A plan by New York architect Adam Kushner to build his three-bedroom house, along with a swimming pool, hot tub, pool house, and car port, in Gardiner, N.Y., is facing no shortage of holdups. Though designing one's own home can be daunting in and of itself, in Kushner's case, the devil is in a different set of details: getting a large-scale, concrete 3D printer across the Atlantic and onto his five-acre lot.The proposal by Kushner, founder and principal of design firm Kushner Studios, is among the latest in a recent spate of plans to 3D-print full-scale buildings. Several structures—including a 12,000-square-foot residence and a five-story apartment block—have been printed in discrete units and assembled in China. Others are in the works in Amsterdam and throughout the United States (here’s one example from Minnesota).
While those projects focus on modular construction, Kushner wants to print his estate from the ground up. He plans to iterate slowly: First the hot tub, the 2,200-square-foot pool, and the 550-square-foot pool house because they don’t require rebar, a major hurdle in seamless 3D printing. Next, the carport and, finally, the roughly 2,200-square-foot house.
But Kushner's biggest challenge yet has been getting his hands on one of the few printers capable of doing the work. “I know the unknowns that I need to know, and I already know how I want to go about solving them, but until I have the machine in front of me, I can’t,” he says.Last year, Kushner put out a call for a collaborator who specializes in 3D printing. Only one responded: Enrico Dini, whose startup D-Shape, in Italy, manufactures large-
For now, however, the printer is still in limbo. The Defense Ministry’s standard tests to ensure it meets the specifications of military use were planned for December 2014 but were pushed to February, Kushner says. That delayed his own project, which was expected to break ground this spring. Dini says he’s spent months delivering records and installation manuals to government offices in Italy and “codifying the printer with the NATO codification system,” referring to the North Atlantic Treaty Organization, of which Italy is a member. Kushner puts it more bluntly, saying they’ve been “proving to the generals that this is a nonthreatening device and not a weapon of mass destruction.”Dealings with the Defense Ministry are in the final stretch. The printer passed the required tests this spring (which neither Kushner nor Dini could detail) allowing it to leave the country, and it’s now awaiting transport to the U.S. Kushner anticipates that the printer will arrive for a dry in run a Queens, N.Y., warehouse by August. If all goes well, it will be moved to the Gardiner site, which has already been excavated, by September.
While most printers today feature a single extruder that layers slurry, the printer planned for Kushner’s job is fitted with dozens of print heads that run back and forth to build layers of sand and magnesium, while periodically dropping salt water until a block of material is created. Crushed conglomerate from the Shawangunk Formation excavated at the Gardiner site will be used as aggregate. Once the form inside the block congeals, the looser sand and magnesium are eliminated, which is typically done manually with a blower, Kushner says. Depending on the size of the block, it could take a week or two to blow out and grind down the rough spots. He estimates that the concrete will have an ultimate strength of 3,500psi in application.To get a sense of the printer’s speed, Dini says, a similar-sized but older model of the company’s design produced a 28-foot-tall sculpture over the course of six weeks. The newer model is faster yet, though he couldn’t say by how much. Kushner expects the pool house to print in a day or two, moving the printer progressively around the plan.
Only a handful of large-scale 3D ceramic printers—whose footprints generally exceed 2 meters square—are in use today, Kushner says. With the number of large-scale applications for 3D printing competing for a comparatively small supply of capable equipment, he has had to wait his turn. So far, it’s proving worth it. He anticipates that his estate will cost him from one-half to two-thirds of the $150,000 construction costs for a similar stick-built estate. And the work should go more quickly, he says, despite delays to work out potential technology bugs and, of course, the unanticipated wrinkle of the printer’s stalled delivery.
“We already know the machine works,” he says. “It’s built buildings. It’s built small structures. It’s passed [Italy's] army test. We’ve printed 28-foot-high sculptures. We’re going to put it through its paces, but this is technology that’s been around for five years. We want to achieve that breakthrough moment where we figure out how to make 3D printing a regular part of our construction vocabulary.”