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  • Les briques de chanvre, une solution à la crise du logement

Hempcrete: a solution to the housing crisisEcology

Published 2 October 2023 by AQIC

MORTON, MINN. — Danny Desjarlais has worked in the construction industry for nearly three decades. In all those years, a house he's helped build this year stands out as his proudest achievement: a duplex made with the hemp plant.

The house, believed to be the first of its kind in Minnesota, is made with hempcrete, a material consisting of woody hemp stalks, limestone and water. When finished, it will provide emergency housing for members of the Lower Sioux Indian Community reservation in Morton.

"I've been on a lot of job sites and driven to a lot of job sites, and I never [before] felt emotionally attached to a job," said Desjarlais, hempcrete construction project manager for the Lower Sioux Community.

Desjarlais and others started the Lower Sioux Hemp Program to address housing needs on the reservation. They say hempcrete, an emerging material in the construction industry, could move home construction in a safer and more sustainable direction. The program includes farming hemp plants, manufacturing hempcrete and constructing houses.

More than half the Lower Sioux Indian Community's 1,000 enrolled members live on tribal land. Larry Swann, director of the tribe's Dakota Future lending institution, said there aren't enough houses for members who want to live there; according to recent federal data, the reservation is about 200 homes short.

The first hempcrete house is slated to be ready for occupants in December. The one-story duplex doesn't look much different from other homes, but the 12-inch-thick walls are made of hempcrete, which resembles small wood chips stuck together when dried and finished. It's used to fill in wood framing for the interior walls and then covered with lime plaster.

Desjarlais said his construction team used about 8,000 pounds of hemp and installed the hempcrete in three days. It normally takes about three to four months to build a house of similar size using traditional methods and materials, he said.

"I don't want to build any other way now. I only want to build with hempcrete," he said.

Hempcrete is a relatively new construction material that gained traction in the United States after the 2018 Farm Bill legalizing commercial hemp production. Several countries, such as the United Kingdom and France, have built structures with hempcrete for many years. It's resistant to fire, mold and pests.

Hemp, a fast-growing herb used for industrial and medicinal purposes, is from the same cannabis species as marijuana but has less THC — the active ingredient that causes a high.

Because of hemp's ties to marijuana, some community members have been skeptical about using it to build houses, said Earl Pendleton, vice president of the Lower Sioux tribal council. "People thought you could smoke the house," he said.

Pendleton said that after reading an article about "25,000 uses" for hemp, he learned more about it and picked up the idea of building with hempcrete. "It can save you money, it's healthier for the environment, and it'll cut down on mold, pests and fire," he said.

Joey Goodthunder, hemp coordinator for the tribe, is in charge of farming, harvesting and processing the hemp plants. About 80 acres of hemp are grown on tribal land and farm fields scattered across neighboring land. Mature plants are harvested about three months after seeds are planted, he said.