The goal of achieving, as ICON cofounder/CEO Jason Ballard puts it, “twice the quality, at half the cost, in half the time” remains elusive. While many companies are reluctant to reveal monetary figures, rough comparisons between printed and framed walls suggest meaningful savings in time, labor, and materials. House Zero and its ADU were printed simultaneously with a single gantry machine in 10 days at approximately half the cost of comparable stick-frame walls, according to one traditional contractor. For a 1,700-square-foot house for Habitat for Humanity, in Tempe, Arizona, built in collaboration with German-based Peri Group construction company, the walls took two to three workers about three weeks. “By contrast,” says project lead Samuel Hager, “that usually takes our crews of 20 to 30 volunteers one to two months.”

Ideally, the walls, once printed, are completely done. Lake | Flato exposed the concrete inside and out at House Zero, celebrating the process while achieving a surprisingly soft look from a hard material. But not every designer and builder finesses the technique so deftly, and not every client appreciates a corduroy texture. Though robotic techniques exist for smoothing printed surfaces, interior walls often get old-school treatments, including drywall and paint. But even then, most 3-D-printed shells, eliminating needs for vapor barriers, cladding, and more, have fewer layers than conventionally built ones, while achieving, it is believed, thermally superior results. (Along with their precise and complete seal, layered printed walls can be designed to eliminate energy-inefficient thermal bridging, as found in stud construction.)

Photo courtesy of Casey Dunn

3-D-Printed structures by ICON include House Zero..

Photo courtesy of Joshua Perez

Housing for families experiencing extreme poverty in Mexico.

Photo courtesy of Regan Morton

A demonstration project in Austin designed by Lake | Flato; housing for the chronically homeless, also in Austin.

Another important advantage to 3-D printing, says AICT cofounder Zoey Zhao, is “the digital files created by architects with engineers are exactly what gets printed—with certainty up front about the time required.” (Assuming no glitches.) Also, with chases printed into walls, says Hager, “you’re not waiting for framing to finish before beginning electrical or plumbing—it’s so different from the linear one-trade-at-a-time schedule of conventional home construction, where a single hiccup can have ripple effects, causing delays and cost overruns.”

When companies cite the number of printing “days,” however, the total hours aren’t necessarily sequential, but spaced out over longer periods. And the assumption that the machines will run 24/7 can also be misleading, as many neighborhoods don’t allow around-the-clock construction; some printing materials require curing time between layered sections; and the equipment still needs continual oversight from human beings. Besides, claims of quick-printed houses don’t often publicize the time taken to finish the traditional parts. Both House Zero—a high-end design with top-quality finishes—and the affordable, traditional-style Habitat home in Arizona took nearly a year, including pandemic and supply-chain delays, to complete.

A myth, propagated across the internet, is that ICON has printed small houses for only $4,000 each. “I wish it were true,” says Bal­lard, “but not yet, anyway.” Although his company generally declines to disclose costs, it has confirmed that, more realistically, it built a 350-square-foot house in 2018 for $10,000—but that amount only covered the walls.

Still, without compromising quality, the method offers some cost and time savings that can help address global housing shortages. “Even if we worked nonstop with traditional methods, there aren’t enough hours for human laborers to meet the growing need,” says Ballard. “Every year, we’re millions of homes deeper in that hole—particularly for affordable options. This calls for a paradigm shift.”

ICON has already built clusters of small but thoughtfully designed houses for impoverished families in Mexico, in collaboration with the nonprofit New Chapter, and for chronically homeless people at Community First! Village, in Austin. Habitat for Human­ity has printed a house in Virginia, in addition to the one in Arizona. And AICT’s design for housing in Kenya (so far, a single prototype, constructed in China) was commissioned by the United Nations Refugee Agency, UNHCR. 3-D printing could also potentially address emergency disaster relief.

With housing shortages spanning income levels, Mighty Buildings is currently focused on the “forgotten middle—firefighters, teachers, and others,” says Ruben, adding that his company aspires to ultimately address a broad demographic spectrum. Scaling and speeding up the process, Mighty is working with the developer Palari Group and L.A.-based Ehrlich Yanai Rhee Chaney Architects to print a cluster of 15 houses in Rancho Mirage, California. ICON is partnering with Lennar homebuilders to print a community of 100 houses near Austin, co-designed with BIG-Bjarke Ingels Group.

Photo courtesy of EYRC Architects

Some Companies print and assemble modules in a factory, as Mighty Buildings plans to do for a group of houses in Rancho Mirage, California, designed by Ehrlich Yanai Rhee Chaney.

Illustration courtesy of Mighty Buildings

While the U.S. has not yet permitted 3-D-printed construction above one story, changes allowing taller buildings are in the works. In Asia and Europe, where the technology took off years ahead of the U.S., higher structures already exist. In China, in 2015, Winsun completed a five-floor apartment building incorporating printed walls; and a three-story residential low-rise went up in Germany last year.

Regarding concerns that 3-D printing will eliminate work opportunities, proponents maintain that it will introduce different (although probably more skilled) jobs; that the current labor shortage is real; that automation in other forms is already happening, by necessity, across construction industries; and that printing will provide one valuable approach among others that will remain.

Meanwhile, the industry continues to gain momentum. Last year, Dubai—known for showcasing cutting-edge approaches—issued a decree, requiring 25 percent of its new buildings to be 3-D-printed by 2030. And ICON is collaborating with NASA for printed dwellings in outer space. But the idea that we can press a button, and a finished house will pop out—we’re not quite there yet.

Supplemental Materials:

“A Systematic Review and Analysis of the Viability of 3D-Printed Construction in Remote Environments”, Steven J. Schuldt, Jeneé A. Jagoda, Andrew J. Hoisington, Justin D. Delorit, Automation in Construction, Volume 125, May 2021
[Section 4. Results: Evaluation of Viability Factors]