University of Maine 3D-Prints Prototype House with Natural Materials

The University of Maine's BioHome3D was printed with a material made mostly of wood fiber.

Green Building Advisor’s Scott Gibson reported that the University of Maine’s Advanced Structures and Composites Center has printed a prototype house with bio-based materials. The 600-square-foot structure, called BioHome3D, was unveiled at the university’s Orono campus in November. All the components of the house—roof, walls, and floors—were printed with a material composed of wood fibers and bio-resins, making the building fully recyclable.

What makes BioHome different
Concrete, a material with high embodied carbon and very low R-values, seems to be the most common material used to print houses. BioHome3D addresses both of those shortcomings with its wood-fiber mix. The house is not so much insulated after the fact as it is actually made out of insulation—wood fiber and blown-in cellulose. The Composites Center says R-values can be customized for the needs of a particular site.

“Many technologies are being developed to 3D print homes,” ASCC Executive Director Dr. Habib Dagher said in a prepared statement. “But unlike BioHome3D, most are printed using concrete. However, only the concrete walls are printed on top of a conventionally cast concrete foundation. Traditional wood framing or wood trusses are used to complete the roof. Unlike the existing technologies the entire BioHome3D was printed, including the floors, walls, and roof. The bio-materials used are 100% recyclable, so our great grandchildren can fully recycle BioHome3D.”

Concrete is an especially touchy subject for a growing number of builders. Worldwide, the production of cement, the binder in concrete, is responsible for an estimated 8% of all greenhouse gas emissions. Buildings that use a lot of concrete are front-loaded with a heavy carbon penalty that can offset the amount of carbon saved by higher operating efficiencies. In the short term, experts like Chris Magwood of the Endeavour Centre believe that lowering embodied carbon in building materials is more important than lower operational carbon when it comes to slowing down global warming.