Why 3D printing could be a boon to two of Maine’s big goals: climate and affordable housing

It’s loud inside the University of Maine’s Advanced Structures and Composites Center, where students and engineers soar above noisy lab equipment and large ceiling fans whirl overhead. And that’s without the world’s largest 3D printer working.

Habib Dagher, the centre’s executive director, says the printer is down at the moment. But once it’s up and running again, it’ll print test modules for the center’s latest attempt – a 3D-printed house.

This story is part of our “Climate Driven: A Deep Dive into Maine’s Response, One County at a Time” series.

In Maine, there is a shortage of nearly 20,000 affordable housing units for low-income households, according to the National Low Income Housing Coalition. And nationally, that number is closer to 7 million.

Dagher says this project could eventually alleviate those challenges. At least, that’s the goal.

He points to a module sitting on a platform near the printer and indicates that the beginning of what he says will eventually be a curved roof.

It is hard to imagine that this structure, which almost looks like very thick and very strong cardboard, could one day be the floor, the walls and the roof of someone’s house.

“Once this module is completed, we can go in and complete it,” says Dagher. “If it’s the kitchen, you can actually put the kitchen cabinets in there, you can start running the wiring in there, and so on. And then once all the modules have what they have in them , so when they get to the site, it’s just a matter of putting the modules together and hooking things up.”

It sounds simple, but Dagher says if his team can pull it off, it will be after years of trial and error. So far, early tests are promising, and the university believes it is well on its way to building the world’s first bio-based 3D-printed house.

Efforts have been made around the world and in the United States to 3D print new homes. But Dagher says the vast majority of these homes are printed with concrete, and a 3D printer is typically only used to lay the house’s foundation and maybe the walls.

“We print the whole house,” he says. “We don’t print it with concrete; we print it with wood, which is a renewable resource that has a much better carbon footprint than concrete. And if it’s a renewable resource, we can help capture the carbon, it also becomes a carbon storage capacity.”

The construction of traditional buildings accounts for around 40% of global carbon emissions.

But the University of Maine has spent years experimenting with a more durable material that can be fed through the printer. The material used for this 3D-printed house is made from wood flour — essentially sawmill waste — and mixed with a corn-based binder, Dagher says.

The material could be a win-win, both achieving net zero or even negative carbon emissions for building construction and providing another business opportunity for Maine’s forest products industry.

“We’re printing on a massive scale,” says Susan MacKay, Senior Manager of Research and Development at the Composites Center. “So there’s an opportunity to divert forest residues and forest products to a high-volume application. It’s very important because Maine has historically served the paper industry. And you can’t replace the industry. paper, but you can supplement it with other value-added, large-scale industry types.”

The material is also recyclable. Large 3D printed objects can be crushed and the material can be reused to print something else. Dagher says his team is testing how often it can be reused, potentially up to five times.

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Center for Advanced Structures and Composites

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University of Maine

The university’s 3D printer can print 150,000 books per hour. Habib Dagher, executive director of the Advanced Structures and Composites Center, said his team is working to expand the printer’s capacity to 500,000 books per hour by fall.

Beyond the environmental benefits, the university’s 3D-printed homes could also help Maine meet its affordable housing goals.

MaineHousing wants to build 1,000 new affordable homes every year. At this rate, it would take 20 years to close the state’s current affordable housing deficit of 20,000 units.

Mark Wiesendanger, director of development for MaineHousing, says building houses has become increasingly difficult to achieve, even though the state has more money for it than before.

“That’s great, but the problem is that construction costs have gone up so much that those dollars haven’t gone as far as we originally thought,” he says. “And there are so many projects under construction right now that nothing is happening quickly.”

But with this kind of 3D printing technology, Dagher says the whole house is printed and filled inside a factory, meaning developers don’t have to worry about construction delays in the winter. .

“Imagine one day when you need a 600-foot low-income house and here’s the design, and you can send the designs here to the factory,” he says. “The factory, within a week, can print what you need here, or less, and deliver it to the site.”

MaineHousing worked with the university and a private architectural firm to design a prototype single-family home that meets the agency’s building, accessibility and energy standards. So far, Wiesendanger says initial tests show the model to be insect-resistant and tolerant of variations in heat.

Dagher is cautiously optimistic. The university plans to print four more modules and assemble them.

“We will fix [the home] right behind our lab and make sure we get it before the end of the year, so it goes through a really nice Maine winter, with sensors on it,” Dagher says.[We’re going to] make sure it works and does what it’s supposed to. We will learn a lot from this experience.”

Even if the weather tests are successful, it will take time before small neighborhoods of affordable 3D-printed homes appear in Maine, says Wiesendanger.

“I see the biggest hurdle right now is that this industry…it doesn’t exist,” he says. “We’re really building the ship as we fly it.”

3D printers themselves are expensive, and many other organizations will need to enter the market to make homes affordable for those who need them, says Wiesendanger. The University of Maine relies on federal grants and partnerships with the U.S. Department of Energy’s Oak Ridge National Laboratory to get these projects off the ground.

“But it’s really something that could change the way we build housing around the world,” he adds. “And I think this is a great opportunity for Maine to start a new industry and be a leader in it.”

Dagher points out that there are constant setbacks in this search. But he remains hopeful that his team can prove that 3D printing works and that one day it could be part of the solution to both the climate crisis and the affordable housing crisis.