The pavilion comprises approximately 10,000 bricks that were developed from a mixture of chopped up corn stalks and mushrooms. Amy Barkow/Barkow Photo
Designers conduct extensive testing to incorporate bricks ‘grown’ from mushrooms into a pavilion for the MoMA PS1 Young Architects Program in New York City.
August 12, 2014—This summer, people who visit the towering pavilion in the courtyard of MoMA PS1, a contemporary art institute in the borough of Queens in New York City, shouldn’t be surprised if they start feeling a bit hungry as they explore the structure. After all, the pavilion comprises approximately 10,000 bricks made from mushrooms—a new building material that required extensive testing as part of the project design.
David Benjamin, a principal of the New York City-based architecture firm The Living, designed the pavilion for the 17th annual MoMA PS1 Young Architects Program—an invitational competition that challenges emerging architects to develop innovative and experimental projects. The competition guidelines invite the designers to consider the principles of sustainable design in their entries. An affiliate of the city’s renowned Museum of Modern Art, MoMA PS1 awards each year’s winning architect a stipend to take his or her design through to construction. The temporary installation is then open to the public in the MoMA PS1 courtyard during the summer months. This year’s project will be open until September 6.
Known as Hy-Fi, a name that plays on the scientific term hyphae—the branching structures of a fungus—the 41 ft tall pavilion appears as three conjoined chimneys or cylinders rising from a 46 ft wide base. Three A-frame-style doorways allow visitors to enter the pavilion and look up through the 14 ft diameter openings at the top of each chimney. Benjamin partnered with the New York City office of the global engineering firm Arup to develop the project design. “We were really looking for a shape for the structure that would both test the performance of this new [mushroom-grown] material and demonstrate that we can make really interesting space with this material,” Benjamin says.
Ecovative, a Green Island, New York-based material sciences firm and pioneer in using mushrooms to make such things as packaging material, manufactured the bricks for the project. The process involved combining chopped up corn stalks with mycelium (masses of hyphae) from mushrooms. The mixture was then packed into brick-shaped molds and stored in the dark for approximately 10 days. As the mushrooms grew, they bound the mixture together, forming solid bricks with characteristics similar to Styrofoam.
The pavilion’s timber framing system comprises a central tripod
structure and three A-frames. Inside the pavilion, visitors can see
the sky through the 14 ft diameter openings at the tops of the
chimneys and through strategically placed portals.
Amy Barkow/Barkow Photo
“One of the main things that we proposed for this project was that we could make a structure that starts from nothing but earth and returns to nothing but the earth,” says Benjamin, whose firm is committed to incorporating living biological organisms into its projects. “We were very interested in the fact that this is a building material that comes from crop by-products, so it doesn’t use a lot of high-value materials. We were also very interested because this mushroom material can biodegrade after it’s done being used.”
Before the bricks could be incorporated into the project, however, engineers had to understand their properties. After standing on the bricks to determine that they could hold their weight up to the desired height, engineers sent the bricks to the Robert A.W. Carleton Strength of Materials Laboratory at Columbia University for compression, sheer, cyclical load, and tension testing. Matt Clark, P.E., an associate structural engineer for Arup, says that the studies revealed that the bricks are 200,000 times less stiff than steel. “The mushroom bricks certainly aren’t a replacement for steel, structural concrete, or clay bricks because they’re very flexible, more like polystyrene,” he says. “But they were sufficient for this project.”
Wind was a concern, so engineers collaborated with BMT Fluid Mechanics, an international wind engineering firm with an office in New York City, to determine how much wind they could expect during construction and while the pavilion is standing. Studies indicated that the structure had to be stable enough to withstand wind speeds up to 65 mph. The biodegradable bricks were also subjected to accelerated aging tests to understand how they would weather in the sun and rain. “They were tested for the equivalent of a two-year period even though the pavilion will only be up for about two months,” explains Shaina Saporta, P.E., a structural engineer for Arup. “The strength of the bricks did not degrade over that two years, which was interesting and good news for us.”
Once the brick testing was completed, the architects incorporated that data into a 3-D model to finalize the pavilion’s geometry and determine the arrangement of the bricks. Benjamin says the algorithms were run several times throughout the process to ensure that the bricks were arranged in the most efficient manner. Only full-, half-, and quarter-sized bricks were used for the structure, so everything had to fit together without the need for other brick sizes. “In a conventional wall when you get to the end, you might cut a brick to fit,” Clark explains. “But we had to work with full, half, and quarter bricks, so each course of bricks was laid out on the computer, and then that arrangement was translated to the site.”
The engineers also analyzed different types of mortars in hopes of finding a biodegradable one for the project. “We looked at quite a few mortars, including some all-organic and wheat-based mortars with agricultural waste in them, and found quite a few that seemed strong,” Saporta says. “But we weren’t confident enough in the durability of any of those mortars over a two-month period that tends to have a lot of thunderstorms.” Ultimately, the team selected a more traditional heavy-lime mortar because of its proven performance and ease of construction. “We had access to the courtyard for only three weeks for construction,” Clark explains. “So we had to get all of these bricks built very quickly, and the union labor that was hired for the brick work needed to use a mortar that they are familiar with.” The team found out it had won the project in February and construction commenced at the end of May.
Architects and engineers used computer modeling to achieve the
pavilion’s geometry and determine the most efficient arrangement
of the bricks. Arup
Construction began with the erection of a framing system comprising three timber A-frames that are wrapped with steel hoops at strategic points for stiffness. “All of the framing was necessary to deal with high wind speeds,” Clark notes. “If this was indoors, we probably could have built it without framing because the dead weight is quite manageable. It would have been like building an arch, where you use formwork during construction, and then you take the form out.” Just as with a traditional project, the brick masons used string lines as guides and laid the bricks from the bottom up, securing them to the frame with bolts. While most of the bricks were made with mushrooms, the reflective bricks at the top of the structure were produced by custom forming a new daylighting mirror film invented by the St. Paul, Minnesota-based multinational conglomeration 3M Company.
The timber components were founded on screw piles, while the bricks at the base were founded on a bed of hempcrete—a biocomposite form of concrete that contains hemp fibers—to keep the bricks from decomposing too quickly. “The courtyard has poor drainage and is known to flood during big thunderstorms, so using something similar to concrete next to the ground is very sensible to keep all of the organic work up slightly higher,” Clark says. “We want the structure to decompose, but we want it to do that at the right time.” An organic penetrant was applied to the mushroom bricks to protect them from rain water through the summer. Once the pavilion is closed, it will be deconstructed and the bricks will be transported to a site where they can decompose.
Since construction was completed in June, the mushroom bricks have held up well even though a portion of the structure had to be temporarily roped off following strong storms, Clark says. Visitors have been eager to touch the bricks and take photos of them. The design team hopes the project will draw similar enthusiasm from industry professionals and encourage them to consider the possibilities of using organic materials in the built environment.
“We want to open up this question of what new kinds of materials are out there—both those that can be manufactured by living organisms and others that haven’t been explored before—and how can they be used to make a structure or building,” Benjamin says. “We’re facing some major challenges in terms of resources, the planet, climate change, equality, and increasing demand for materials and energy with the large world population. We think this is just one of many possible ways to engage with those problems and push what might be possible.”