Through the spring and summer of 2020, a condition survey that would normally start with a ladder, a cherry picker or a scaffold had a new problem: limits on how many people could be on site, and owners reluctant to let anyone into their building. Yet roofs still leaked and planned maintenance budgets still had to be set. Drone inspection solved much of it.
What a drone survey can show
A drone can photograph a roof, chimney stacks, parapets, gutters and high level elevations in detail, in a fraction of the time and cost of access equipment, without anyone leaving the ground. For a block of flats or a listed building, that means the condition of the parts nobody normally sees can be recorded, graded and costed. The images also stay on file, so the next survey can be compared like for like.
What it cannot do
A drone records what it sees. It cannot lift a slate, test a timber or feel whether a coping is loose. Good practice is to use the drone to find and record, and to target close inspection where the images show a problem. That is consistent with the RICS guidance note Surveying assets in the built environment, which centres on agreeing the scope of an inspection with the client and reporting within it.
The rules
From 31 December 2020 new UK drone rules were due to apply, sorting flights into categories according to risk and requiring remote pilots to show their competence. Operators and pilots have had to register with the Civil Aviation Authority since 30 November 2019, and commercial flying close to people and buildings in towns needs a permission from the CAA, not just registration. Before commissioning a drone survey, ask who is flying, what permissions they hold, and how the flight will be planned around residents and neighbours.
Where it fits
We use drone inspection within our building surveys and planned maintenance work. For a recent example, see how a Grade II listed building’s ten year plan drew on drone images of its dome and lantern.