37 Mardley Avenue Welwyn AL6 0TU

1. 23 Oct 2025

   Received by Welwyn Hatfield

2. 14 Nov 2025

   Validated

   Checked as complete and ready for consideration.

3. 15 May 2026

   Decision issued: Refused

4. 9 Aug 2026

   Added to PlanIndex

Welwyn Hatfield refused this application for the reasons on the decision notice; only the applicant can appeal, and refused schemes often return in revised form. More in our guide to what happens after a planning decision.

A full application seeks permission for a complete, detailed proposal in one go, with siting, design, access and landscaping all fixed at this stage. More in our guide to planning application types.

• 20 Mardley Heights Welwyn AL6 0SX

  6/2024/1895/TPO Submitted 1 Oct 2024 50 yards away

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

  Refused Trees

• 5 Mardley Heights Welwyn AL6 0TX

  6/2021/1299/TPO Submitted 22 Apr 2021 50 yards away

  Prune T1 Oak located at the front of property according to the following specifications: • Crown reduction by removing up to 2 meters growth pruning back to suitable growth points to leave a balanced crown Crown clean removing any damaged, diseased and deadwood Prune G1 Various Species, Beech, Berberis and flowering Current located at the front garden according to the following specifications: • Prune back hard garden side back to mainstem of Beech and following line down other species garden side Prune T3 Pine located at the front of property according to the following specifications: • Crown reduction by removing 1.5 meters growth in height pruning back to suitable growth points reduce lateral branches to leave a balanced crown Prune G3 Mixed Hegde located at the Left of driveway according to the following specifications: • Trim back sides and top to leave a tidy formative shaped hedge trimming back hard form driveway without cuasing possible future browning off Prune T1 Beech located at the left rear of house according to the following specifications: • Crown reduction by removing up to 2.5 meters growth pruning back to suitable growth points to leave a balanced crown bring down height enough but not too much as to keep privacy Crown clean removing any damaged, diseased and deadwood

  Granted Trees

• 8 Mardley Heights Welwyn AL6 0TX

  6/2024/1922/TPO Submitted 8 Oct 2024 50 yards away

  Oak tree to reduce by 25% back to previous cuts (TPO 641 (2017))

  Granted Trees

• 10 Mardley Heights Welwyn AL6 0TX

  6/2026/1440/TPO Submitted 17 Aug 2026 50 yards away

  4 x English Oak (Quercus robur), identified as T1, T2, T3 and T4 on the accompanying sketch plan, protected under TPO 641 (2017). Proposed works: Crown reduction of up to 20%; crown thinning of up to 20%; crown lift to approximately 3–4m; removal of epicormic trunkal growth; selective pruning to provide approximately 2m clearance from the dwelling and approximately 1m clearance from overhead lines. Reason for works: Continued periodic arboricultural management of this established group of Oaks, maintaining appropriate clearance from the dwelling and overhead services whilst retaining a balanced, natural canopy and the amenity value of the trees.

  Granted Trees
  Domestic

• 35 Mardley Hill Welwyn AL6 0TT

  6/2021/1099/HOUSE Submitted 6 Apr 2021 100 yards away

  Replacement garage

  Granted Householder
  Domestic

• 28 Mardley Avenue Welwyn AL6 0TZ

  6/2022/2776/HOUSE Submitted 7 Dec 2022 100 yards away

  Erection of single storey part rear extension following the demolition of existing rear conservatory and the continuation of raised patio and partial garage conversion to form larger utility room and ensuite and installation of skylights.

  Granted Householder Extension Demolition
  Small domestic

• 6/2026/1052/FULL Granted

  Unit 3 Woodside Lane Hatfield AL9 6DE

  Retention of an extension to the existing building and the erection of a rear extension following demolition of existing buildings (part retrospective)

  Received 17 Jun, published by the council 24 Jul 2026 Full applications
• 6/2026/1264/FULL Granted

  53 Brookmans Avenue Brookmans Park AL9 7QG

  Erection of dwelling with boundary wall and gates following demolition of existing property

  Received 17 Jul, published by the council 15 Aug 2026 Full applications
• 6/2026/1337/FULL Granted

  Royal Veterinary College Hawkshead Lane North Mymms AL9 7TA

  Relocation of the Transfusion Medicine Vet Pod and associated parking, landscaping and associated works

  Received 30 Jul, published by the council 9 Aug 2026 Full applications
• 6/2026/1689/MAJ Awaiting decision

  Howlands House Howlands Welwyn Garden City AL7 4QJ

  Erection of a single 3 and 4-storey building comprising 44 temporary accommodation homes, staff office and laundry facilities, children's play space, cycle and vehicular parking, associated servicing, plant enclosure, substation, landscaping and external works.

  Received 25 Sep, published by the council 1 Oct 2026 Full applications
• 6/2026/0952/FULL Granted

  18 Fallowfield Welwyn Garden City AL7 1EE

  Retrospective application for change of use from amenity land to residential land to form part hardstanding and part garden land at the front of the property and installation of a drop kerb

  Received 1 Jun, published by the council 24 Jul 2026 Full applications