An extension in Welwyn Garden City can need two approvals and two fees rather than one. The planning side is decided under the adopted local plan, and a separate Estate Management Scheme consent may also be required for the same work. What you are founding on is not uniform across the town either. We coordinate the structural engineer and the building control application.
The plan and the policy that applies to this town alone
Welwyn Hatfield Borough Council is the local planning authority, and the plan it decides under was adopted on 12 October 2023. That plan, the Welwyn Hatfield Local Plan 2016 to 2036, contains Policy SP 15, titled The Historic Environment of Welwyn Garden City, which applies to the town alone. Policy SP 15 requires all development proposals to demonstrate, through their design and detailing, that they have responded to the key characteristics of a garden city. An extension design here is judged on its detailing, not only on its size and position.
A second consent, with its own fee
The Estate Management Scheme charges separately, on top of planning. Its fee for a major project, meaning an extension to a property, is £43 per square metre, capped at £750. Those fees are charged separately from, and in addition to, any planning application fee for the same work. The scheme is governed by named policies, including EM1 Extensions and Alterations, EM2 Erection of New Buildings, EM3 Works to Trees and Hedgerows and EM4 Hard Surfacing. Budget for both routes from the outset.
What the extension will be founding on
That depends on the neighbourhood, because the mapped superficial deposits change across the town. British Geological Survey mapping records the superficial deposit at Handside Lane and the town centre as the Lowestoft Formation, a diamicton, which is a chalky boulder clay. At Peartree and Beehive it records the Kesgrave Catchment Subgroup, a sand and gravel. At Haldens and at the northern edge of Digswell it records no superficial deposits, placing chalk at or near the surface. Two houses in the town can therefore sit on materially different bearing strata.
How garden city houses have been extended before
There is built precedent to point at. Barleycroft Green was built in 1932 and designed by A W Kenyon. The conservation area appraisal records that its two storey red brick cottages were originally detached, and have since been largely linked up by garage extensions. It notes that the layout and built forms allowed the low extensions to fit in while maintaining the important gaps above. The Peartree appraisal separately records that where modern development has taken place it has largely occurred to the rear, with some, but not many, side extensions to end terraces.
- Architectural drawings and structural engineer coordination
- Wrap-around extensions and infills
- Insulation, airtightness and thermal detailing to regulations
- Brickwork and mortar matched to the existing elevation
- Steel goalpost frames where the rear wall opens up
Trusted House Extensions in Welwyn Garden City
Extensions live or die on sequencing. The design has to satisfy the planning route, and any separate scheme consent, before groundwork starts. The foundation detail then has to match what is actually found in the trench, not only what the mapping suggests. We appoint the structural engineer, build to the calculations issued, and coordinate the building control applications and inspections. We are a contractor, not an architect or a surveyor. The company is fully insured and registered in England, company number 14611254.
- Site left safe and secure at the end of every day
- Waste cleared as we go, not left piled in the garden
- Neighbours given notice before the noisy stages
- Garden levels and access made good where the build meets outside
- Photographs kept at each stage for your records
- Foundation depth set after trial holes, drains and trees are checked