Yes, but the village gets an opinion first. Most homes aren't listed. The centre is a conservation area. The neighbours file plans all the time. The rule here is simple: extend by all means, just expect to explain yourself.
Rotherfield has 31 listed buildings. One is Grade I, none are Grade II*, and the other 30 are Grade II. Listing covers the whole building, inside and out, so changes that would be routine elsewhere, from windows to internal walls, need listed building consent on top of any planning permission. Thirty-one is a small share of the village's homes, which means most buyers won't own one. The ones who do will learn that owning a piece of history mostly means asking permission to change a hinge.
There is 1 conservation area, covering the centre of Rotherfield. Inside it, the council takes a closer interest in anything that changes how a building looks from the street, and demolition, some extensions and work to trees all come under tighter control than in an ordinary suburb. The whole village also sits inside the High Weald Area of Outstanding Natural Beauty, a designation planners take into account when judging how a proposal fits the landscape. Neither makes extending impossible. Both make the design conversation longer.
The planning records show people are not deterred. The area logged 841 applications between April 2024 and June 2026, and 324 of them came in the last twelve months. That is a village full of householders drawing up plans for kitchens, garden rooms and loft conversions, and planning officers reading them. Whatever the rules say, nobody here has taken them as a reason to stop improving the house.
In practice, a house outside the conservation area and not listed has the most room to move, and some smaller works may fall under permitted development without a full application. Inside the conservation area, assume the options are narrower and check before commissioning drawings. For a listed building, assume nothing is permitted until the council says it is. A pre-application conversation with Wealden's planners costs less than a redesign, and a lot less than a refusal.
Freedom to extend here is middling: most of the village can build with ordinary care, while the conservation core and its listed buildings reward patience rather than ambition. Buy the unlisted house on the edge if the plans are big; buy the one in the centre if the plans are mostly paint.