Mar. 24 2020

Drones are revolutionizing the way inspections of buildings and structures are done – particularly those that are hard to access. Bureau Veritas drone expert Valentin Giraud talks us through this emerging field.

From pylons and towers to rooftops, tanks and confined spaces, drones are a game-changing; new tool for materials experts and inspectors. Drones’ ability to reach great heights and maneuver very tight spaces offers significant safety benefits.

Although they can sometimes be seen as mere gadgets in the eyes of the masses, for inspection, control professionals, drones are so much more. They serve as an extra pair of eyes for inspectors, thanks to their ability to access tight spaces and raised structures quickly. Meeting with Valentin Giraud, drone expert at Bureau Veritas.


An acoustics expert by training – and it was in this capacity that he was first recruited by Bureau Veritas in 2014 in France – he followed his heart, and transitioned into the aviation sector. ”As a private jet and drone pilot, in 2018 I reached out to Bureau Veritas to suggest I put my skills to work in the safety business, a sector that is one of the company’s main areas of expertise.”

Drones boast a range of benefits when it comes to inspection. Drawing on their cameras and photogrammetry features (i.e. a technique in which 3D models can be created from 2D images), drones allow users to produce digital models of buildings. And when used in on-site inspections, drones offer an additional helping hand for human inspectors.


As an example, Valentin Giraud points to the process involved in inspecting a cable-car that links two French ski resorts. Every fifteen years, an in-depth inspection is conducted on the cable-car's structure. Until now, this slow, fastidious process had been reliant on rope technicians and meticulous risk management to inspect all twelve sides of the four towers holding the cable-car up, several dozen meters above the ground. This year, a drone was used for the very first time: ”Thanks to the drone, all twelve sides were inspected in just five and a half hours. In that time, the rope technicians would only have completed one or two sides.”

When it comes to inspecting tanks, meanwhile, small drones can be used to access structures, where previously an inspector would have had to have been lowered in.

Drone inspection relies on two experts working together in perfect unison: remote pilots cannot leave their devices unattended. The drones require continuous surveillance, meaning that remote pilots are always supported by a technical expert tasked with checking and viewing the inspected structures on-screen in real-time.

”When we inspected the cable-car towers, for example, the diagnostic technician (a concrete structure specialist) wore a virtual reality headset that allowed him to see what the drone was filming live. I kept my eye on the sides, and as soon as the technician spotted something, he asked me to zoom in to inspect the detail more closely and to take a photo. It's a real two-man job.”


More and more companies today are offering drone-based photography services, yet few of them combine this technical process with proven inspection expertise, complete with detailed feedback and action plans to be implemented immediately by the client: which is exactly what Bureau Veritas does. The aim is to supply a detailed inspection report without delay, in which defects are clearly highlighted.

”This is a new technique,” explains Valentin Giraud. ”It's still evolving, developing and maturing to better meet our clients' needs, demands and priorities. New drone-based services will soon be emerging”. It's still early days for drone inspection. But this technique is one to look out for.