Yes, you can extend in Pewsey, but expect to ask permission more often than you would elsewhere. Most homes aren't listed. Parts of the village are in conservation areas, though. The whole of Pewsey sits in protected downland. And the neighbours submit planning applications at a steady rate, which shows it can be done.
The area has 53 listed buildings: one Grade I, none at Grade II*, and 52 Grade II. For those homes, listing covers the whole building, inside and out, so replacing windows, removing a wall or adding a rear extension all need listed building consent on top of any planning permission. Those buyers who find this out after exchange are the ones telling the neighbours that the conservation officer ruined their kitchen. The other homes in Pewsey don't carry listed status, though they don't escape the other layers of protection.
Three conservation areas fall within the area: Pewsey, Pewsey Wilcot Road and Fyfield. Inside them, the council has more say over changes to the outside of a house, particularly anything visible from the street, and demolition needs consent. The entire area also sits in the North Wessex Downs Area of Outstanding Natural Beauty. A protected landscape narrows what the planners will wave through, so a design that would pass without comment in a suburb can get closer scrutiny here.
The neighbours are going ahead with changes anyway. Wiltshire's planning records show 356 applications in the area between April 2024 and June 2026, and 157 of those in the last twelve months. That's steady proof that people alter homes here. The volume tells you people are applying, not how many applications succeed, so don't let a neighbour's scaffolding persuade you your own plans are certain.
In practice, how much you can do depends on the address. A house outside the conservation areas and not listed may be able to use permitted development rights for some smaller changes. A listed home, or one inside a conservation area, will need consent for more of the work. The protected landscape can narrow what counts as permitted development even outside those boundaries. Before you buy a house for the extension you plan to add, check its listing status, confirm whether it's inside a conservation boundary, and ask the council what needs permission at that specific address.
Your freedom to extend in Pewsey is middling. Most of the village can be improved, provided you get permission first, and anyone who wants to start building before they apply will find more room in a less protected place.