A drone survey firm covering Okehampton

Okehampton is about half an hour from the Exeter base on the A30, which by distance makes it one of the easier towns to reach on this list. By flying conditions it is the hardest, and those two facts pull in opposite directions when a date is being set.

Dartmoor forces Atlantic air upwards right on the doorstep, so rainfall is high, driving rain is frequent and roofs stay wet for long periods. This is one of the wettest and windiest towns covered here. In practice that means a date is offered against a forecast, a fallback date is worth agreeing at the same time, and a flight that gets moved is normal rather than a failure. Nobody is charged for a flight that did not happen.

The town centre is granite and slate, with Victorian terraces and a large stock of post-war housing. Beyond it the parishes carry scattered moorland farms and longhouses, with corrugated metal on the farm buildings and granite-bedded ridges on the older stock.

Farm work here is a particular case. A moorland holding may have half a dozen structures spread across a yard, only one of which anybody is worried about, and the sensible instruction is to photograph the lot in a single visit while the aircraft is up. The marginal cost of the extra buildings is small and the value of having them on record before the next winter is not.

Granite-bedded ridges and stone detailing are worth a specific mention because they behave differently to mortar-bedded work. They are heavy, they move slowly, and when they do move it shows as a line rather than a crack. Reading that from a photograph is a matter of knowing what a settled ridge looks like as opposed to a failing one.

In most of the towns on this list the damage worth finding comes from an event: a gale, a blocked outlet, a failed detail. Here the main agent is time. Roofs stay wet for long enough that organic growth, saturated timber and slow decay do more damage than any single storm.

That changes what a useful report says. The findings are less about what broke and more about what is wearing, which makes an interval-based record considerably more valuable than a one-off. A building photographed here two or three years apart shows a direction, and that direction is what a repair budget should be built on.

Being half an hour from base makes that pattern affordable, which is the one respect in which this difficult town is an easy one.

The castle ruins and Meldon Viaduct are a reminder that not everything needing a survey around here is a roof. Historic structures, bridges and disused engineering works come up as instructions in this part of the county, usually for a conservation body or a landowner wanting a condition record of something nobody can climb.

Those jobs are flown the same way and reported the same way, with the same statement of what could not be seen. The high moor beyond, with Yes Tor and High Willhays above the town, is a reminder of how quickly the ground rises here and how fast the weather follows it.