17 William Mews London SW1X 9HF

This site has had 4 applications since 2025.

• 26/04409/FULL Decided

  17 William Mews London SW1X 9HF

  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.

  Submitted 3 Jul 2026 Full applications
• 26/02952/NMA Awaiting decision

  17 William Mews London SW1X 9HF

  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.

  Submitted 5 May 2026 Amendments
• 26/02286/ADFULL Awaiting decision

  17 William Mews London SW1X 9HF

  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).

  Submitted 7 Apr 2026 Full applications

1. 19 Dec 2025

   Received by Westminster

2. 23 Sep 2026

   Validated

   Checked as complete and ready for consideration.

3. 28 Sep 2026

   Added to PlanIndex

4. 29 Sep 2026

   Decision issued

5. 30 Sep 2026

   Status changed to Decided

   Previously Pending.

Westminster has decided this application; the outcome above is the register's own wording and the decision notice on the council portal carries the detail. More in our guide to what happens after a planning decision.

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

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

  88% 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

• 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

  88% 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

• 11 Lowndes Square London SW1X 9HB

  26/02696/CLLB Submitted 22 Apr 2026 50 yards away

  89% historically approved · decision due ~23 Jun

  External repairs and redecoration to the front and rear elevations; and other associated works at 11-12 Lowndes Square.

  Awaiting decision 5 docs

• 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

• 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