There’s been a buzz lately about mycelium, a material made from fungi that are being used as a greener substitute for leather and plastic in products such as clothing and packaging.
But more than a decade ago, designers were talking about mycelium’s potential for another use — as a building material. This could lead to the construction of healthier buildings made of components that are grown instead of manufactured and can be triggered to biodegrade at the end of their life, instead of piling up as demolition waste in landfills.
Mycelium is the root network of fungi, which in nature help decompose materials like wood and leaves, recycling their nutrients and storing their carbon in the soil.
But it can also be grown by humans from waste materials such as sawdust or agricultural residues such as plant stalks and husks, recycling them and generating a new material or product within weeks in a low-cost, low-energy process compared to traditional manufacturing.
It can even be grown to a particular shape, similar to the way concrete is cast.
Joe Dahmen, an associate professor at the University of British Columbia School of Architecture, said people first became interested in mycelium for construction about 15 years ago as a substitute for foam insulation, which isn’t biodegradable and can pose a potential health hazard.
“There’s a real tie-in here with healthy buildings,” he said, noting that he became interested in mycelium as a replacement for formaldehyde-based glues.
Mycelium can be used for a variety of building elements. For example, the Italian firm Mogu already sells flooring tiles and soundproofing wall panels made from mycelium. The British biotech firm BIOHM is working to develop mycelium-based insulation panels.
A number of projects around the world have also used mycelium bricks as a construction material. They include Hy-Fi, a pair of two-storey cylindrical towers that won MoMA’s Young Architects Program competition in 2014, and the Mycelium Martian Dome installation by Toronto artist Tosca Teran at the Ontario Science Centre in 2019.
In most such projects, the mycelium is no longer growing. But Dahmen has experimented with projects in which the fungi remained alive, fusing bricks together and even producing mushrooms.
They include a brick wall and a set of benches created with his wife, Amber Frid-Jimenez, Canada Research Chair in Art and Design Technology at Emily Carr University, and their design studio, AFJD.
“As architects and designers, we were really interested in the idea of a material that might aggregate and continue to grow once it was in the shape or form of whatever it was we were designing to,” Dahmen said.
He said fungi can also go dormant to get through dry spells. Indoors, mycelium tends to dry out, becoming stronger and less spongy over time.
“But that doesn’t mean they can’t reawaken later.… What seems exciting to me is the idea that we could include these materials in a building and they would be inert and non-toxic during the life of the building. Then, in the right conditions, they might reawaken and start digesting the materials.”
Dahmen acknowledges it’s important to be able to make sure it only happens at the right time, and the challenge of designing materials for long-term investments such as buildings is bigger than designing materials for products such as clothing.
“I’m also equally confident that we will ultimately get to building components made of these materials,” he said. “It just might take a bit longer.”