Mighty Buildings had what it considered a mighty idea. Amid the construction industry’s inefficiencies and persistent labor shortages, the three-year-old, Oakland, Calif.-based company found a solution to more quickly meet the demand for affordable homes in the Bay Area.
By combining 3D printing, prefab construction, and robotics, the company learned it can produce homes in 95% fewer labor hours—twice as fast as the conventional building industry does.
Part of the speed comes from automating 80% of the construction process. The company 3D prints the home’s structure using a proprietary material—a lightweight synthetic stone that’s similar to Corian—which it had certified by Underwriters Laboratories. The material has a higher thermal resistance than concrete, which also makes it more energy efficient. Robotics add foam insulation and interior millwork, and applies exterior finishes such as stucco or paint. It can also minim the look of siding or brick. Workers add the finishing touches on anything that’s too complex for robotics to do efficiently, such as installing cabinets, fixtures, faucets, and hardware.
“It’s similar to how cars are produced,” says Alexey Dubov, COO and co-founder.
To make its product sustainable, Mighty Buildings has eliminated most waste through recycling, such as converting dust from the milling process into new materials, says Sam Ruben, another co-founder and the company’s chief sustainability officer.
By starting with small residential buildings—just a 350-square-foot studio—Mighty Buildings found it could finish a free-standing dwelling in less than a day and truck it to a homeowner’s site. Because of the speed of delivery and materials, costs are also reduced by as much as 50% versus traditional on-site construction, and are 20% to 30% less than traditional prefabrication methods.
The company envisioned its first studios as turnkey accessory dwelling units, which California permits on single-family residential properties as a way to increase density and ease the state’s massive 3 million-unit housing shortage. As of September, Might Buildings has finished two 3D-printed units, each with a steel frame and curved printed walls. “We wanted to get a product to market fast, and the steel wall made it easier for building officials to say yes,” says Ruben.
The two completed units were installed in San Ramon and San Diego, with additional units awaiting delivery. “The San Diego customer had planned to rent it out but loved it so much he’s moving into it and renting out his house. The San Ramon client plans to use it as a guest house,” Ruben says.
The housing product became the first certified under California’s Factory Built Housing program for units using 3D printing. Mighty Buildings plans to eventually produce them for customers outside California, Ruben says. “Ideally, we’d have factories in each area where we’re printing,” he says.
The starting cost for a 350-square-foot studio is $115,000, plus utilities, site, and delivery/installation costs. Prices vary according to the area and necessary foundation, permitting, and labor costs. A larger, 700-square-foot model is projected to cost $159,000 to $169,000.
The company is also working on a much larger, 1,500-square-foot panelized design with one to three bedrooms and one or two bathrooms that would range in cost from $185,000 to $285,000. Those would be erected on-site.
The company’s ultimate goal is to work with other partners to fashion a variety of homes, some multifamily floor plans, and commercial buildings. “Longer term, we hope to market an agnostic tool to build across different segments of the housing market,” Ruben says.