13 Arnold Crescent, Isleworth, TW7 7NS

1. 24 Nov 2025

   Received by Hounslow

2. 19 Jan 2026

   Decision issued: GRANT

3. 12 Aug 2026

   Added to PlanIndex

Permission has been granted, usually subject to conditions listed on the decision notice, some of which must be discharged before work starts. The decision notice on the council portal sets out exactly what was approved.

Work must normally begin within three years of the decision or the permission lapses. Neighbours cannot appeal a grant; challenging one means judicial review of how the decision was made, within tight time limits.

A lawful development certificate is a legal determination, not a planning judgement. It asks the council to confirm either that existing use or works are lawful, often through the passage of time, or that a proposal would not need planning permission at all. The applicant must prove the facts; the merits of the scheme are not considered.

More on lawful development applications in our guide

• 11 Arnold Crescent, Isleworth, TW7 7NS

  PA/2025/3346 Submitted 7 Nov 2025 9m away

  Ground floor rear extension 4.50 metres deep, maximum height 3.00 metres, 3.00 metres high to the eaves.

  Granted Prior approval Extension 7 docs

• 22 Arnold Crescent, Isleworth, TW7 7NT

  P/2026/1966 Submitted 2 Jul 2026 44m away

  Erection of a two storey side extension and single storey rear extension.

  Granted Householder Extension 13 docs
  Small domestic

• 6 ARNOLD CRESCENT, ISLEWORTH, TW7 7NT

  PA/2021/2662 Submitted 29 Jun 2021 52m away

  Ground floor rear extension 6 metres deep, maximum height of 2.95 metres, 2.80 metres high to the eaves

  Granted Prior approval Extension 9 docs

• 26 Arnold Crescent, Isleworth, TW7 7NT

  P/2026/1787 Submitted 16 Jun 2026 53m away

  Erection of a single storey rear infill extension and replacement of garage door to window at the front of the house.

  Granted Householder Extension Windows or glazing 6 docs
  Small domestic

• 23 ARNOLD CRESCENT, ISLEWORTH, TW7 7NS

  P/2023/0064 Submitted 3 Jan 2023 54m away

  Erection of a part single, part two storey rear extension and two storey side extension following the demolition of the existing garage

  Granted Householder Extension Demolition 16 docs
  Domestic

• 36 Arnold Crescent, Isleworth, TW7 7NT

  P/2025/2813 Submitted 18 Sep 2025 64m away

  Retrospective application for a single storey rear extension to the house

  Granted Householder Extension 9 docs
  Small domestic

• P/2026/2033 Granted

  3 Benedict Drive, Feltham, TW14 8JH

  Certificate of lawfulness for the proposed erection of a rear roof extension with hip to gable conversion with windows to the front and side of the house.

  8 Jul 2026 Lawful development
• P/2026/2027 Granted

  115 Northumberland Crescent, Feltham, TW14 9SP

  Certificate of lawfulness for the proposed erection of a rear roof extension and windows to the front of the house.

  8 Jul 2026 Lawful development
• P/2026/2009 Granted

  3 Brainton Avenue, Feltham, TW14 0AZ

  Certificate of lawfulness for the proposed erection of a rear roof extension and Juliette balcony with front roof windows to the house.

  7 Jul 2026 Lawful development
• P/2026/2014 Granted

  82 Sussex Avenue, Isleworth, TW7 6LB

  Certificate of lawfulness for the proposed erection of a rear roof extension, a porch to the front of the house, and a front roof window.

  7 Jul 2026 Lawful development
• P/2026/2473 Awaiting decision

  16 Somerset Waye, Hounslow, TW5 9HG

  Certificate of lawfulness for the proposed erection of a rear roof extension with two roof windows to the front and alterations to the existing side roof from flat roof to pitched roof.

  1 Sep 2026 Lawful development