Layer by layer, a new home in Nome is taking shape. Once complete, it’ll become the first occupied 3D printed house in Alaska.
The construction site was recently visited by representatives of the Rasmuson Foundation, one of the funders behind the Nome test project. Workers had hustled through the night to complete a 20-foot wide segment of wall, just in time for the visitors.
While printing, the giant robot arm flexes and reaches side to side as it slowly pumps out a stream of a special concrete mix. The machine prints long and narrow segments of wall, while leaving hollow cavities for spray-foam insulation to later fill.
Rasmuson’s Vice Chair, Natasha von Imhof, reflected on the potential of the project while touring the site.
“Ideally we can build 70 to 100 homes here in Nome to take advantage of the growth of the port,” she said.
Von Imhof was referencing Nome’s massive port expansion project, which was awarded a contract worth $399.4 million just days before her visit.
“Just with the port, the tourism, the military, the transportation, with Northwest Passage, Nome is going to be the hotbed,” she said.
When complete, the house will be about 1,500 square feet – slightly larger than average for the Nome census area – and have a kitchen, laundry and utility room. It also boasts a 3D-printed arctic box for easy access to water hookups to the house, which the builders claim is the first of its kind.
Rasmuson, the Denali Commission and other federal and state partners put together more than $2 million for the three-bedroom house. Over time, the team behind the project plans to get that cost closer to Nome’s market rate of about half a million.
The builders admit this test project was bound to be expensive, no thanks to the airfare involved with flying out its Pennsylvania-based crew. The team also dug out no less than six feet of permafrost to install a fresh base of compacted stone. On top of that is a concrete slab foundation that doubles as the floor, with radiant heat tubing throughout.
“Dare I say this is probably the most sturdy foundation in all of Nome,” a designer on the project, Jeff Berlin, said.
Layers of adaptability
The concrete isn’t too different from what you can buy at the store, but it can’t be as chunky – the slurry has to smoothly pass through a 2-inch wide hose as it prints. It includes some special additives like fiberglass for strength.
The big picture goal is for the system to be adaptable to whatever environment it's printing in, including using locally sourced materials. Concrete for this project came from Anchorage, but rock from the Sound Quarry east of Nome has already been shipped out for testing for future prints.
The project’s second layer of adaptability lies under the machine itself. The entire platform is mounted on two tank treads, allowing it to crawl over bumpy terrain and reposition between prints.
With the push of a button, four giant hydraulic arms extend out to lift the entire machine off the ground. The 12,000-pound machine self-levels, making a sturdy base for the robot arm to operate from.
The nonprofit, Xtreme Habitats Institute, is the research arm of the project. The organization’s Executive Director, Keith Comstock, says getting the weight of the machine right was a balancing act.
“It's really heavy because we need to be precise. And when you have the leverage of that arm being fully extended, you know, it can get really wobbly and unstable, and so we need millimeter precision,” Comstock said.
Despite its weight, the whole system is designed to fit in a shipping container. It’s the final layer of adaptability the for-profit component of the project, X-Hab 3D, is banking on to grow the company. Eventually, X-Hab 3D hopes to print buildings on Mars.
What's next
The project has been in the works for years. Last summer, the team ran a test project in Fairbanks, with the hopes of pushing on to Nome later in the year. They bumped back the Nome house to make tweaks to the special concrete formula used in the machine.
The team plans to finish printing and put a metal roof on the structure before winter, then begin interior work. When complete next year, the City of Nome will take over the property. It plans to test it out as housing for short-term visitors working with the city.
The project could become the first inhabited 3D-printed house in Alaska. If Rasmuson has their way, with a potential boom in Nome on the horizon, it may not be the last.
