Straw adds strength in UM green building class

Daniel Mears
The Detroit News

Historically, houses made of straw have not fared well, but University of Michigan Art, Design and Environment Professor Joe Trumpey and his students intend to make history.

University of Michigan students take part in a Green Building class, constructing a stray bail dwelling at the UM Campus Farm at Matthaei Botanical Gardens in Ann Arbor.

“It’s the first official U of M building in Ann Arbor that is student-built that I am aware of, period,” he said.

Situated on the student-run UM Campus Farm at the Matthaei Botanical Gardens, Trumpey’s students have been studying about green building since January and the class concludes with the straw bale construction. “This building will give the farm a needed social space where they can have class meetings and dining events such as U of M farm-to-table dinners.”

Art and design student Livvy Arau-McSweeney, right, cuts some straw to put in wood supports for a window sill.

Straw bale buildings have been around since about the 1800s. “As soon as John Deer and others invented the baling machine out on the plains, they were building sod homes; it was easy for them to look at these big bricks and think, oh, man, these look bigger and better than stacking sod,” Trumpey explains in a YouTube video.

“Big box beams go on top of the straw bales and then are connected down to the foundation with long rods that are tightened, compressing the walls, making them really firm and stout, “ Trumpey explains. “The roof does not sit on the straw walls but on post and beams that are built inside.”

Three coats of earth, plaster and straw are then put over the straw bales with the final coat having lime putty in it to make it more water proof.

Art and design graduate Jack Hyland, 22, said, “Building the straw bale house makes you think about alternatives to building and construction and connecting us to our natural environment.”

University of Michigan environmental engineering student Natalie Ritter, 23 and art and design student Charlotte Cardon, 19 work on putting on the second coat of straw, clay, water and shorter pieces of straw over the straw bale walls.

Applying coats of mud and straw by hand over the walls of straw, University of Michigan art and design student Charlotte Cardon, 19, wipes her brow, adding another layer of dirt to her face.

“I’ve always have been really interested in this stuff since I was a kid so I think this is the perfect thing I was looking for but never really expected it.” That being said, Cardon goes on, “I never thought in a million years I would be doing this in an art school.”