 19/07816/LBC)

  Received 20 Jul, published by the council 1 Aug 2026 Conditions
• 26/04843/ADLBC Granted

  New Zealand House 80 Haymarket London SW1Y 4TE

  Detailed design and specification of new blinds to NZH based on mock-up trials on-site pursuant to Condition 6(m) of listed building consent dated 12th February 2021 (19/07816/LBC).

  Received 20 Jul, published by the council 1 Aug 2026 Conditions
• 26/05026/ADLBC Awaiting decision

  St James's Park The Mall London SW1A 1AA

  Details of method statement for re-carving works pursuant to condition 3(i) of listed building consent dated 16 July 2026 (RN: 26/03399/LBC)

  Received 27 Jul, published by the council 4 Aug 2026 Conditions
• 26/04850/ADLBC Awaiting decision

  17 Belgrave Square London SW1X 8PG

  Detailed drawings of garage doors, roof lantern and any new lighting and flooring in the principal rooms pursuant to condition 6 (iii) (iv) (v) of listed building 18th August 2025 (RN:25/03417/LBC)

  Received 20 Jul, published by the council 1 Aug 2026 Conditions
• 25/07120/ADLBC Granted

  72 - 74 Lancaster Gate London W2 3NH

  Details of new and altered doors and door architraves, including external faces of lifts (detailed elevations and sections at 1:10) pursuant to Condition 3 (A) of Listed Building Consent dated 14 December 2023 (RN: 23/00772/LBC) (Linked app: 25/07088/ADFULL)

  Received 2 Oct, published by the council 21 Jul 2026 Conditions