9 Calder Avenue Brookmans Park Hatfield AL9 7AH

1. 31 Mar 2021

   Received by Welwyn Hatfield

2. 5 Jul 2021

   Decision issued: Granted

3. 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

• 6 Calder Avenue Brookmans Park AL9 7AQ

  6/2021/1496/HOUSE Submitted 11 May 2021 59m away

  Erection of single storey side extension, garage, front canopy and first floor rear extension.

  Granted Householder Extension
  Small domestic

• 73 Mymms Drive Brookmans Park AL9 7AA

  6/2026/0525/FULL Submitted 23 Mar 2026 102m away

  Erection of a new dwelling following demolition of the existing building

  Refused Full applications New dwelling Demolition
  Domestic

• 55 Mymms Drive Brookmans Park AL9 7AE

  6/2022/2827/HOUSE Submitted 14 Dec 2022 114m away

  Erection of rear conservatory

  Granted Householder Extension
  Small domestic

• 47 Georges Wood Road Hatfield AL9 7BX

  6/2021/1248/LAWP Submitted 19 Apr 2021 132m away

  Certificate of lawfulness for garage conversion with pitched roof, replacing conservatory flat roof to pitched roof and insertion of roof lights into pitched roof across the garage and conservatory.

  Granted Lawful development Extension Loft or dormer 4 docs

• 54 Georges Wood Road Brookmans Park AL9 7BU

  6/2026/0588/HOUSE Submitted 2 Apr 2026 162m away

  Erection of a single storey rear extension, main roof raised by 1 meter in height and rear dormer with rooflights to facilitate a loft conversion

  Granted Householder Extension Loft or dormer
  Small domestic

• 42 Georges Wood Road Hatfield AL9 7BT

  6/2024/2381/TPO Submitted 13 Dec 2024 194m away

  Fell 1 x uprooted Turkish Oak and 1 x English Oak following storm damage. Covered by TPO 1054 (2023) W1

  Granted Trees

• 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