An 11-foot-long robotic arm bobbed and weaved a few inches at a time, tracing the shape of a bench.
Usually, it would be spitting out layers of quick-setting concrete. Instead, it was shadowboxing in the middle of the Virginia Beach Convention Center as part of the Governor’s Housing Conference last week.
The arm moved quickly but delicately for something attached to a 4-ton piece of construction equipment.
With a few short keystrokes, the big blue 3D printer could be set to print just about anything — the concrete walls of a new home, for instance.
Virginia Tech researchers and Virginia Housing, the state’s housing agency, are hoping this evolving technology can spur quicker and more affordable housing development in a state that desperately needs it.
“We're in a severe housing deficit. We need more inventory, and we are just looking for new ways to get more houses built and help alleviate some of that pressure,” said Chris Thompson, Virginia Housing’s director of strategic housing.
Rents across Virginia increased an average of 24% between 2013 and 2023. Many advocates say building more housing is the best way to meaningfully increase affordability.
The big draw for 3D printing compared to traditional construction is that it can cut down on time, said Virginia Tech housing research director Andrew McCoy. Saving time in construction typically means saving money.
“We're taking the exterior walls, for example, which include many different materials, processes and labor, and we can hopefully consolidate that into a system that saves us money on all the different time constraints that we have across the trades and getting people in and working,” McCoy said.
He noted that a labor shortage in key construction trades often means big delays at job sites as homes sit waiting for a mason or carpenter.
Virginia Housing has issued a $1.1 million grant for Virginia Tech to bring the big blue printer to construction sites and show off what it can do by building 10 affordable homes in conjunction with commercial builders. They’re still figuring out where those will be built.
The grant is meant to lower the financial risk of trying out 3D printing for developers, providing both the technology and training to give them an up-close look at the process and convince them it’s worth the effort.
“We're hoping that we can plant the seed and show that there's a proof of concept and that this is a viable way of building,” Thompson said.
Home printing is still in its infancy in the United States. Some startups are bringing 3D printed homes to market, but they’re few and far between. Virginia Tech has been at the front of the pack, printing two homes in the state in 2021 — one in Richmond and another in Williamsburg.
But those projects and others since also showcased the limitations of some of the technology and methods. The printer they used before had to be moved with three different semi-trucks and needed a crane at the construction site to assemble it.
The new printer the university is buying from India-based Tvasta Construction is a big step forward, McCoy said. It moves under its own power on treads, like a Bobcat excavator, and can be loaded on and off a flatbed trailer towed by a pickup truck.
The mobility adds a ton of flexibility, McCoy said, both in getting it to the job site and moving it around once there. That will enable builders to use it exactly where and when they need it.
The scaled-down machine also prints at the same rate as the huge, cumbersome printer researchers used to create those earlier homes.
The Virginia Housing grant will also support researchers’ efforts to better understand the printing materials and develop alternatives, including more eco-friendly, less carbon-intensive options than the current concrete.
“The concrete itself is expensive, and we're increasingly seeing it as something that we need to refine,” McCoy said. “We're looking at plastics, we're looking at foams, things like that, all kinds of different things that we can put on this robotic arm and print.”
