Published on March 1, 2020.

Beyond Concrete

From mushrooms to metals, the world of 3D-printed construction materials knows no boundaries

Many of the high-profile 3D-printed construction projects to date have used cementitious materials, concrete-like mixtures that yield gray, rough-hewn walls that can more closely resemble ancient ruins than cutting-edge architecture. But the versatility of 3D printing technology means virtually any material can be loaded into and extruded from the machines. Here are a few non-concrete materials that have been researched for use in 3D-printed buildings or building components.


Plastic isn’t usually a material associated with being environmentally friendly. But when it’s made from renewable biomass sources like vegetable oil and algae, it’s arguably more environmentally friendly than concrete, since the processes and production associated with the manufacturing of concrete contribute significantly to global carbon emissions. In 2018, French construction technology researcher Zoubeir Lafhaj told Youris, a European innovation news website, that bioplastics are the future of 3D-printed construction.

UL’s new guidance document on 3D-printed construction, UL 3401, indicates that any polymeric-based additive manufacturing materials—in other words, plastic—“shall be tested in accordance with applicable standards in the installation code.” This could include standards like NFPA 275, Standard Method of Fire Tests for the Evaluation of Thermal Barriers.


Six years ago, the global engineering firm Arup unveiled striking designs for steel construction joints made by a 3D printer. The metallic gray joints resembled the patterns seen in cross-sections of bone, with smooth and

organic curves standing in stark contrast to their mostly symmetrical, hard-lined, cast-molded, and soldered counterparts. The 3D-printed joints were also about half the size of the traditionally made joints, yet they could carry the same structural load.

“By using additive manufacturing we can create lots of complex individually designed pieces far more efficiently,” says Salomé Galjaard, who designed the joints for Arup. “This has tremendous implications for reducing costs and cutting waste. But most importantly, this approach potentially enables a very sophisticated design, without the need to simplify the design in a later stage to lower costs.”

However, safety concerns exist around 3D printing with metals. Because the process often generates combustible dust, the 2021 edition of NFPA 1, Fire Code, includes new requirements aimed at mitigating this threat. “The code is addressing these issues by requiring listed equipment, safe dust collection and management processes, and safe use and handling of any associated hazardous materials,” says Kristin Bigda, an NFPA technical lead, about the code update.


Perhaps the best example of 3D-printed construction knowing no boundaries is the use of a living material to create structures and structural elements. Artists and researchers alike have touted the potential for mycelium, a filamentous fungus that grows to form mushrooms, to make 3D-printed buildings.

Eric Klarenbeek, an artist from the Netherlands, has used mycelium, which he calls a “living glue,” combined with ground-up straw, to 3D print a number of objects, most notably a chair in 2014. “This chair is really a metaphor for what could be made with this technique of 3D printing a living organism and then have it grow further,” Klarenbeek told at the time. “It could be a table, a whole interior, or even a house.” —A.V.

Top photograph: Getty Images