West Sussex · RH19
Extensions in East Grinstead
A home extension adds new floor space to an existing property — commonly a rear or side-return kitchen extension, a wraparound, or a first-floor addition — and typically involves planning or permitted development approval, Building Regulations, and coordination of groundworks, structure, roofing and internal finishing.
In East Grinstead, that covers Ashurst Wood, Forest Row, Dormans Park, West Hoathly, Felbridge, Turners Hill, Imberhorne. East Grinstead's High Street is one of the best-preserved medieval streets in Sussex, lined with timber-framed and Georgian-fronted buildings, while the wider town includes Victorian terraces, 20th-century suburbs and newer estates. The town sits close to Ashdown Forest and the Weald countryside that gives the region its name.

Coverage
Areas we cover in East Grinstead for extensions
Property styles in East Grinstead
The town centre has a concentration of historic timber-framed and listed buildings, while the surrounding residential areas include Victorian and Edwardian terraces, interwar semis, and later estate housing. Extension work in the older core often needs to respect visible timber framing and historic materials.
Planning considerations
Mid Sussex District Council is the local planning authority. East Grinstead High Street and surrounding streets are within a conservation area with numerous listed buildings, so work affecting the exterior of properties here is more tightly controlled than in the newer suburbs. We confirm the position for individual properties during feasibility.
How it works
Our extensions process
- 01
Feasibility and survey
Assessing what is achievable on the plot, including boundary conditions, trees, drainage and neighbouring properties.
- 02
Design
Developing layout and elevations that work with the existing house, in scale and materials.
- 03
Planning route
Establishing whether the extension falls under permitted development or requires a full planning application, and submitting accordingly.
- 04
Party wall matters
Serving party wall notices where the extension is near a boundary, ahead of any groundworks starting.
- 05
Construction
Groundworks, structure, roof, and first fix through to decoration, with the existing house kept weathertight throughout.
- 06
Completion
Building Control sign-off, snagging list and handover.
Also in this area
Other services we provide in East Grinstead
Nearby coverage
Extensions in nearby areas
FAQs
Extensions in East Grinstead: FAQs
Do you provide extensions across all of East Grinstead?
Yes, we cover the RH19 postcode area in full, including Ashurst Wood, Forest Row, Dormans Park, West Hoathly, Felbridge, Turners Hill, Imberhorne.
Do I need planning permission for a rear extension?
Many single-storey rear extensions fall under permitted development if they meet size, height and boundary criteria. Larger extensions, those on designated land, or properties where permitted development rights have been removed, need a full planning application. We assess this during the feasibility stage.
What is a party wall notice and do I need one?
If your extension involves work at or near a shared boundary, the Party Wall etc. Act 1996 usually requires you to notify your neighbour before work starts. We flag this during design so notices can be served in good time.
Can I extend a listed building in East Grinstead town centre?
Listed buildings require listed building consent for alterations that affect their character, in addition to any planning permission needed. We assess this on a case-by-case basis and can advise on the likely process.
Get a quote for extensions in East Grinstead
Tell us about the property and what you have in mind, and we'll arrange a site visit.
Last reviewed 2026-07-19.