Usually yes, but not without someone in a planning office having an opinion first. The village has been a conservation area since 1990, designated for its architectural and historic interest with the explicit aim of preventing development that changes its character. A handful of homes are listed outright. The surrounding parish is dotted with protected prehistoric monuments. None of that stops extensions happening, and plenty are happening, but the far west of Cornwall is not where you get to guess what the rules are.
There are 30 listed buildings in the area. One carries a Grade I listing, the highest tier, none are Grade II star, and the remaining 29 are Grade II. Listing applies to the whole building, inside and out, and to anything attached to it, which means windows, doors, internal walls, roof coverings, chimneys and render all become matters for listed building consent rather than for personal taste. Granite and slate are expensive to work with and listed granite and slate are more so. Anyone buying one of these 30 should price the consent process and the specialist trades into the purchase, not into the optimism afterwards.
The St Buryan conservation area covers the village itself, designated in 1990 to protect its character. Inside it, the calculation changes even for unlisted houses. Conservation area status typically pulls in extra controls over demolition, over work to trees, and over the visible external details that add up to how a street looks. The practical version is that the front of your house is a shared concern and the back of it is more your own.
Three scheduled monuments sit in the immediate area, and the wider parish is unusually dense with prehistoric sites. Scheduled monument protection is the strictest tier in the system, and it bites on land rather than buildings, so it matters most to anyone planning groundworks, outbuildings or a new access on a plot near one. Digging a foundation in this parish has a non-trivial chance of meeting something older than the church.
Against all that, the live evidence is that people alter their homes here constantly. Cornwall Council's planning register records 493 applications across the area between April 2024 and June 2026, including 199 in the last twelve months. That is not a village where applications are pointless, and it is not a village where people have given up asking. It is a village where asking is the normal first step.
In practice, the split is straightforward. An unlisted house outside the conservation area has the usual permitted development freedoms for a modest rear extension or a loft conversion, subject to the standard national limits. An unlisted house inside the conservation area keeps some of those freedoms and loses others, particularly where the work is visible from the road. A listed building has effectively none of them and needs consent for work that would be invisible elsewhere. The first call is to Cornwall Council's planning team with the address, before the architect and well before the builder.
Freedom to alter a home here is middling: the listings are few enough that most buyers will never touch one, but the conservation area covers the village core, the monuments cover the ground around it, and the honest expectation is a planning conversation rather than a free hand.