11 Lowndes Square London SW1X 9HB

1. 22 Apr 2026

   Received by Westminster

2. 28 Apr 2026

   Validated

   Checked as complete and ready for consideration.

3. 21 Jul 2026

   Added to PlanIndex

4. Decision

   Awaiting decision

   Decision expected by 23 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 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's median decision took 66 days. More in our guide to how long planning decisions take.

The published feed does not state which type of application this is; the register entry on Westminster's portal will say. Our guide explains the common types.

• 17 William Mews London SW1X 9HF

  26/02952/NMA Submitted 5 May 2026 50 yards away

  93% historically approved · decision due ~7 Jul

  Amendments to planning permission dated 12 June 2025 (RN: 24/07507/FULL) for the erection of a roof extension and alterations to existing front elevation and fenestration. Excavation of a new basement below part existing dwellinghouse.; NAMELY minor amendments to the ground floor front elevation including revisions to the approved window openings, together with associated minor internal reconfiguration works.

  Awaiting decision Amendments Extension Windows or glazing 12 docs
  Domestic

• 17 William Mews London SW1X 9HF

  26/02286/ADFULL Submitted 7 Apr 2026 50 yards away

  87% historically approved · decision due ~2 Jun

  Details of all flood resilient and resistant measures (including finished floor levels) pursuant to condition 4 of planning permission dated 17th June 2025 (RN: 24/07507/FULL).

  Awaiting decision Full applications 5 docs

• 17 William Mews London SW1X 9HF

  26/04409/FULL Submitted 3 Jul 2026 50 yards away

  87% historically approved · decision due ~1 Sep

  Variation of Condition 1 of planning permission dated 12 June 2025 (RN: 24/07507/FULL) for the erection of a roof extension and alterations to existing front elevation and fenestration; excavation of a new basement below part existing dwellinghouse; Namely, amendments to the ground floor windows.

  Decided Full applications Extension Windows or glazing 16 docs
  Domestic

• 43 William Mews London SW1X 9HQ

  25/09117/FULL Submitted 17 Dec 2025 50 yards away

  Erection of an infill extension at ground and first floor rear replacing the existing first floor enclosed balcony and the ground floor undercroft; installation of new rooflight on main roof.

  Granted Full applications Extension Loft or dormer 13 docs

• 25 Kinnerton Street London SW1X 8EA

  26/02928/FULL Submitted 5 May 2026 50 yards away

  87% historically approved · decision due ~30 Jun

  Extensions at rear, roof and basement levels to create 2 x 5 bedroom dwellings at 25 and 27 Kinnerton Street; new rear balconies at second floor level, PV panels, green roofs and associated works. (SITE 25 & 27 Kinnerton Street)

  Awaiting decision Full applications Extension 58 docs

• 23 Lowndes Square London SW1X 9HD

  04/05743/FULL Submitted 23 Jul 2004 100 yards away

  Installation of automatic security gate to an existing opening on front elevation of block No. 25 (site includes 23-25 Lowndes Square).

  Granted Full applications 5 docs