Drone survey in Dartmouth

Dartmouth is built on ground so steep that the buildings are effectively stacked, and the practical consequence is that one property's roof frequently discharges towards its neighbour rather than into its own garden. That arrangement works until a gutter blocks, at which point the water goes somewhere that belongs to somebody else.

Sorting out that kind of problem needs a view of both roofs at once, which is the single hardest thing to get in this town from ground level. An overhead photograph of the whole arrangement shows where the water is meant to go and where it is actually going, and it is usually the document that ends the disagreement.

The stock around Bayards Cove and the Butterwalk includes exceptional timber-framed and jettied merchant houses, with Georgian and Victorian terraces climbing the hill behind. Lead-lined valleys and gutters are everywhere on the listed buildings, and lead has a long but finite life.

Lead fails at the joints and at the fixings rather than in the middle, and the failure is gradual. A close photograph of a lead-lined valley shows splits, lifted welts and where a patch has been laid over an older repair. That level of detail is what a survey here is for.

There is very little level ground and the streets are narrow, so take off is planned rather than assumed. Often the practical position is a car park, a quay or a garden well above the property.

The river mouth gives good open approaches, and buildings facing the Dart can be photographed from over the water without standing above anybody's roof. The Naval College dominates the skyline and sits within its own arrangements, so flights around that end of the town are planned with particular care.

The river mouth shelters the town from the worst of the open sea, so this is not primarily a storm damage town. It is a damp one. Persistent moisture, shaded slopes that never dry and organic growth in the valleys are what wear a Dartmouth roof out.

That produces slow, expensive failures in listed fabric, and the argument for a periodic record rather than a one-off inspection is stronger here than in most places on this list.

Britannia Royal Naval College dominates the skyline and the town has an active river with ferries and moorings, so flights here are planned with more than the building in mind. That is ordinary planning rather than an obstacle, and it is settled before a date is offered.

For a TQ6 owner the useful consequence is that the arrangement takes a little longer to set up than a job in a quiet inland town. Being asked for a week rather than a morning is normal here and it produces a better result.

The castle and the river mouth mark where exposure changes. Properties near the mouth get weather that the town centre, tucked behind the hill, largely avoids.