Yes, and almost nothing old stands in your way. The town has three listed buildings. There are no conservation areas. The neighbours put in planning applications as if it were a hobby. The main thing to watch is the protected countryside around the houses, since there's barely any history inside them.
Historic England's list records 3 listed buildings in Hawkinge, all of them Grade II. There are no Grade I or Grade II* buildings at all. Listing means any change that affects a building's character, inside or out, needs listed building consent on top of ordinary planning permission. Unless your house is one of those three, that rule doesn't reach you. There are also no conservation areas in the town, so the extra controls on windows, doors, roofs and demolition that apply in historic streets elsewhere don't apply here. Heritage officers have very little to inspect in a town built mostly within living memory.
The planning register shows how busy the town's builders are. Between April 2024 and June 2026, 438 planning applications were lodged for the area, and 187 of them came in the last twelve months. That's a steady run of loft conversions, side extensions and garages turned into rooms. The register records only that people apply, not whether they succeed, so the volume is a sign of appetite rather than a promise of permission.
In practice, most straightforward extensions start with the ordinary national rules for permitted development, which let many rear extensions, loft conversions and outbuildings go ahead without a full planning application, within limits on size and position. The one difference is that the whole town sits inside the Kent Downs Area of Outstanding Natural Beauty, and protected landscapes can narrow those rights for some kinds of work. Anyone planning something bigger than a modest rear extension should check with Folkestone and Hythe's planning department before paying an architect. On a modern estate, the likelier obstacle is a restrictive covenant in the deeds, so read the title documents as well as the planning rules.
Freedom to alter a home is one of Hawkinge's real strengths. With almost nothing historic to protect, the constraints are the landscape and the neighbours, not the listing officer.