Thermal imaging survey in Tavistock

Tavistock's centre is a actually unusual thing in this coverage area: a coherently planned Victorian town built in green Hurdwick stone on the back of mining wealth, alongside Georgian survivals and, in the surrounding villages, terraced miners' cottages that were built quickly and to a lower standard than the grand civic buildings at the centre. All of it is solid wall, no cavity anywhere in the historic stock, and the stone itself carries its own thermal character, similar in principle to the granite at Okehampton but with its own local behaviour worth reading rather than assuming.

Modern estates on the fringes bring the town's newest housing closer to a standard cavity picture, and the contrast between a miner's cottage in a surrounding village and a modern fringe estate house is about as wide a thermal spread as any single area page on this site covers.

Tavistock sits in the Tavy valley on the western edge of Dartmoor, and the town is very wet, with the moor to the east and the prevailing south-westerly bringing rain up the Tamar valley from the west as well. Steep sites and the town's tall stone chimneys mean wind loading and driving rain both work harder on the upper parts of these buildings than a simple valley-floor exposure would suggest, and a wet stone wall on a steep site here rarely gets a long chance to dry between spells.

For the miners' cottages specifically, thinner and less generously specified than the civic Hurdwick stone buildings, that persistent damp is a real factor in how much heat the wall is losing on any given day, and the report reads that dampness alongside the temperature pattern rather than ignoring it.

A thermal survey on Tavistock's stone stock is planned around a settled dry spell where possible, given how wet this valley runs, and a dawn flight after a cold, clear night gives the clearest comparison between the town centre stone, the outlying miners' cottages and the modern fringe estates.

The Cornwall and West Devon Mining World Heritage Site designation covering parts of the area is factored into flight planning the same way any sensitive heritage boundary would be.

The Pannier Market and the Tavistock Abbey remains sit at the heart of the planned Victorian centre, and properties immediately around them share the same Hurdwick stone construction as the wider town, while housing along the River Tavy itself sits lower and damper, closer to the valley floor's persistent wetness than the streets climbing away from the water. A survey on a riverside property is planned with that extra dampness in mind, since a stone wall that rarely dries between spells reads differently on camera to the same stone a little further up the valley side.