3D Printing Houses: The Future of Homebuilding

While building a home with 3D printing sounds like a futuristic idea, that future is actually already here. Multiple companies and researchers are testing the technology and building 3D-printed homes, typically with concrete walls created with a 3D printer. 

The technology for 3D printing, also known as “additive manufacturing,” has been around since the 1980s. As the technology improved through the 1990s, 2000s and 2010s, 3D printing began to be used for larger and more sophisticated items. While the use of 3D printing is not widespread in the housing industry, multiple homes have been built using this technology in the United States and around the globe. 

“Building a home with 3D printing requires less lumber, less labor and less time,” says Kirk Andersen, director of operations for SQ4D Inc., a construction technology company on Long Island in New York. “The process saves about 20 percent of the cost of building a home now, but five to 10 years from now we think it can save as much as 40 percent to 50 percent of construction costs.”

Saving Time and Money With 3D Printing

Many people in the housing industry hope that 3D printing will offer a solution to the affordable housing crisis in the United States and the severe shortage of homes. For example, Virginia Housing, a statewide organization that supports affordable housing initiatives, awarded a $500,000 innovation demonstration grant to the Virginia Center for Housing Research at Virginia Tech (VCHR) for a 3D modular construction printer to print the concrete walls for the first 3D-printed home for sale in the state. 

“Our mission is to cut construction costs across the board and develop affordable housing in rural counties and urban areas,” says Zachary Mannheimer, founder and CEO of Alquist, a 3D printing construction firm based in Iowa and a partner in the Virginia project.

The VCHR demonstration home is designed to be affordable, durable and aesthetically pleasing, says Andrew McCoy, director of VCHR. The 1,550-square-foot home in Richmond is expected to be complete in early October 2021 and will be listed for sale for approximately $210,000. The three-bedroom, two-bathroom house includes a laundry room and a front porch with a swing. 

VCHR estimates that the cost of building with a 3D printer is at least $10 per square foot lower than building with lumber. As lumber costs have risen sharply over the past year, along with other building materials, the gap in expenses may widen. 

“We can print on-site, which saves transportation costs and time,” Mannheimer says.

The VCHR house will include concrete exterior walls designed in two sections with a space in the middle for foam insulation. The house is anticipated to be about 50 percent more energy efficient than code requirements for newly built homes. The interior walls will be made of drywall, although it’s possible to construct the entire home of 3D-printed concrete.

“A big component of 3D printing is the flexibility,” McCoy says. “You can print the footings, subfloor, joists, roof trusses and walls within a few weeks.”

The reduction in time and labor costs make 3D printing ideal to address the inventory crisis and affordability issues, says Chris Thompson, director of strategic housing at Virginia Housing.

Lower energy costs are another benefit of 3D-printed homes. Concrete homes retain temperatures better than other materials, which saves on heating and cooling costs. Reducing energy costs adds to the affordability of operating the house for future owners.

In addition, says Andersen, concrete structures are extremely durable and resilient. “Because our machine can be used on-site rather than in a factory, this can be a solution to disaster relief after a storm or a fire destroys homes,” Andersen says. “We can show up, build homes quickly and then move on.” 

Printed concrete exteriors offer maintenance-free benefits that are similar to brick, says McCoy. “In the Richmond house, where humidity is high, we coated the outside to trap moisture and added overhangs to prevent water from hitting the concrete,” he notes. 

How 3D Printing Works

Large-scale 3D printers can be used on-site to print walls or can be used in a factory to create prefabricated walls that are then delivered to a construction site. Since SQ4D’s machine is used on-site, the only transportation needed is to bring the 3D printer to the site rather than to transport heavy concrete walls, says Andersen. 

“The machine we have now only prints one-story walls, but in the future, we’ll have a machine that can print a three-story house,” Mannheimer says. 

The walls of the Richmond house are hollow to allow for insulation, but in locations with high winds and hurricanes, columns and beams can be added for additional strength. “We can print a column, if needed, to fit in between the inner and outer walls for stability during earthquakes,” McCoy says. 

And as Andersen points out, concrete is resilient, abundant and affordable. 

“We invented and developed the technology to extrude concrete for the interior and exterior walls and the footing and foundation of a home on-site,” he says. “Right now, we’re using concrete, but it’s possible to use other materials such as plastics or clay.”

SQ4D built a 3D demonstration house in Riverhead, New York, with approximately 40 percent coming from the 3D printer, with the rest traditionally built and installed such as trim, finishes, plumbing and electrical systems. 

Layer by layer, the 3D printer creates eight-inch-thick walls with five inches in between for insulation. Andersen’s machine can create walls as tall as 10 to 12 feet. The demonstration house in Riverhead required 48 hours of printing time spread over eight days. 

“The style of the house we built was pretty simple, but we can definitely do more unique homes eventually,” Andersen says. “The printer can do any shape, including circles, triangles, squares and rectangles.”

Future of 3D Printing for Homes

The ability to build 3D homes depends in part on jurisdictions adapting their code to allow for this type of construction.

“We proposed the Virginia project at the beginning of the pandemic and got feedback from the zoning and planning offices on the design,” McCoy says. “We didn’t want to push the envelope too much, so we opted to use drywall for the interior walls. But now I think we could do the entire house from durable 3D-printed concrete.” 

Rather than eliminating the need for labor on building sites, 3D printing shifts the skills needed, says McCoy. He’s convinced that within five years some elements of homes will be printed at home improvement stores, which should encourage more people to get trained to use the equipment. 

“The building industry is ripe for disruption,” Mannheimer says. “We need to work with builders and with workforce development agencies to provide the training needed to build with 3D printers.”

Andersen is optimistic about the future of 3D printing.

“I think in the next 10 years we’ll start to see 3D-printed homes everywhere,” he says. “In 20 to 25 years, we’ll see robots doing a lot more than they are now. In the future, we’ll see a mix of prefab and additive manufacturing for homes, which is really the best of both worlds.”