23 Thornbury Avenue, Isleworth, TW7 4NF

1. 15 Oct 2025

   Received by Hounslow

2. 20 Jan 2026

   Validated

   Checked as complete and ready for consideration.

3. 13 Feb 2026

   Decision issued: APPROVED

4. 12 Aug 2026

   Added to PlanIndex

Hounslow granted permission on 13 February 2026, subject to any conditions on the decision notice. Work must normally begin within three years or the permission lapses. More in our guide to what happens after a planning decision.

Householder applications cover work to an existing house and its garden, such as extensions, lofts and outbuildings, and cannot create a separate dwelling or change what the building is used for. More in our guide to planning application types.

• 21 Thornbury Avenue, Isleworth, TW7 4NF

  P/2025/2580 Submitted 21 Aug 2025 50 yards away

  Installation of render the front and side elevation and installation of external wall insulation and render to the rear elevation of the house.

  Granted Householder 7 docs
  Domestic

• 31 THORNBURY AVENUE, ISLEWORTH, TW7 4NF

  P/2023/1037 Submitted 31 Mar 2023 50 yards away

  Retrospective application for the erection of a single storey side and part rear extension, roof extension with rear and side dormers and roof windows; changes to front boundary wall, rendering of external walls and replacement windows and doors

  Granted Householder Extension Loft or dormer +1 8 docs
  Small domestic

• 31 THORNBURY AVENUE, ISLEWORTH, TW7 4NF

  P/2023/0164 Submitted 17 Jan 2023 50 yards away

  Retrospective application for the erection of a single storey side and part rear extension, roof extension with rear and side dormers and roof windows; changes to front boundary wall, rendering of external walls and replacement windows and doors.

  Refused Householder Extension Loft or dormer +1 9 docs
  Small domestic

• 24 THORNBURY AVENUE, ISLEWORTH, TW7 4NQ

  P/2021/2046 Submitted 24 May 2021 50 yards away

  Variation of Condition 2 (approved plans) and Condition 3 (no additional windows and doors) to improve the appearance and utility of the extension of planning application 01118/24/P1 approved under appeal dated 30/11/2020 for erection of single storey rear extension and side and rear roof dormer extensions with one front roof window to the house and alteration to fenestration.

  Granted Householder Extension Loft or dormer +1 5 docs
  Small domestic

• 24 THORNBURY AVENUE, ISLEWORTH, TW7 4NQ

  P/2021/3441 Submitted 24 Aug 2021 50 yards away

  Non material amendment for one additional window to the side elevation on the ground floor level following planning permission 01118/24/P1 dated 30/11/202 for erection of single storey rear extension and side and rear roof dormer extensions with one front roof window to the house and alteration to fenestration

  Refused Amendments Extension Loft or dormer +1 3 docs
  Small domestic

• 24 Thornbury Avenue, Isleworth, TW7 4NQ

  P/2025/3152 Submitted 20 Oct 2025 50 yards away

  Change of use from a residential house (C3) to a Large House in Multiple Occupation (Sui Generis).

  Refused Full applications 12 docs

• P/2026/2304 Granted

  18 Clifden Road, Brentford, TW8 0PF

  Erection of a side and rear extensions.

  Received 7 Aug, published by the council 12 Aug 2026 Householder
• P/2026/2804 Awaiting decision

  128 Durham Road, Feltham, TW14 0AE

  Erection of a detached outbuilding in the rear garden following demolition of existing shed.

  Received 2 Oct, published by the council 9 Oct 2026 Householder
• P/2026/2301 Granted

  4 Glebe Street, Chiswick, W4 2BG

  Erection of a front side and rear side infill extensions with alterations to the rear elevation, a rear side first floor infill extension with replacement of windows to the rear elevation and installation of new rooflights to the existing ground floor infill extension of the house

  Received 7 Aug, published by the council 16 Aug 2026 Householder
• P/2026/1167 Granted

  20 Firs Drive, Hounslow, TW5 9TD

  Erection of part one, part two-storey side extension following demolition of existing garage and part one, part two-storey rear extension. Raising of roof ridge, erection of rear roof extensions, and installation of one front roof window.

  Received 15 Apr, published by the council 26 Jul 2026 Householder
• P/2026/2025 Granted

  1 Kneller Gardens, Isleworth, TW7 7NP

  Erection of a single storey rear and first floor side extension incorporating the conversion of the existing garage to a habitable room

  Received 8 Jul, published by the council 26 Jul 2026 Householder