28 Mardley Avenue Welwyn AL6 0TZ

1. 7 Dec 2022

   Received by Welwyn Hatfield

2. 10 Jan 2023

   Validated

   Checked as complete and ready for consideration.

3. 1 Mar 2023

   Decision issued: Granted

4. 9 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.

Householder applications cover work to an existing house and its garden: extensions, loft and garage conversions, porches, outbuildings and similar alterations within the boundary of the home. They cannot be used to create a separate dwelling or change what the building is used for. Councils aim to decide them within eight weeks, and immediate neighbours are usually notified and given a chance to comment.

More on householder applications in our guide

• 2 Woodacre Drive Welwyn AL6 0UA

  6/2026/0974/TPO Submitted 3 Jun 2026 59m away

  T1 Oak Prune western aspect by 2 metres. (Covered by TPO24 A3 and TPO 642 (2017) G1)

  Refused Trees

• 12 Hillside Way Welwyn AL6 0TY

  6/2023/0210/HOUSE Submitted 27 Jan 2023 72m away

  Erection of a two storey rear and side extension with roof alterations including a front dormer and side windows, following the demolition of existing side and rear extensions

  Withdrawn Householder Extension Loft or dormer +3
  Domestic

• 20 Mardley Avenue Welwyn AL6 0UD

  6/2026/1305/TPO Submitted 27 Jul 2026 86m away

  98% historically approved · decision due ~30 Sep

  Up to a 2m reduction to Cherry tree, to maintain its healthy station and prevent over extension, from growing too large. Fell, process and remove Yew tree as resident has concerns that if it was to uproot or fail it would hit the house due to its location (covered by TPO 24 A3)

  Awaiting decision Trees

• 37 Mardley Avenue Welwyn AL6 0TU

  6/2025/2248/FULL Submitted 23 Oct 2025 95m away

  Erection of a single chalet dwelling

  Refused Full applications
  Domestic

• 20 Mardley Heights Welwyn AL6 0SX

  6/2024/1895/TPO Submitted 1 Oct 2024 95m away

  2 x Silver birches branches thinned out. Fell 1 x Hornbeam. (TPO 641 G5 (2017))

  Refused Trees

• 27 Hillside Way Welwyn AL6 0TY

  6/2022/2473/HOUSE Submitted 27 Oct 2022 113m away

  Erection of veranda to the rear of house

  Granted Householder
  Domestic

• 6/2026/1228/HOUSE Granted

  109 Mount Way Welwyn Garden City AL7 4LA

  Erection of single storey front extension

  13 Jul 2026 Householder
• 6/2026/1011/HOUSE Granted

  5 Brookside Crescent Cuffley Potters Bar EN6 4QW

  Erection of rear extension, single storey side extension, new porch, additions/alterations to windows on side elevation and demolition of garage

  9 Jun 2026 Householder
• 6/2026/0703/HOUSE Granted

  57 Great North Road Brookmans Park AL9 6LA

  Erection of part double part single storey rear extension, single storey front porch extension, raising of roof and eaves to accommodate loft conversion, alterations to materials and fenestration, erection of front boundary wall and gates

  20 Apr 2026 Householder
• 6/2026/0534/HOUSE Refused

  16 Chipmunk Chase Hatfield AL10 9GH

  Retention of single storey rear extension and garage conversion to study/office

  24 Mar 2026 Householder
• 6/2026/1175/HOUSE Granted

  5A Honeycroft Welwyn Garden City AL8 6HR

  Erection of a single storey rear extension, alterations to opening on side elevation and garden room with covered area following demolition of conservatory

  7 Jul 2026 Householder