Yes, and with less paperwork than most buyers expect. There are seven listed buildings in the whole place. There are no conservation areas. The neighbours put in applications constantly. Coxheath's history is in the history books, not on the planning file for your house.
Historic England lists seven buildings in Coxheath, all of them Grade II. There are no Grade I buildings and no Grade II* buildings. Listing covers the whole building, inside and out, and any work that affects its character needs listed building consent on top of any planning permission. Replacing windows, knocking through walls or rendering over brick all count. If the house you're viewing is one of the seven, budget for a heritage consultant and a lot of patience. If it isn't, the listing regime won't touch you. There are no conservation areas and no scheduled monuments in the area either, so the stricter rules that cover whole streets in older villages don't apply.
People alter their homes here all the time. The planning register records 2,315 applications between April 2024 and June 2026, and 975 in the last twelve months. That doesn't cover whether they were approved, and nobody should read an approval rate into it. It does show that side extensions, loft conversions and garage conversions are routine here. The kitchen extension is practically a rite of passage.
In practice, most homes here are post-war semis and detached houses with none of those designations, so many modest extensions, loft conversions and outbuildings may fall under permitted development, which needs no full planning application. Permitted development still has size limits, and previous owners may have used some of them up, or conditions on the original estate permission may have removed them. Check with Maidstone's planning department before you commit, and ask the sellers for any certificates of lawfulness and previous consents. The building you're buying may be ordinary. Its planning history might not be.
Freedom to extend is one of Coxheath's strengths. Unless you buy one of the seven listed buildings, your plans depend on the rules for ordinary houses, and those are usually manageable.