Exterior building cleaning is big business in the U.S. According to IBISWorld, the industry, which provides exterior cleaning services for both commercial and residential buildings, is valued at $12 billion, includes 132,048 businesses, and employs 186,773. And it’s not slowing down anytime soon, given that our country’s 5.9 million commercial buildings, which contain a total of 79 billion square feet, are growing in number and size. At the same time, many traditional methods for cleaning building exteriors—such as window washing by hand—are wildly antiquated. Consequently, there have been some recent innovations in cleaning technology aimed at giving the industry a makeover.
One of the most exciting new techniques to wash windows uses drones. Lucid Drone Technologies has developed industrial spraying drones that can clean exterior building surfaces and windows at a much faster pace than traditional methods. These drones are tethered to an on-ground pump system with a hose, operated by remote control, and equipped with sensors that help them avoid obstacles. The technology is particularly useful in cleaning areas that are hard to reach due to the height or shape of a building.
That said, cleaning drones aren’t ideal for congested cities, where spaces between buildings are tight, traffic is constant, and drones are heavily regulated by the Federal Aviation Administration (FAA). Enter robotic window cleaners—another innovative cleaning technology that has recently come onto the scene. Companies like Skyline Robotics and Verobotics have already started using them in places like New York City and Israel.
I talked to Skyline Robotics CEO Michael Brown to learn more about how his company’s recently patented window-cleaning robot works. He explained that it sits in a conventional basket that is suspended from the roof (the same kind that traditional window washers use). The robot itself uses a remote sensing technology called LIDAR (light detection and ranging) to map the side of the building, which can be very difficult to do since windows have translucent and reflective surfaces that can be hard to identify due to things like sun angle and shade.
But once the robot isolates the frames of the windows, it sprays deionized (purified) water onto the glass and rubs it in with sensor-guided brushes. “It’s almost like you’re painting between the lines,” Brown said. “The robot knows, there’s the window, clean between, make sure you get everything off.” And because it uses deionized water, it doesn’t leave any streaks. It gets the window sills and everything else before the unit is lowered and the process is repeated.
The biggest problem that window-cleaning robots solve is the need to put workers in danger, sometimes hundreds of feet off the ground. Though there are only a few window-washing deaths per year and many in the profession actually relish the thrill of hanging from tall buildings, it’s unnecessarily dangerous. As window washer Tony Natoli told the New York Times, “You only get to fall once.” Robotic window cleaners eliminate this risk, saving lives and lowering companies’ insurance costs.
They also help alleviate the growing labor shortage. Many window cleaners are nearing retirement, and there simply aren’t enough people coming into the profession to replace them, with the average age of an employed window washer sitting at 48 years old. By operating at a higher efficiency and scale than humans do, window-cleaning robots can help fill this void. At a minimum, they are three times faster, Brown said, and there are several reasons for this. For one, a company that hires a human window cleaner for an eight-hour shift only gets about four hours of labor once you account for the time it takes them to get up and down the building, have lunch, take bathroom breaks, etc. In contrast, robots can work the full eight hours uninterrupted.
But what’s perhaps even more revolutionary is that robots have the ability to clean at night. “Because we use LIDAR, we’re able to map the building and we don’t need any lights,” Brown explained. “So we believe that commercial cleaning will be moved to nighttime and residential cleaning of buildings will be done during the day.” This lets companies leverage additional time that previously went untapped, and it eliminates the need for people inside to see workers dangling from the outside of the building as they’re in a meeting.
Still, implementing robotic window cleaners has its challenges, including getting past regulations and working with organized labor. Skyline Robotics is trying to do both. With traditional window cleaning, “one person is on the roof, two people are in the baskets,” Brown said. “We’re eliminating the two people in the baskets, retraining them to become robot technicians. So those two people can clean two other buildings.” For now, however, Ozmo still operates with one person on the roof and one person in the “basket” due to regulations.
Apart from robots and drones, new building cleaning technologies also include things like self-cleaning coatings, which repel dust and dirt to minimize the need to clean in the first place. There are also prototypes of electrostatic and laser cleaning systems but all of these are still in the research and development phases and not yet widely available.
The real question is whether these new technologies will permanently change the way we clean the outsides of buildings. On the one hand, they have the potential to improve worker safety and increase overall efficiency. On the other hand, they require a significant upfront investment in the machinery, training, and maintenance involved. Companies that want to transition to more advanced cleaning tech will pay a premium—at least in the short run. This can be hard to do when the average window washer charges only $17 an hour according to Zip Recruiter.
It’s also important to note that cleaning regulations will need to adapt before companies can take full advantage of things like spraying drones or robotic window cleaners. Just because the technology is there doesn’t mean the laws are there to support it. Brown told me, “I could run this machine without humans right now, not even on the top. But it’s not possible due to regulations.” And as long as laws require this kind of handholding, the marginal return on investing in these new cleaning technologies will be limited.
Some building owners are already seeing a long-term benefit of new window cleaning tech. Skyline has already worked on some high-profile skyscrapers, including 383 Madison Avenue and 7 World Trade Center. New window cleaning techniques appear to be the future, but for them to make a significant impact they will need to overcome some regulatory huddles and become significantly more economic than the current methods. My guess is, that isn’t too far off.