34 Portland Place London W1B 1LX

This site has had 2 applications since 2025.

• 25/09186/FULL Awaiting decision

  34 Portland Place London W1B 1LX

  Use of 34 Portland Place primarily as the Ambassador's dwellinghouse, use of 73 New Cavendish Street as a Polish cultural centre and diplomatic premises, and associated alterations and extensions. [Linked to 25/09187/LBC]

  Submitted 19 Dec 2025 Full applications

1. 19 Dec 2025

   Received by Westminster

2. 20 Feb 2026

   Validated

   Checked as complete and ready for consideration.

3. 20 Jul 2026

   Added to PlanIndex

4. Decision

   Awaiting decision

   Decision expected by 17 April 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.

• 25/09186/FULL Awaiting decision

  34 Portland Place London W1B 1LX

  Use of 34 Portland Place primarily as the Ambassador's dwellinghouse, use of 73 New Cavendish Street as a Polish cultural centre and diplomatic premises, and associated alterations and extensions. [Linked to 25/09187/LBC]

  Submitted 19 Dec 2025 Full applications

1 later application on the register refers to this one:

• 25/09186/FULL Awaiting decision

  34 Portland Place London W1B 1LX

  Use of 34 Portland Place primarily as the Ambassador's dwellinghouse, use of 73 New Cavendish Street as a Polish cultural centre and diplomatic premises, and associated alterations and extensions. [Linked to 25/09187/LBC]

  Submitted 19 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.

• 34 Portland Place London W1B 1LX

  25/09186/FULL Submitted 19 Dec 2025 50 yards away

  87% historically approved · decision due ~17 Apr

  Use of 34 Portland Place primarily as the Ambassador's dwellinghouse, use of 73 New Cavendish Street as a Polish cultural centre and diplomatic premises, and associated alterations and extensions. [Linked to 25/09187/LBC]

  Awaiting decision Full applications Extension 31 docs
  Domestic

• L'ecole Internationale Franco-Anglaise 36 Portland Place London W1B 1LS

  25/09231/FULL Submitted 19 Dec 2025 50 yards away

  Removal of reciprocal means of escape shared between 34 Portland Place and 36 Portland Place and implementation of fire upgrades throughout 36 Portland Place to ensure compliance with current building regulations affecting educational institutions within listed buildings. Works incorporate removal of redundant fire escape doors, upgrades to existing door furniture, installation of partitions to create fire separation lobbies, installation of mechanical extract among other minor alterations (Linked to 25/09232/LBC)

  Withdrawn Full applications 28 docs

• 36 Portland Place London W1B 1LS

  13/03998/ADFULL Submitted 2 May 2013 50 yards away

  Submission of details of refuse & recycling storage and a Travel Plan, pursuant to Conditions 9 and 10 of planning permission dated 08 March 2013 (RN: 12/07230)namely details .

  Granted Full applications 5 docs

• L'ecole Internationale Franco-Anglaise 36 Portland Place London W1B 1LS

  25/09232/LBC Submitted 19 Dec 2025 50 yards away

  Removal of reciprocal means of escape shared between 34 Portland Place and 36 Portland Place and implementation of fire upgrades throughout 36 Portland Place to ensure compliance with current building regulations affecting educational institutions within listed buildings. Works incorporate removal of redundant fire escape doors, upgrades to existing door furniture, installation of partitions to create fire separation lobbies, installation of mechanical extract among other minor alterations (Linked to 25/09231/FULL)

  Withdrawn Heritage and listed buildings 29 docs

• Abercorn School 38 Portland Place London W1B 1LS

  26/00352/LBC Submitted 21 Jan 2026 50 yards away

  90% historically approved · decision due ~18 Mar

  Internal alterations to 38 Portland Place throughout to change the use from sui generis (Institutional Use) to Class E office use throughout in connection with removal of link building between 38 Portland Place and 9 Cavendish Mews North at ground, first and second floors, formation of a new rear stair core to main building and new external fire escape stair. New terraces to office space in connection with plant space and the installation of air source heat pumps. Alterations to the front and rear facades of the mews building in connection with internal alterations to create new residential units and new plant space to mews roof level and new terrace spaces all in connection with the change of use of ground to first floors from sui generis (institutional use) and second floor Class E (office use) of 9 Cavendish Mews North to Class C3 residential use to form 3x 1 bedroom flats. (Part of a land swap with 1 Marylebone High Street and Moxon House). (Linked to 26/00351/FULL)

  Awaiting decision Heritage and listed buildings New dwelling 61 docs

• Abercorn School 38 Portland Place London W1B 1LS

  26/00351/FULL Submitted 21 Jan 2026 50 yards away

  87% historically approved · decision due ~18 Mar

  Internal alterations to 38 Portland Place throughout to change the use from sui generis (Institutional Use) to Class E office use throughout in connection with removal of link building between 38 Portland Place and 9 Cavendish Mews North at ground, first and second floors, formation of a new rear stair core to main building and new external fire escape stair. New terraces to office space in connection with plant space and the installation of air source heat pumps. Alterations to the front and rear facades of the mews building in connection with internal alterations to create new residential units and new plant space to mews roof level and new terrace spaces all in connection with the change of use of ground to first floors from sui generis (institutional use) and second floor Class E (office use) of 9 Cavendish Mews North to Class C3 residential use to form 3x 1 bedroom flats. (Part of a land swap with 1 Marylebone High Street and Moxon House). (Linked to 26/00352/LBC)

  Awaiting decision Full applications New dwelling 85 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

  Alterations to internal partitions, door openings, doors and floor finishes.

  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

  Installation of new concrete slab with drainage channels at basement level and new fire surround in B.01.

  Received 15 Sep, published by the council 22 Sep 2026 Heritage and listed buildings
• 26/06318/LBC Awaiting decision

  124 Hamilton Terrace London NW8 9UT

  Replacement of existing first-floor sash windows to the front and rear elevations with traditionally detailed painted timber, slim-profile double-glazed sash windows. (Linked to 26/06317/FULL)

  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