Yes, and with fewer obstacles than almost anywhere else in the district. Hardly anything is listed. There is no conservation area. The neighbours are all extending too. The planning department is not the thing to worry about here. The clay under the garden is.
Historic England lists 7 buildings in Hextable, all Grade II, with none at Grade I or Grade II*. Listing protects a building inside and out, so owners of those 7 need listed building consent for most changes, including some that would not normally count as development. Everyone else is unaffected. In a village of post-war semis and bungalows, the odds of buying one of the protected few are small, and you would know it from the sale paperwork long before the builder turned up.
Between April 2024 and June 2026, 1,286 planning applications were recorded for Hextable and its immediate surroundings, 570 of them in the last twelve months. That is a lot of people deciding the house they bought needs to be bigger. On streets built in one go after the war, every rear extension and loft dormer gives the next neighbour a precedent and a reason to start their own.
The ground is the real constraint. The British Geological Survey's shrink-swell hazard reaches class 3 in parts of Hextable, covering more than a third of postcodes. Clay at that level swells when wet and shrinks when dry, which moves foundations, especially near thirsty trees. For an extension it usually means deeper foundations than a builder's standard quote assumes, and a structural engineer's opinion before the design is fixed. A cheap rear extension on shrinking clay can turn expensive at the foundation stage.
In practice, with no conservation area and so few listed buildings, most homes here keep the usual householder permitted development rights, which allow modest rear extensions and many loft conversions without a full planning application, subject to national size limits and prior approval for some larger projects. Anything bigger, or anything on the front of the house, goes through Sevenoaks District Council in the normal way. Check the original planning permission for your property, because some estates were built with conditions that removed permitted development rights, and finding that out after you have paid an architect is a waste of a fee. The village was laid out from 1870 as a place of large villas, and two of those, Southbank and Newbank on College Road, were demolished for flats and townhouses. Hextable's attitude to its own buildings has always been fairly relaxed.
Freedom to alter your home is one of Hextable's real strengths. The paperwork is light, the precedents are on every street, and the clay underneath is the only thing likely to slow you down.