Thermal imaging survey in Totnes

Totnes has one of the older building stocks in this network's coverage, a dense medieval and Elizabethan core with slate-hung and jettied frontages, solid wall construction that in places predates the Georgian and Victorian stock found in most other towns here by centuries. Slate hanging on a wall face is itself a thermal detail worth understanding: it was originally a weatherproofing measure rather than an insulating one, so a slate-hung wall can still be losing heat through the masonry behind it even where the hanging itself looks in good order.

Georgian and Victorian streets sit around this older core, and modern estates on the outskirts at Bridgetown and Follaton bring in the familiar cavity-era picture, so as with several other historic South West towns on this site, where a property sits in Totnes gives a strong first steer on what kind of thermal finding is likely.

The town is inland and reasonably sheltered compared with the coastal towns on this list, but the valley holds damp, and the tightly packed historic roofs have many hidden valleys and party-wall abutments that trap debris and moisture in ways that are simply not visible from the street. Those hidden junctions are exactly where thermal bridging tends to concentrate on old, dense terrace construction, because that is where the building fabric changes thickness or direction most abruptly.

For the very steep main street running from the river up to the castle, the gradient itself changes how weather sits on a building, upper properties catching more wind and lower ones sitting in the valley's damper air, which is factored into how a survey across several addresses on the hill is planned and timed.

A dawn flight after a cold, still night is the usual plan, timed to make the most of the valley's damp air holding a clean temperature difference until first light.

For the historic core specifically, flight planning respects the density of the old roofscape and its many hidden valleys, working from a stand-off distance that gives a clear read without needing to work in close among the chimneys and abutments.

The Butterwalk, one of the most photographed stretches of the historic high street, sits among the very oldest slate-hung stock in the town, while the Dartington Hall estate on the edge of Totnes carries a different building history again, a mix of historic estate buildings and later additions that do not follow the pattern of the town centre at all. A survey on an estate property is planned on its own terms, since estate buildings often have a longer and better-documented history of alteration than an ordinary terraced house, which can actually help when interpreting a thermal finding.