Imagine: At the push of a button a team of machines jumps into action, taking a digital blueprint and transforming an empty lot into one with a physical home in just days. They finish on time, on budget, and with zero waste.
This Jetsons-like vision of an automated future has come largely true for car manufacturing. Now engineers hope buildings will be next. From Apis Cor’s 3-D printed house to the MIT Media Lab’s new multipurpose robotic arm, startups and research teams alike aim to spark a digital revolution in an analog industry that has thus far proved resistant to disruption.
In a California parking lot last July, a 50-foot wide, 12-foot tall semi-domed structure arose over just two days, as a a robotic arm mounted on self-driving, tank-like treads spent 13.5 hours depositing layer after layer of plastic foam until it ballooned into a giant yellow beehive. MIT hopes its Digital Construction Platform (DCP), which it presented in the journal Science Robotics in April, will lay the foundation for future buildings.
“We’ve seen huge, huge advances through digital processes for the design side,” says lead author Steven Keating. “But we haven’t yet really seen that translate to the construction site.” Despite the alleged dawning of the Fourth Industrial Revolution, builders still build much like they did before the first one: stacking rectangles, sometimes by hand.
Construction is a massive industry, consuming more raw resources than any other and accounting for 11 percent of all global economic activity. It's inefficient, too: construction produces half of all US solid waste, which makes it a prime target for the precision that robotics offers.
Yet construction sites, unlike indoor assembly lines, lie at the mercy of Mother Nature. And we rely on buildings for our safety far more than we do most other other consumer products.
As such, the construction industry has proven understandably reluctant to innovate, explains Dr. Keating in a phone interview. “They have to be worried about structures standing for 50 to 100 years. Lives are at stake.”
Still, some groups think they’ve made a breakthrough. In February, recent startup Apis Cor’s robotic arm built up layers of quick-drying concrete into the walls of what it calls the first on-site 3-D printed home. Completing the $10,000 model house took one month, including wiring and finishing, and printing the walls took one day, according to spokesperson Konstantin Nefedev.
It’s easy to see the technology’s allure. Printing walls allows builders to accurately predict the time and materials needed, which could bring down costs. Indeed, the University of Southern California is developing the similar Contour Crafting system with the explicit goal of making housing affordable for millions of people in developing countries.
But technology is just one part of the equation. “There are several obstacles – the first being construction codes and regulations,” writes Mr. Nefedev in an email. Russian testing facilities have certified Apis Cor’s concrete as being able to withstand multiple freeze/thaw cycles, but MIT’s Dr. Keating wonders how eagerly the safety-conscious industry will adopt materials that haven't proven themselves with decades of use.
Keating prefers technologies that buttress, rather than replace, the current methods. “Baby steps is how we can actually start to change the industry. If you’re doing it all from the ground up in one giant leap, it’s very difficult to integrate with existing construction worksites’ techniques.”
Instead of going straight for erecting a whole building with novel materials, MIT chose to construct a mold suitable for pouring regular concrete as their proof of concept, a method that is backward-compatible with half a century of construction history.
“If you can come in and replace one key step, which is making that formwork, which defines the entire building’s geometry, you’re already using a system that’s widely used in construction. That’s how you can maybe get some actual real structures built and scale very quickly,” explains Keating.
The robotic arm’s flexibility unshackles cost from form, opening the door to the strength of curvy buildings. “If you look in nature, have you ever seen an animal or insect that has a square-shaped shell?” he asks.
Keating’s also quick to point out that the demo showcases just one feature of the DCP: “I want to emphasize that we don’t call this a 3-D printer. This is a platform.” Like a human hand, its functions are tool-expandable, and currently include site excavation, cutting, surface finishing, and welding chain links into stiff rods.
Alexander Schreyer, a professor of building technology at the University of Massachusetts, Amherst, agrees that 3-D printing could bring welcome efficiency gains, but suspects it will never be a one-size-fits-all solution.
“In construction you’ve always had a mixture of techniques,” he says in a phone interview. “Rather than saying ‘I’m going to 3-D print an entire house,’ I think a combination is ultimately a really good approach.”
Mr. Schreyer says developments are already underway in the form of prefabricated parts that builders assemble onsite: “It’s like putting an Ikea piece of furniture together: it just fits.”
Such techniques are readily available, but their lack of widespread popularity suggests that innovation in construction may face barriers besides technology and regulation.
“We all live in houses that have roughly the same functionality and roughly the same aesthetic. Why on Earth should every house have to be re-thought from the ground up?” asks Schreyer.
“The car industry produces some things in mass and customizes just enough so that people are happy. It’s mind-boggling that that doesn’t happen with houses,” he continues. “I’m assuming it can only be perception.” People may assume prefabricated buildings are less durable, he speculates.
Ultimately, economics may force innovation. Despite the vast sums of money involved, the industry faces margins in the low single-digits. Any method that offers a path to profit will handsomely reward companies who adopt it, but Schreyer suggests none has hit that tipping point yet.
Whether the houses of the future are cast, printed, or prefabricated, experts agree that change is coming, albeit gradually. “I think the world will become more automated, and that includes construction, but I think it’s going to be a lot slower than people expect,” says Keating.
In that sense the construction may resemble concrete itself, with its imperceptible but unstoppable flow. “We all move in a single general direction,” says Nefedev, about MIT’s DCP. “All technologies are progressing in incremental steps – whether it be a step or a leap forward, only time and practice will tell.”