Flat 4b Block 4 Portman Mansions Chiltern Street London W1U 6NS

1. 23 Mar 2026

   Received by Westminster

2. 7 Apr 2026

   Validated

   Checked as complete and ready for consideration.

3. 21 Jul 2026

   Added to PlanIndex

4. Decision

   Awaiting decision

   Decision expected by 2 June 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.

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.

• Flat 4a Block 4 Portman Mansions Chiltern Street London W1U 6NS

  25/06866/TCA Submitted 24 Sep 2025 50 yards away

  2 x Shrub/Trees ? Reduce in height and lateral spread by 1-2 metres ? back to previous.

  Withdrawn Trees 6 docs

• 6 Porter Street London W1U 6DD

  10/01180/ADFULL Submitted 12 Feb 2010 50 yards away

  Details of sample of the proposed stonework material pursuant to Condition 2 of planning permission dated 28 July 2009 (RN:09/03735).

  Granted Full applications 2 docs

• 6 Porter Street London W1U 6DD

  09/09802/ADFULL Submitted 4 Dec 2009 50 yards away

  Details of sample of the proposed stonework material pursuant to Condition 2 of planning permission dated 28 July 2009 (RN:09/03735).

  Refused Full applications 2 docs

• 6 Porter Street London W1U 6DD

  09/08791/ADFULL Submitted 28 Oct 2009 50 yards away

  Approval of details pursuant to Condition 1 of planning permission dated 28 July 2009 (RN:09/03735); namely detailed drawings of new entrance.

  Granted Full applications 3 docs

• Flat 1D Block 1 Portman Mansions Chiltern Street London W1U 5AJ

  25/05866/FULL Submitted 19 Aug 2025 50 yards away

  Replacement of existing single-glazed timber sash and casement windows with double-glazed timber sash and casement windows to match the existing style and opening type. Existing window frames to be retained with no changes to the structural openings.

  Refused Full applications Windows or glazing 13 docs

• Flat 1D Block 1 Portman Mansions Chiltern Street London W1U 5AJ

  25/08576/FULL Submitted 24 Nov 2025 50 yards away

  Replacement of single glazed timber sash and casement windows with double glazed timber windows at ground floor level.

  Granted Full applications Windows or glazing 11 docs

• 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