Out of the Woods Greensulate insulation 

board is “grown” from mycelium-injected 

agricultural waste.
Courtesy Ecovative Design Out of the Woods Greensulate insulation board is “grown” from mycelium-injected agricultural waste.

Gavin McIntyre got his first glimpse of the potential for using mushrooms in building materials when he would hike in the woods and see how mycelium—the vegetative part of the fungus—bonded with wood chips and trees.

That fascination continued when he was an engineering student at Rensselaer Polytechnic Institute (RPI) in Troy, N.Y., where McIntyre and his friend Eben Bayer grew mushrooms under their dorm room beds. While at RPI, the duo developed a process using mycelium to bond insulating particles, which they called “Greensulate.”

After graduating, they co-founded Ecovative Design, a Green Island, N.Y.–based company, in 2007. Ecovative focuses on developing natural, sustainable composite materials that can replace chemically produced plastics and foams. Ecovative’s initial operating capital has come primarily in the form of grants from agencies such as the EPA and the New York State Energy Research and Development Authority.

In essence, Ecovative “grows” its products by injecting mycelium into agricultural waste products, then places the mix into a mold where it expands and fills the mold in about a week.

McIntyre, Ecovative’s chief engineer (Bayer is CEO), claims that his company’s products require 10 times less energy to make than plastics and foams, emit eight times less carbon dioxide, and are compostable at the end of their life cycles.

McIntyre tells Builder his company is concentrating currently on producing “EcoCradle,” its mushroom-derived protective packaging material that is viable as a substitute for Styrofoam and other packaging products with heavier carbon footprints. Consequently, Ecovative doesn’t have the manufacturing capacity yet to mass produce its Greensulate insulation board, although he says Ecovative is planning to bring out that product sometime next year.

“We’ve met all of the compliance testing and have installed the product in buildings in the Northeast,” he says, adding that manufacturers have been testing Greensulate for various uses, including acoustical. McIntyre says the product is both VOC and aldehyde neutral, is mold and moisture resistant, and has an R-value of 3.6 per square inch. Its cost can’t be fully determined until Ecovative finds a manufacturing partner, but McIntyre notes that his company’s packaging products are being made at “cost parity” with more conventional materials.

Ecovative is also working on a mycelium-derived high-stiffness alternative for medium-density fiberboard, which already has met the specifications of the California Air Resources Board. McIntyre says this product would target the furniture and cabinet industries, and could go into production sometime in 2013.