Yes, and plenty of people are already doing it. The town carries 236 listed buildings. Six scheduled monuments sit in and around it. Not one conservation area covers the place. The constraint here is not a blanket thrown over whole streets, it is a scatter of individually protected buildings, and whether it lands on you is decided entirely by your address.
The listing register is the thing to check first. Of the 236 listed buildings in the area, 4 are grade one, 6 are grade two star and 226 are grade two. Grade two is the ordinary tier and it is not an ornamental designation: listing covers the whole building, inside as well as out, and consent is needed for changes that affect its character. That catches the work people assume is theirs to do without asking, which is windows, internal walls, chimneys, roof coverings and anything that alters the shape. Permitted development rights, the ones that let most homeowners build a modest rear extension without a formal application, do not apply in the way owners expect once a building is listed.
The six scheduled monuments are a different and stricter tier again, and they protect the ground rather than the building. They include Tiverton Castle and Cranmore Castle, the Iron Age hill fort above the town, along with Roman military sites. Scheduled monument consent is a separate process from planning permission and it applies to digging as much as to building, so this matters mainly to anyone whose land sits within or hard against one of those areas.
None of this stops the town altering itself. Mid Devon District Council's planning record shows 766 applications across the area between April 2024 and June 2026, with 344 of those in the last twelve months. That is a steady stream of householders, developers and owners of protected buildings all putting drawings in front of the same committee, which tells you the system here is used rather than avoided.
Practically, the split is simple enough to work out before you offer on anything. An unlisted house outside any designated area is subject to the ordinary national permitted development rules, which cover a good deal of what most buyers want to do, with a formal application needed once the work goes beyond them. A listed building is a different project with a different budget, a longer timetable and a specialist on the payroll. The absence of a conservation area is the genuine relief in all this, because area-wide designations are what usually catch the owners of perfectly ordinary houses who happen to live on the wrong street.
Your freedom to alter a home here sits below average for a town this size, weighed down by the number of protected buildings rather than by blanket area rules. Check the listing register against the specific address before you start drawing anything, because in Tiverton the answer changes house by house.