Contractor Mayo Makinde stood inside the two-foot-tall cement framework of what will be an 850-square-foot house and gestured to where some of room would be – the main bedroom, the second bedroom, the foyer.
The low, double walls that surrounded him were made of thin layers of concrete poured one on top of another, but there weren't cement trucks or concrete forms in sight. Each layer came from a 3D-printer.
Tucked off 26th Avenue in the Linden neighborhood, the house is set to be Columbus’ first 3D-printed home.
It took about three and a half hours to build the first two feet. Makinde, owner and operator of Makinde Enterprises, printed another six feet of walls on Sunday. He expects to finish the exterior walls of the house on one more work day within a few weeks.
“It's going to, is a radical change into the way homes have been built,” he said.
A massive 3D printer looms above the fledgling structure. The nozzle that dispenses concrete sits on a tall metal frame, which can travel along a set of tracks. When it’s running, all of its movements – from the mixer and the pump to the nozzle itself – are controlled by a computer.
Makinde said the up-front cost of the printer is high at about $1 million. He got his through a partnership with Spanish company Bemore. Materials to print the Linden house cost around $30,000, plus Makinde has to pay his workers.
But he believes once builders have the printer and perfect the process, 3D printing will become cheaper and faster than traditional building. Makinde speculates that one day, building a 3D house may cost just half as much as other types of construction.
“I think that we can definitely cut the cost of building and in the United States and in Columbus,” Makinde said.
Building solutions
Supporters tout 3D concrete printing as a solution to building fast, affordable housing. In theory, a house, including plumbing, roofing, windows and doors, could go up in about seven days, Makinde said.
But the technology is new and comes with plenty of unforeseen hiccups.
When asked about the future of 3D printing, Nathan Ames, director of Ohio State University’s Center for Design and Manufacturing Excellence, gave an honest answer, “I have no idea.”
“I think that's the that's the answer that everybody should give,” Ames said.
Ohio State’s CDME has one of the nation’s largest 3D printing programs, focused mostly on printing metals and polymers. The program employs around 150 undergraduate students who work on real projects for industry professionals and the federal government. When students graduate, they come ready to work on the products they helped develop, Ames said.
OSU has worked with a large-scale concrete printer like the one being used to build the house in Linden. Ames said he and students were using it to research ways to make large-scale concrete molds.
Right now, however, OSU’s printer is on loan to Somerset Community College in Kentucky. Students there will use it to build low-income houses in Appalachia.
Like Makinde’s aspirations of cutting construction costs, it’s a noble goal. But Ames doubts the technology is ready for the fast, mass-production that makes affordable housing – well, affordable.
“It's not necessarily the cost to build the house. It's the cost with all the time associated with the unknowns,” Ames said.
Unknowns like, how do you inspect a 3D-printed house? Will the temperature and humidity be right to print on the scheduled day?
“Or, if you're in, yeah, if we're in Ohio, it's probably started raining three times, right?” Ames joked.
Working around hiccups
The city of Columbus approved construction of the Linden house back in January but hit a few hiccups of its own.
The parcel proved too narrow for the large printer, so the house had to be set back further than others on the street. Then, Makinde’s first concrete pour stopped sooner than planned because of an issue with the material.
“There's always things you don't know until you till you know,” said Columbus Deputy Director of Building and Zoning Anthony Celebrezze Jr.
Celebrezze Jr. said despite setbacks, the Linden house is expected to meet city building requirements. He also said Columbus is open to more 3D-printed houses.
“Structurally, they’re – they’re a sound house. So, the people shouldn't be scared of them,” Celebrezze Jr. said.
Potential of 3D printing
Ohio State's Ames believes more than saving costs, the real potential behind 3D printing – whether it be concrete, metal, or polymer – is the design freedom it offers.
“So, 3D printing is a little bit like stacking clay,” Ames explained.
You can stack different materials with different conductivities, create shapes with caverns, or vary the strength of materials.
“That's the benefit that that today's industry is trying to capitalize on.
As 3D printers become available to younger and younger students in schools, Ames also sees the technology opening up 3D thought for children as young as kindergarten. He said that before, that kind of thinking was reserved for high school and college students.
“What are they going to create because of all the all the new pathways in their mind that have opened up?” Ames asked. “I can't wait to see where the world goes because of 3D printing.
Building up Linden
The Linden house will be one of the first 3D-printed homes in Ohio. Sustainable Concrete Innovations built one in Wapakoneta earlier this year.
Local contractors Corbin Dotson and Justin Whitehead stopped by to see what it’s all about. They’re excited.
“We wanted to see what the new wave is, you know?” Whitehead said. “It’s going to be a game changer.”
Makinde's house set to become an Airbnb for his nonprofit, Makinde Foundation. Makinde said one of the main goals of the foundation is encouraging young people to explore the construction industry.
When it’s not rented out, Makinde said he’ll open the house to the public. He plans to leave the concrete walls visible, so people can see what makes the house different.
He also wants the house to be a visible symbol of progress in Linden. He said his neighborhood sometimes gets a bad rap, but good things can happen there.
“I just want children to know that if you can imagine it, it can happen. And also, that Linden can have something they can be proud of,” Makinde said.
