Theresa Arevalo was in high school when she first tried finishing drywall at her brother’s construction company. “It’s a fine art,” she says of mudding—applying and smoothing drywall. “Like frosting a cake, you have to give the illusion that the wall is flat.”
Fast-forward a few decades: Arevalo now works at Canvas, a company that’s built a robot using artificial intelligence that’s capable of drywalling with almost as much artistry as a skilled human worker.
The robot has been deployed, under Arevalo’s supervision, at several construction sites in recent months, including the new Harvey Milk Terminal at San Francisco International Airport and an office building connected to the Chase Center arena in San Francisco.
About the size of a kitchen stove, the four-wheeled robot navigates an unfinished building carrying laser scanners and a robotic arm fitted to a vertical platform. When placed in a room, the robot scans the unfinished walls using lidar, then gets to work smoothing the surface before applying a near perfect layer of drywall compound; sensors help it steer clear of human workers.
The Canvas robot can help companies do more drywalling in less time. It requires human oversight, but its operator does not need to be an expert drywaller or roboticist.
It has long been impractical to deploy robots at construction sites, because the environment is so varied, complex, and changing. In the past few years however, advances including low-cost laser sensors, cheaper robotic arms and grippers, and open source software for navigation and computer vision have made it possible to automate and analyze more construction.
The more advanced machines marching onto construction sites will help make construction less wasteful. According to McKinsey, productivity in construction has improved less than in any other industry over the past couple of decades. The arrival of more automation may also alter demand for labor in a number of building trades.
Kevin Albert, cofounder and CEO of Canvas, previously worked at Boston Dynamics, a company famous for its lifelike walking robots, and in the manufacturing industry. He says there’s great opportunity in construction, which generates about $1.4 trillion annually and accounts for around 7 percent of US GDP but has seen relatively little use of computerization and automation. “We really see construction as mobile manufacturing,” he says. “There's this natural extension of what machines are now capable of out in the real world.”
Canvas is part of a boom in construction technology, says Alex Schreyer, director of the Building and Construction Technology Program at the University of Massachusetts, Amherst. He says some of the biggest progress is being made in prefabrication of buildings, using robotic processes to construct large parts of buildings that are then assembled on-site. But increasingly, he says, robots and AI are also finding their way onto conventional work sites.
Autonomous vehicles made by Volvo ferry materials and tools around some large sites. Technology from San Francisco startup Built Robotics lets construction machinery such as diggers and dozers operate autonomously. A growing array of robotic equipment can take over specialized construction tasks including welding, drilling, and brick-laying. “There are some really interesting things happening,” Schreyer says.
An IDC report published in January 2020 forecasts that demand for construction robots will grow about 25 percent annually through 2023.
One big opportunity in construction, Schreyer says, is using computer vision and other sensing technologies to track the movement of materials and workers around a work site. Software can automatically flag if a job is falling behind, or if something has been installed in the wrong place. “There is so much potential to do something with that using AI,” Schreyer says. “More companies are going to move into that AI space.”
Doxel, based in Redwood City, California, makes a mobile robot that scans work sites in 3- so that software can calculate how the project is progressing. A four-legged Boston Dynamics robot called Spot is being tested for the same purpose at a number of sites. Several companies sell drones for automated construction site inspection, including Propeller, vHive, ABJ Drones, and DJI.
Buildots, based in Tel Aviv, Israel, sells software that uses cameras fitted to the helmets of site managers, which automatically capture a site and process the images to identify discrepancies between plans and ongoing work. The technology is being used on several large European construction projects.
Roy Danon, Buildots’ cofounder and CEO, says the goal is to use the data collected from work sites to help companies design buildings and plan construction schedules better. “We believe we can have a huge impact on planning,” he says, “if we have enough projects that show how you plan and how things actually turn out.”
“The adoption of technology in construction has lagged behind almost everything except hunting and fishing for the past decades,” says Josh Johnson, a consultant at McKinsey who follows the building industry.
A McKinsey report last month predicts a big shakeout across the construction industry over the next decade, with companies adopting technologies and methodologies from the manufacturing world. Things have already begun to change, thanks to technological progress and an increasingly tech-savvy workforce, Johnson says. The pandemic is accelerating the shift too, by making it more difficult to bring workers to a site and forcing companies to reevaluate supply lines and processes. “It’s forcing many of these legacy [construction contractors] and large companies to begin investing,” Johnson says.
Arevalo, who oversees deployments of Canvas’ robot, says the drywalling robot cannot tackle corners or angles like a human; she says many apprentices see working with the robot as an opportunity to learn how to use more advanced robotic machinery.
The company also has the backing of the local union. “It’s critical for skilled workers to have great resources in their tool kit, and we are excited to be on the leading edge of technology in our industries by partnering with Canvas,” Robert Williams III, business manager at District Council 16, International Union of Painters and Allied Trades, said in a statement.
But this apparently hasn’t quelled concerns among construction workers who’ve seen the robot in action. “They love the fact that it’s so consistent, that the wall is gorgeous,” Arevalo says. “But then the next question is, ‘When is it going to take my job?’”