Yes, usually, unless you bought the old bit. Listed buildings are few, and most sit in the historic cores. Four conservation areas cover those cores. The neighbours put in applications all year round. The heritage rules bite in the old centre, and the clay bites everywhere.
Sturry has 80 listed buildings. Four are Grade I, three are Grade II* and 73 are Grade II. Listing covers the whole building, inside and out, so changes to windows, walls, roofs or layout generally need listed building consent on top of any planning permission. Grade I and II* are the top tiers, and the bar for altering them is higher again. For owners of those 80 buildings, "a small extension" is a phrase that tends to meet the conservation officer before it meets the builder.
There are four conservation areas: Sturry, Fordwich, Westbere No 1 and Westbere No 2. Inside them, the council takes a closer interest in anything visible from the street, and some works that would be automatic elsewhere need an application. Demolition, front extensions and alterations to character features are where owners most often find the rules are stricter than they assumed. Check whether a house sits inside a boundary before planning anything, not after the architect has drawn it.
The planning register shows how keen residents are to change their homes. Between April 2024 and June 2026 there were 828 planning applications across the area, with 342 of them in the last twelve months. In a village this size that's a steady stream of loft conversions, rear extensions and people discovering what their neighbours will object to. It proves people do extend here. It says nothing about which applications got approved, so don't read the volume as a promise.
Mining is a minor issue here. About 2% of postcodes have a recorded mine working within 500 metres, none sits directly over one, and the nearest recorded working to any postcode is about 153 metres away. Hersden, part of the wider area covered here, was built as a coal-mining village, which is why the question comes up at all. In practice that means a mining search during conveyancing, and occasionally a specialist report if a lender or insurer asks for one. It isn't a statement about subsidence.
The ground is the bigger constraint for extensions. The British Geological Survey places the area in shrink-swell class 3, and about 96% of postcodes reach that class. Shrink-swell ground expands when wet and contracts when dry, so it affects foundation depth, drainage and how near to plant trees. For an extension, that means a structural engineer's view on foundations before anyone quotes a price, and possibly deeper footings than a builder would dig on firmer ground. Buyers who skip the engineer to save a few hundred pounds usually spend it on the builder later.
For most of Sturry's post-war semis, bungalows and detached houses outside the conservation areas, modest rear extensions and loft conversions may fall under permitted development, which needs no full planning application within set limits. Listed buildings, homes inside conservation areas, and anything larger or visible from the street are where formal consent comes in. Confirm with Canterbury City Council's planning team before committing: permitted development rights can be removed on individual estates and properties, and only the council's records will say.
Your freedom to extend in Sturry is middling. The heritage rules stay mostly inside the old centre, but the ground under the rest of the village asks for proper foundations wherever you build.