21 Duchess Mews London W1G 9DY

1. 13 Sep 2007

   Received by Westminster

2. 26 Oct 2007

   Validated

   Checked as complete and ready for consideration.

3. 20 Dec 2007

   Decision issued: Application Permitted

4. 29 Jul 2026

   Added to PlanIndex

Westminster granted permission on 20 December 2007, 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.

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.

• 21 Portland Place London W1B 1PY

  20/07208/LBC Submitted 11 Nov 2020 50 yards away

  Replacement of lift and increase the width of the existing lift entrances to enable wheelchair access.

  Granted Heritage and listed buildings 24 docs

• 19 Portland Place London W1B 1PX

  24/05814/ADFULL Submitted 21 Aug 2024 50 yards away

  87% historically approved · decision due ~16 Oct

  Details of welsh slate, junctions of secondary slope to existing slope and top edge termination and specification of conservation rooflight pursuant to Condition 5 of planning permission dated 27 June 2024 (RN23/05916/FULL) (Linked Installation air conditioning units at roof level within plant enclosure; secondary glazing to all windows; replacement of two doors with fire-rated matching doors; and works to fire proof existing doors and the installation of a partition to the existing vault to fire proof a lift motor. (Linked with 24/05961/ADLBC)

  Awaiting decision Full applications Loft or dormer Windows or glazing 8 docs

• 23 Portland Place London W1B 1PZ

  04/07517/FULL Submitted 22 Sep 2004 50 yards away

  Installation of nine air conditioning units at roof level all behind existing louvered screens.

  Granted Full applications 9 docs

• 23 Portland Place London W1B 1PZ

  06/01816/FULL Submitted 8 Mar 2006 50 yards away

  Installation of stone ramp and handrails on the Portland Place entrance. Retention of an air handling unit, relocation of four condensers, removal of redundant chillers and replacement with two new chillers all behind existing dummy mansard screen at roof level.

  Granted Full applications Loft or dormer 13 docs

• 23 Portland Place London W1B 1PZ

  06/01325/FULL Submitted 21 Feb 2006 50 yards away

  Installation of a full height boiler flue within the existing lightwell to roof level.

  Granted Full applications 13 docs

• 23 Portland Place London W1B 1PZ

  04/02771/ADV Submitted 8 Apr 2004 50 yards away

  Display of flagpole and flag.

  Refused Advertising 5 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
• 26/04141/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
• 26/06250/LBC Awaiting decision

  53 Wimpole Street London W1G 8YH

  Removal and Installation of external rear air condensers and associated pipe work to ground floor, including internal works to ground and first floor. (Linked with 26/06249/FULL)

  Received 11 Sep, published by the council 18 Sep 2026 Heritage and listed buildings
• 26/06203/LBC Awaiting decision

  106 Blandford Street London W1U 8AG

  Installation of two roof-mounted anchor posts. (Linked to 26/06202/FULL)

  Received 10 Sep, published by the council 17 Sep 2026 Heritage and listed buildings
• 26/06187/LBC Awaiting decision

  4 Shepherd Market London W1J 7QB

  Installation of wall mounted highway street light on to the facade of 4 Shepherd Market.

  Received 10 Sep, published by the council 17 Sep 2026 Heritage and listed buildings