Extension and planning drawings in Hatfield and Welwyn Garden City

Why are these two towns different from the rest of Hertfordshire?

Welwyn Garden City was founded in 1920 as the second garden city, and Hatfield was designated as a new town after the Second World War. Both were planned, not grown, so streets, plot sizes and house types are often consistent across whole neighbourhoods.

In Welwyn Garden City, many houses are in a neo-Georgian style with brick, tiled roofs and sash-style windows. In Hatfield, there are post-war terraces and semis, plus the older streets and buildings of Old Hatfield.

What is the estate management scheme?

Parts of Welwyn Garden City are covered by an estate management scheme, which exists to protect the character of the original garden city design. Where it applies, it can mean you need separate permission for changes to the outside of your house, beyond planning permission and Building Regulations approval. Whether your street is covered, and what the scheme requires, should be checked at the start, before drawings are produced.

Which council decides?

Welwyn Hatfield Borough Council is the local planning authority for AL7, AL8 and AL10. It decides planning applications, and council building control can check work against the Building Regulations, or you can use a registered building control approver. Parts of the town centre and some residential areas are conservation areas, which limits what counts as permitted development.

What projects come up most?

• uniform garden city houses where a rear extension must keep the look of the street
• post-war semis and terraces with garages that are ripe for conversion
• loft conversions, where the roof form or a conservation area decides whether a dormer is possible

Hatfield's university means many houses near it are let to groups. An Article 4 direction covers houses in multiple occupation in Hatfield, so turning a family house into a small one needs planning permission there. If you plan to extend a let house, tell the designer, because shared use brings extra fire safety duties.

What about neighbours?

Terraces and semis share walls, so a loft or side extension may need a party wall notice. Shared drains and sewers also run behind many houses, and a build-over agreement is needed if you build above a public sewer.

How do I start?

Send your postcode, the type of house and the project, and say whether you know if your street falls within the estate management scheme. With your consent, we pass the enquiry to a architectural designer, if one covers your postcode. If nobody does, we tell you and your details are not shared.