Are Drones Becoming Essential to Construction?

Drones. They’re not just for military campaigns anymore. Since 2015, the use of unmanned aerial vehicles (UAVs) has exploded in terms of civilian and (non-military) industrial applications. While Gartner suggests that personal drone use is expected to reach 4.6 million units by 2020, Goldman Sachs sees military and civilian drone use becoming a $100 billion market by the same year. 

The overwhelming majority ($70 billion) of UAVs will still be used for making war, with consumer usage capturing another $17 billion, and the rest taken by industrial applications. Of that $17 billion, construction will represent the lion’s share with $11.2 billion. Anyone who has been following new technological developments in the architecture, engineering and construction (AEC) space knows that, yes, drones are becoming a big deal.

Why is that? To learn the answer, we spoke to a number of companies in the AEC industry to learn how this new crop of low-cost, high-tech UAVs is impacting the way we build buildings. 

The Emergence of Civilian Drones

In 1898, Nikola Tesla demonstrated the first example of radio control (R/C), leading to the development of R/C boats and aircraft. The first fully functional R/C airplane is credited to Walter and William Good in 1937.

Though UAVs have been used as unmanned attack vehicles since the 19th century, they were widely used for military target practice. The de Havilland Queen Bee was constructed in 1935 as a target for battleship gunners. The radio controlled, pilotless Queen Bee was dubbed a “drone” after male worker bees, who don’t have stingers or gather nectar and pollen. 

After the 1973 flight of the Israeli Tadiran Mastiff—regarded by military historians to be the first modern battlefield drone for its data-linkage, live video-streaming and endurance-loitering—UAVs increasingly became a standard part of warfare. In the U.S., President George W. Bush relied heavily on the use of drones during the country’s invasions and covert operations in the Middle East and other regions before his successor President Barack Obama further increased dependence on the technology. At this point, military drones have earned a reputation for instilling fear in civilian populations that see them fly overhead. 

As military drones became more sophisticated, the electronics that powered them became smaller and less expensive, leading to the growth of radio-controlled products in the 1960s. As R/C-controlled models grew throughout the end of the 20th century, the first consumer quadcopters showed up as hobbyist kits in the late 1990s and early 2000s. 

The first consumer quadcopter may have been the Keyence Gyrosaucer II E-570, a toy released in 1991 that could hover for about three minutes. However, it was the Draganflyer quad helicopter, a kit released in 1999 that was popular among researchers, that evolved into the consumer drones available on the market today.

In 2010, Parrot released its AR.Drone, which was the first drone to be controlled over Wi-Fi and became the first commercially successful consumer drone. Alongside Parrot was 3D Robotics (3DR), which was founded in 2009 with devices based off of the open-source Ardupilot platform. 

In 2015, 3DR released the Solo, the first quadcopter capable of taking professional quality video through the use of an attached GoPro camera. The next year, DJI released the Phantom 4, which featured computer vision and machine learning, rather than a GPS track, for tracking a person, an animal or an object. 

Drones Enter Construction

The initial drone kit community understood the implications of the technology early on. Drones could be used for everything from capturing aerial videos for marketing applications to spraying, monitoring and irrigating crops. In construction, the technology is particularly valuable for uses such as monitoring site progress and tracking material quantities.

“The two most broad ways of kind of thinking about [how drones are used on a construction site]: understanding construction progress … using drone photos, drone maps and 3D models to map exactly what’s happened on a construction site,” DroneDeploy CEO Mike Winn explained. “The second way is using drones to help with site modeling—understanding the topology of the land before something gets built and bringing that into BIM software as a basis for planning.”

Whereas surveying is traditionally performed using mobile scanning units, such as LiDAR systems from companies like Trimble and Leica, drones make it possible to capture the exterior of a site much more cost-effectively. High-definition video or photos taken by a drone that’s flown over the site can be stitched together into 3D models and 2D maps using software from a number of providers, including 3DR, DroneDeploy and Autodesk.

Tristan Randall, a strategic projects executive for Business Development at Autodesk, explained that such models or maps might be captured daily or biweekly to maintain a general record of what’s happening on site, monitoring the movement of materials or dirt on a site. This monitoring can be made more specific, to actually quantify a given task, such as mapping a stockpile to determine the volume of dirt available on site or that has been removed. 

“We’re seeing a lot different use cases, ranging from things like inspecting wind turbines—which may not involve 3D modeling but just using imagery or video—all the way to mapping huge mining sites, where you actually take that data into one of our design platforms like Civil 3D and InfraWorks and perform quantity take-offs, design new facilities and perform quantitative analyses,” Randall said. 

Jason Nichols, product marketing manager at Kespry, highlighted the use of preconstruction work. “D&T Construction is using drones to verify existing elevations on a job before it begins and track the progress of active earthwork operations,” Nichols said. “Companies like D&T are also improving the safety of field personnel by flying above active operations and can map areas in minutes that would typically take hours. The data results in a high resolution 2D and 3D imagery of the entire site that is used to create an accurate topographic map, and calculate cut/fill quantities for any earthwork activity.”

Hugh McFall, product marketing manager for 3DR, added, “[D]rones are making it possible to perform topographic surveys at least 6X faster and at a fraction of the cost. Regularly collecting data with drones helps construction firms perform ongoing QA/QC on their projects—namely, they can compare as-designed to as-built by overlaying their design files on an orthomosaic created by a drone software platform, and spot issues before they become too difficult or costly to fix. Drones are also helping improve safety on-site. For example, instead of having their field personnel climbing stockpiles and risking slipping and falling, many of our customers use Site Scan to perform these measurements from the sky, while their team is safe on the ground.” 

What’s It Take to Fly a Drone?

Whereas, in the past, the ability to capture data of an entire site would require the use of a helicopter or other vehicle, a drone can now be used for a fraction of the cost. But how easy is it to fly a drone?

DroneDeploy’s Mike Winn pointed out that modern drones don’t require the skills one might think to fly them. In fact, current drones fly autonomously, capturing images at designated control points, though they still require a human to monitor the flight. “Interestingly, in the past few years, the drones have very sophisticated sense and avoid technology. If there’s an object in their flight path, they can avoid it,” Winn said.

Hugh McFall, from 3DR, added that, despite this ease, companies may still need some help in deploying the technology. “That said, there are a few things that any company bringing drones onto their projects needs to consider. Our customer success team, who work directly with engineering and construction firms every day, often advises new customers to ensure they have a dedicated drone pilot who can ‘own’ drone operations and become the resident drone expert within their organization. They need to become Part 107 certified as well, which enables them to fly drones for commercial purposes,” he explained.

Processing Data

Given the $11.2 billion gold mine foretold by Goldman Sachs, it’s no surprise that a number of companies offer their own software solutions. Some may involve a mix of hardware and software, according to Kespry’s Jason Nichols.

“Deploying drones into construction company’s workflow can be a seamless process, but it depends on the drone and software configuration. Certain drone solutions have a mixed fleet of hardware and software and require specialized training to fly and/or process the data,” Nichols noted. “When using a fully integrated, end-to-end solution, these types of complexities are eliminated, giving team members the ability to fly on an as-needed basis with delivery of instant data results.”

For this reason, Kespry attempts to create such an integrated solution (seen above). The entire process, from drone flight to data processing and customized reporting from the field, are all performed automatically. Nichols suggests that Kespry delivers “the highest level of GNSS accuracy with PPK (Post Processed Kinematic) technology,” which makes it possible to obtain “positional accuracies down to 2cm without using multiple control points or flight targets.”

Though DroneDeploy also offers an integrated solution, Winn said that the company’s software works with a variety of third-party software. He estimated that, due in part to the power of DroneDeploy’s engine, the company performs the most drone data processing in the industry, producing the most drone data. 

The software makes it possible to use a mobile phone or tablet to perform measurements of objects within the data captured by the drone, such as the heights of buildings, and apply a CAD overlay to compare models to the as-built structures. Moreover, DroneDeploy recently launched a Live Map tool (seen above) that actually makes drone data accessible and shareable across the cloud in real time, something that other software developers have yet to offer.

Autodesk is a pioneer in the reality capture space, offering its ReCap software (seen below), which can use a series of photos, laser scans or a combination of media to generate point clouds and meshes from physical environments. Naturally, the data captured from drones can be easily integrated into Autodesk’s other software, such as AutoCAD for creating 2D drawings and Revit for 3D models. 

In addition to ReCap, Autodesk has built out its Forge platform. Through access to Autodesk APIs, Autodesk partners, such as 3DR, are able to create apps that integrate directly into Autodesk software.

Tristan Randall, from Autodesk, outlined how, by giving partners access to Autodesk APIs, Forge is meant to enable a much quicker exploitation of drone technology. Different partners can create different apps that take advantage of Autodesk software in unique ways, not just capturing images and video, but providing measureable data for engineering and management decision-making. 

One example of software built on the Forge platform is 3DR’s Site Scan (seen above). Site Scan plans and executes flights and captures data automatically. The information is then uploaded to 3DR’s cloud and ReCap, which process it into 3D point clouds, 3D mesh, 2D maps and digital elevation models (DEMs).

Obstacles to Using Drones in Construction

As with all new technologies that enter a legacy industry, there may be some reticence to the idea of learning novel approaches to performing one’s work. This may be particularly true of something like UAVs, which could seem more like a fad than a potentially crucial tool for the construction industry. 

Jason Nichols, from Kespry, pointed out that there was some hesitancy several years ago, due in part to the quality of drones available at the time. “Drones capable of higher levels of accuracy were expensive and required significant training,” Nichols said. “The next phase of drone development was primarily intended for consumer purposes and lacked the accuracy needed to provide credible insights. The price point was low enough for companies to use the drones to record project progress with images and video. Today, drone technology has advanced far beyond consumer applications in which data is survey-grade accurate. Construction companies have overcome the hesitancy and are seeing the commercial drone as another tool in the toolbox for site survey work.” 

“[C]hallenges to more widespread use of drones in construction is more an issue of people’s acceptance of change and new approaches,” said Chris Harman, PE. Harman is senior engineer in SNC-Lavalin’s Atkins business, a leading design, engineering and project management consultancy.  “A few years ago, I would have told you the main issue was data accuracy or that applications and workflows were too disjointed. Today, as authoring tools and the industry have evolved, I see the pushback coming from designers and clients who do not comprehend the value of drones. As exposure to drone capabilities increases and the need for streamlined workflows continues to rise, I believe drone use will become an integral part of the design and construction process.”

Mike Winn, from DroneDeploy, suggested that those most hesitant about using drones in construction might be the surveying community. After all, UAVs are able to capture much of the exterior of a building, bypassing the need for skilled surveyors and their laser scanning equipment. 

However, Winn sees drones as an opportunity for surveyors to complement their existing skillset by offering new insights. Moreover, even maps and models created with drone data may require official sign-offs from licensed surveyors. Therefore, Winn believes that the drone and surveying communities should work together to enable AEC firms to take advantage of drones for surveying.

Regulating Commercial Drones

The biggest obstacle to drone adoption may be the Federal Aviation Administration (FAA) regulations put into place for drone usage.

Commercial UAVs flight for drones under 55 pounds is regulated under Part 107 of the Federal Aviation Regulations (Part 107), which outlines such requirements as always keeping a drone in unaided sight, flying the drone in daylight or twilight with minimum weather visibility of three miles from the control area, a maximum flying height of 400ft, and a maximum speed of 100mph. Drones must be flown by a pilot certified under Part 107 or by someone under the supervision of someone with that certification.

Given the fact that this rule is used for commercial purposes, its requirements are not unreasonable, but it is one hurdle that businesses must face in order to use the technology on a construction site. Having this rule in place, however, makes understanding what is and isn’t allowed much easier, according to Autodesk’s Tristan Randall.

“We’ve certainly removed many of the barriers that existed prior to the Part 107 rules, which made it very difficult and, honestly, kind of economically unviable in some sense to fly drones on the construction site, simply because each site was treated as a special case and each flight in fact potentially needed to be monitored, reported, etc.,” Randall said. “So, the Part 107 rules have really enabled an explosion in the use of drones on construction sites across the world because the U.S. has set a precedent for the rest of the world to look at these regulations and follow similar guidance.”

Flying Drones at the Airport

Autodesk, 3DR and Atkins learned about these regulations firsthand when working with the City of Atlanta to demolish and expand the North and South parking garage at Hartsfield-Jackson Atlanta International Airport (ATL). Not only did the companies have to qualify under Part 107, but they also had to so in actual Class B airspace at a major commercial airport. As a result, the project was awarded the first FAA clearance for such a flight.

“Currently, it is very difficult to fly near an airport, and you’d be amazed at how much of the urbanized United States is near an airport,” Chris Harman from Atkins said. “Unless we can make it simple to operate drones in controlled airspace, it will be very difficult to see a mass increase in usage on construction sites. However, I am encouraged by the work that the Federal Aviation Administration is doing with programs to streamline this process and see controlled airspace regulation as a critical challenge that needs to be addressed.”

ATL happens to be the busiest airport in the world, with five active runways that run in parallel. To capture the drone data, the project team had to execute in between active flights. On January 10, 2017, the team used 3DR’s Site Scan to perform seven flights over the airport’s parking garage area before uploading the data to 3DR’s cloud server, where they were processed automatically to create 3D point clouds of the site. 

“[B]y using a drone, we could capture over 700 images and cover 40 acres within a half-day time frame at [ATL],” Harman said. “The images were uploaded to a cloud-based program, where they were automatically processed into accurate 3D point clouds to create models. We will use the models to plan the demolition process and organize construction to minimize effects on the airport’s daily activities.”

“It was unique being able to bring in so many different stakeholders to execute on a project,” Randall said. “We really had to coordinate with FAA, with the airport facilities, air traffic control, 3DR and Atkins, the project lead.”

The Future of Drones in Construction

Given the growth predicted by Gartner and Goldman Sachs, what does the future of drones in the AEC industry look like?

Hugh McFall, of 3DR, put an emphasis on the software. “Here at 3DR, we believe that the future of drones in construction isn’t about the drone per se; it’s about the data it collects,” McFall said. “Now that drones can be flown easily and reliably and collect a ton of useful data, the challenge going forward is to best integrate this data seamlessly across an organization and its projects, and making this data accessible to key stakeholders such as owners, subcontractors and more.”

As a software company, Autodesk, too, is focused on what happens to the data. Specifically, the company wants that data dealt with in more automatic and sophisticated ways. This includes automatically extracting insights using machine learning, image analysis and feature recognition.

“Those are the tools that are going to scale the technology up, taking an already robust return on investment and making an indispensable tool for any construction site,” Randall said. “We’re likely 1-2 years away from that happening.”

Chris Harman, from Atkins, was able to provide his insights from the point of view of an engineering firm. In addition to improved software, which will make it possible to capture discrepancies between as-built projects and plans, as well as actual progress versus the project schedule, Harman sees developments occurring as they relate to data. 

“As we focus on data capture and metrics, I think we will see the industry plan and implement projects more efficiently,” Harman said. “In the future, a daily drone flight of a project site may not only provide data to build a model that checks designs against schedules; it could also report on equipment, personnel, means and methods for construction. Data may be scanned by artificially intelligent applications to assess safety or environmental hazards, which will lead to smarter decisions and more efficient project delivery.”

One company that is already implementing deep learning and machine vision in construction is a new startup called Doxel. Because drones only capture the exterior of a project site, Doxel is using a combination of drones and rovers armed with LiDAR scanners and HD cameras to roam the interior of a project at the end of the workday. 

This data is processed by Doxel’s artificial intelligence (AI) software, which cross-references as-built 3D data with BIM models, schedules and project budgets to catch installation errors and track installed quantities to monitor daily progress and expenditures. By providing this data within the span of 12 to 24 hours after work has been performed—rather than four to eight weeks later, as occurs with typical projects that don’t use drones or AI—companies may be able to stay within budget and on schedule with fewer errors. (Read our interview with the CEO of Doxel here.)