20 - 21 Cavendish Square London W1G 0RN

This site has had 3 applications since 2026.

• 26/03509/FULL Awaiting decision

  20 - 21 Cavendish Square London W1G 0RN

  Installation of replacement roof top plant with a dummy mansard roof extension, replacement plant at ground floor and new third floor roof structure and new substation at the lower ground floor. [Linked to 26/03510/LBC]

  Submitted 28 May 2026 Full applications
• 26/03232/ADV Awaiting decision

  20 - 21 Cavendish Square London W1G 0RN

  Display of a flag measuring 2.15m x 1.12m.

  Submitted 15 May 2026 Advertising

1. 28 May 2026

   Received by Westminster

2. 21 Jul 2026

   Added to PlanIndex

3. Decision

   Awaiting decision

   Decision expected by 23 July 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.

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.

• 20 - 21 Cavendish Square London W1G 0RN

  26/03232/ADV Submitted 15 May 2026 50 yards away

  84% historically approved · decision due ~10 Jul

  Display of a flag measuring 2.15m x 1.12m.

  Awaiting decision Advertising 7 docs

• 20 - 21 Cavendish Square London W1G 0RN

  26/03509/FULL Submitted 28 May 2026 50 yards away

  87% historically approved · decision due ~23 Jul

  Installation of replacement roof top plant with a dummy mansard roof extension, replacement plant at ground floor and new third floor roof structure and new substation at the lower ground floor. [Linked to 26/03510/LBC]

  Awaiting decision Full applications Extension Loft or dormer +1 28 docs

• Payphone Site Outside 1 Old Cavendish Street London W1G 0NE

  12/01065/ADV Submitted 6 Feb 2012 50 yards away

  Single sided vinyl advert measuring 646mm x 1770mm attached to one glazed face of each of two conjoined payphones located outside 1 Old Cavendish Street (West of 'John Lewis' department store)

  Refused Advertising Windows or glazing 10 docs

• Cavendish House 18 Cavendish Square London W1G 0PJ

  25/06186/LBC Submitted 1 Sep 2025 50 yards away

  Removal of double doorway with surrounding frame and glazing, provision of matwell, refurbishment of C20th and C21st elements.

  Granted Heritage and listed buildings Windows or glazing 19 docs

• Underground Car Park Cavendish Square London W1G 0PG

  26/02623/NMA Submitted 21 Apr 2026 50 yards away

  Amendments to planning permission dated 24th May 2022 (RN 19/08460/FULL) for: Demolition and erection of above ground structures in conjunction with the use of an underground car park (Sui Generis) as a flexible mixed use commercial development comprising uses within the following use classes A1-A5, B1,B2, B8, C1, C2, D1, and D2 along with the excavation of a 4th basement level, new entrances and associated landscaping and highways works to provide up to 25,953 sqm (GIA) of floorspace NAMELY, design refinements to Level 04, the South East Pavilion (lifting pavilion), the South West Lift and the North Pavilions.

  Granted Amendments Demolition 53 docs

• Flanders House 1A Cavendish Square London W1G 0PH

  26/04900/LBC Submitted 22 Jul 2026 100 yards away

  90% historically approved · decision due ~16 Sep

  Maintenance and repair works to the external elevations of the building including ironwork and windows.

  Decided Heritage and listed buildings Windows or glazing

• 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