Construction Firms Are Flying High With Drone Technology

Claire Cameron examines how unmanned aerial vehicles (UAVs) can be used onsite, with construction firms leading the way in drone technology.

In recent years, the use of drones in the construction industry has skyrocketed, with nearly a fifth of firms using flying robots to scope out work and monitor projects.

According to the UK Drone Usage Report 2016, the sector is one of the top five industries leading the way in unmanned aerial vehicles (UAVs), from surveys and site inspections to reducing health and safety risks onsite.

So, why should construction firms use the technology?

While the traditional method of manually surveying a building is still important, it has limitations, according to Paul MacMahon, architectural assistant at rg+p. The immediate benefit of using drones is the ability to obtain otherwise impossible views of buildings, potential development sites, and landscapes.

The multidisciplinary practise surveys rural and inner-city development sites with imagery and data from drones to help with every stage of the construction process, from design to completion.

“The amount of new information that can be acquired from these unique aerial views, up to 120m in the air, enables more thoroughly informed decision-making across all stages of the design and construction process,” explains MacMahon, who holds a Civil Aviation Authority PfAW licence to fly drones.

Drones eliminate the need for cherry pickers, scaffolding, and putting surveyors in danger by working at heights, according to Lee McDougall, director, Geomatics at AHR Building Consultancy. They can also significantly reduce cost, effort, and time by increasing flexibility.

“Previously, if a survey was scheduled for a specific day and the weather was bad, rescheduling was a time-consuming and expensive exercise, whereas with a drone, re-shooting is a very simple procedure,” he says.

“This, in turn, means less disruption and shorter timescales, which can be especially important in environments such as education or residential, where disruptions to teaching schedules and intrusions on residents are greatly reduced.”

Pexhurst, a family-run construction firm with nearly 40 years of experience working on everything from office fit-outs to the restoration of listed buildings, has recently purchased its first drone.

The Hertfordshire-based contractor has invested in a Phantom DJ4 as an onsite experimental exercise, which managing director Martin Vella hopes will reduce the cost of preliminary project work.

He anticipates that the “fairly simple to operate” drone, which includes autopilot features and a return to home button, will add value to his company “by speeding up the entire process, allowing us to get back to clients more quickly on projects, tenders, and feasibility investigations.”

Vella, who has completed extensive stonework packages and external repairs in recent years, says that while the use of a drone would not have changed the quality of the work undertaken and delivered, “in the early survey stages it would have allowed us to turn things around quicker and at lower costs.”

Vella, a member of a flying club affiliated with the British Model Flying Association (BMFA), explains that the flight time of the Phantom DJ4 was an important factor in Pexhurst’s choice.

“This drone has a 28-minute flight time, which is generally long enough to survey the types of sites we work on, and it also provides outstanding high definition imaging.”

The use of drone footage, according to Egg Homes founder Chris Nelson, has been critical to the progress of construction work at the Lake District’s Viver Green – a development of 19 homes that combine contemporary design with the latest energy-efficient technology.

“A drone allowed us to capture the key stages of the development process, which is invaluable when providing updates on the build progress to purchasers, investors, financial institutions, and various stakeholders,” he says.

“It also allowed us to see the building work from angles we wouldn’t normally be able to see and immediately rectify any potential issues or snags.”

Costain, one of the first contractors to use unmanned aerial vehicles (UAVs), recently repaired the storm-damaged Dover sea wall – a high-risk project made safer by the use of drone technology.

To expedite the repair process, the engineering solutions provider used a high-spec Falcon Asctec Trinity UAV to take high-resolution photographs of the permanent rock armour as well as a topography survey.

“We were dealing with a very unstable and damaged sea wall,” says Peter Slater, Costain’s aerial solutions manager.

He explains that the use of a UAV eliminated the need to access dangerous rocks, resulting in less time spent on-site, which was safer, less expensive, and saved time.

“It took a day and a half to survey the entire area with a drone, whereas manually surveying the entire area to the same degree of accuracy would have taken two or three days,” he says.

“We were able to look at the pictures from the safety of the office and produce a 3D model, which could then be matched alongside the design specification by using the drone.” Drones can also significantly reduce carbon emissions by using only a battery-powered unit, according to Slater.

“We calculated that even though we had to drive down to the site, there was still an 80-90 percent reduction in carbon footprint.” Contractors “can expect to save 30-40% cost reductions on a daily basis” by not needing as many workers on site.

As a result, construction firms will be able to “complete more projects and cut across different sectors with the same sized workforce,” according to Slater.

Drone photography, in conjunction with laser scanning, GPS, and 3D modelling, is also being used to survey historic buildings for conservation and maintenance work.

The technology was recently used by AHR Building Consultancy to survey Lichfield Cathedral, a Grade I listed mediaeval building in Staffordshire.

Capturing accurate data of English Gothic architecture using traditional surveying techniques would have taken time, according to MacMahon, who adds that “the decorative nature of most historic buildings means that they involve particularly complex forms.”

In addition, for conservationists who prefer to avoid physical contact, both drones and laser scanning provide non-contact survey methods.

According to McDougall, a 4K drone with a high pixel count was used at Lichfield Cathedral to increase accuracy by allowing the drone to get close to the fabric of the material and minimise shadows.

“The data collected with our technologies is accurate enough to capture not only every stone but also the details of every instance of wear and tear on this remarkable heritage asset.”

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While drone images are sufficient for a condition survey, the real “magic” is in the combinations, according to McDougall, who explains that combining drones, cameras, laser scanning, and GPS produces accurate measurements for 3D models that can be presented to the client.

“We created highly accurate 2D CAD drawings of the floors, elevation, sections, and roof, with a particular focus on obtaining otherwise very difficult to access aerial shots of the Library and Chapter House,” according to Lichfield.

“We were also able to create an intelligent photographic 3D roofscape from the photographs using 3D Point Cloud and Mesh processing software.”

“The resulting models give the client a comprehensive and highly accurate record of the entire building from which to plan repair and maintenance programmes.”

With the construction industry constantly evolving, cost-saving technology such as drones can make work easier and faster, which “can mean the difference between projects going ahead or not,” according to Vella.

Nelson, a big proponent of using and analysing drone footage throughout the build process, believes developers of all sizes will use the technology in the near future, while MacMahon says rg+p is already planning for it to take off.

“We have been preparing with controlled flights, such as in different weather or at different times of day and night, for which we have successfully completed additional training,” he says.

Last Updated on December 30, 2021


Author: Indra Gupta

Indra is an in-house writer with a love of Newcastle United and all things sustainable.

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