Welwyn Hatfield Borough Council

Adopted Documents We Assess Against

Development plan: Welwyn Hatfield Local Plan 2016-2036 (adopted 1 October 2023)

Documents are re-checked against the council's own website weekly. A detected change flags "Policy Update Available" for human review — live assessment standards are never replaced automatically.

Welwyn Hatfield Borough Council standards at a glance

1 numeric standards taken from Welwyn Hatfield Borough Council's own adopted documents, each shown with the paragraph it comes from. Figures differ between councils — these are this one's.

Design character

up to 50%

The council generally refuses an extension more than 50% greater than the original building in the Green Belt, measured against footprint, volume AND above-ground external dimensions - so give the LARGEST of the three, and note this is assessed case by case rather than as an absolute cap. Welwyn Hatfield Local Plan (Green Belt extensions) (provisional citation)

Standards are what the council normally expects, not a guarantee. A scheme outside them can still be approved on its merits, and one inside them can still be refused for another reason.

Authored Policy Library

5 local policy checks, each citation-locked to the adopted document. National policy (NPPF, national space and daylight standards) applies alongside these.

Welwyn Hatfield Local Plan 2016-2036

• Welwyn Hatfield Local Plan 2016-2036 (design policies) — Design character (provisional citation) Welwyn Hatfield judge proposals on design and local character. In the Garden City areas especially, established building lines and layout matter - check whether your street has an Article 4 direction or estate character guidance.
• Welwyn Hatfield Local Plan Policy SADM11 — Amenity neighbouring Welwyn Hatfield assess neighbour impact under Policy SADM11. Show the relationship to your neighbours' windows on your drawings.
• Welwyn Hatfield Local Plan paras 24.10 and 24.12 — Design character If your house is in the Green Belt, Welwyn Hatfield will generally refuse anything more than 50% bigger than the original building - measured on footprint, volume and external dimensions. Watch out for outbuildings within 5 metres of the house: they count towards that 50%.
• Welwyn Hatfield Local Plan (Green Belt extensions) — Design character (provisional citation) The council generally refuses an extension more than 50% greater than the original building in the Green Belt, measured against footprint, volume AND above-ground external dimensions - so give the LARGEST of the three, and note this is assessed case by case rather than as an absolute cap.
• Welwyn Hatfield Local Plan 2016-2036, read 2026-08-05 — Rear extension depth Outside the Green Belt, Welwyn Hatfield set no depth or height figures. There is no number to design to - the case turns on design and the effect on neighbours.