Usually, but not casually, and not on the timetable you have in your head. The area holds 56 listed buildings and a conservation area covering the historic core. Hundreds of planning applications have gone in over the past couple of years, so people plainly do build here. The ground underneath is the highest-hazard band for clay movement. This is a place where extensions happen, and they happen with a consultant attached.
Listing is the first thing to check, because it changes everything about what follows. There are 56 listed buildings in the area, of which 5 are grade one, 1 is grade two star and 50 are grade two. If the house is listed at any grade, listed building consent is required for works affecting its character, inside as well as out. That covers the things owners assume are theirs to decide: windows, internal walls, staircases, fireplaces, roof coverings, and in many cases the choice between lime and cement on the render. Permitted development rights do not rescue a listed building, and unauthorised works to one are a criminal matter rather than a paperwork problem.
Tisbury has one conservation area, covering the historic centre. Inside it, the tests are about the appearance of the place rather than the individual building. Demolition, works to trees and alterations visible from the street draw closer scrutiny, and permitted development rights can be restricted by direction in ways that vary area by area. The practical instruction is the same in every conservation area in the country: confirm with Wiltshire Council what applies to the specific address before assuming a rear extension or a set of replacement windows is a free hit.
There are also 2 scheduled monuments in the area. That is the strictest protection tier in the system, and it matters mainly for land in or near one, where consent comes from a separate national process rather than the council.
The volume of applications says people do get things done. Wiltshire's planning register carries 553 applications across the area from April 2024 to June 2026, with 273 of them in the last twelve months. That is not a village where nobody bothers applying.
The ground is the constraint buyers overlook. The British Geological Survey puts shrink-swell, the seasonal movement of clay soils, at class three across all of the area, its highest recorded class here. That is a published hazard classification rather than a verdict on any particular plot, and its practical consequence is foundation design: deeper footings, attention to nearby trees, and a structural engineer's view before the trench depth gets decided on site. Soluble rocks reach the same class across about 87% of the area, which is another prompt for a proper ground investigation rather than an assumption. None of this stops an extension. It changes what it costs.
So the working answer depends on which house you buy. An unlisted twentieth-century property outside the conservation area sits under the ordinary national permitted development rules, subject to the usual size and siting limits. A listed cottage in the middle of the village is a consent project from the first drawing, and the design will be shaped by the conservation officer's view as much as by the architect's. The whole area also sits inside a nationally protected landscape, which is another layer of design expectation on anything visible and new.
Freedom to alter a home here is middling: real, exercised regularly, and heavily dependent on the address. Check the listing entry, the conservation area boundary and the ground conditions before you fall in love with a plan, because in Tisbury the survey and the consent decide the extension long before the builder does.