Yes, and the rules are looser than the scenery suggests. Only a handful of buildings are listed. There's no conservation area. The neighbours send in plans all year round. The landscape is protected more than the houses are.
Historic England's register lists 17 buildings in and around Westfield: 1 at Grade I, none at Grade II*, and 16 at Grade II. Listing covers the whole building, inside and out, so changing one of them means listed building consent on top of ordinary planning, and the council will want to see the reasons for every change. Buying one of those 17 means you're looking after the building, not remodelling it. Everyone else is dealing with the ordinary planning system, which in a village of post-war houses and bungalows is where most buyers will find themselves.
The planning figures show that people extend and alter here as a matter of routine. Between March 2024 and June 2026, 368 planning applications were lodged, and 164 of them came in the twelve months to June 2026. That doesn't tell you how many were approved, but it does tell you nobody in Westfield treats their house as finished. In a village where about a fifth of homes are bungalows, the loft is always going to look like wasted space to somebody.
In practice, many modest rear extensions and loft changes can go ahead under permitted development without a full application. There's one catch that sets Westfield apart from a typical suburb: the whole village sits inside the High Weald Area of Outstanding Natural Beauty, and permitted development rights are narrower in protected landscapes. Check with Rother before assuming your plan counts as permitted development, and get a lawful development certificate if there's any doubt. That piece of paper costs much less than taking down a side extension.
For anyone who wants to add space, Westfield is one of the easier villages around: unless you've bought one of the listed few, the constraints protect the view rather than your floor plan.