How the Lower Sioux Indian Community is building homes with hemp

MORTON, Minn. — Marijuana is newly legal in Minnesota, but its cannabis cousin, hemp, has had the green light for years. It's used in textiles, clothes, food and THC-infused edibles popping up all across the state.

But in the Lower Sioux Indian Community in southwest Minnesota, tribal members are using part of the plant as a building block for a better future.

It's called "hempcrete"—a mixture of hemp plus water and a binder that's extracted from limestone. Lower Sioux Hemp has built three homes and a shed with the material. Admittedly, project manager Danny Desjarlais says, the name is a bit deceiving because it's not like traditional concrete.

"You still have to frame the building with your traditional two by fours, two by six or steel beams or whatever you're going to frame the structure with," he told WCCO in a recent interview. "it still has to be framed with something other than hempcrete. Hempcrete is not structural, it's basically your wall insulation and that's it."

The part of the plant used is the inner stem, known as the hurd. Ground up it looks like wood chips and mixed together with the water and lime binder, it's thick and wet and takes weeks to dry out, which then transforms it into a durable building material. 

Then it's ready to insulate homes. The Lower Sioux Indian Community so far has found success using it, Desjarlais explained. He said hempcrete provides better insulation and can save a homeowner energy costs in the long run. And because it comes from natural ingredients, it's not toxic.

Hemp is also a carbon-negative crop.

"Everyone has kind of rallied behind hemp now," Desjarlais said. "Once we got our first structure built and they got to go inside and see it and touch it, now everyone is like 'I want a hempcrete house. Why weren't we doing this sooner?'"

Hemp was included in the U.S. Drug Enforcement Administration's list of controlled substances until 2018, and only recently was hempcrete authorized in U.S. building codes.

There are also supply chain limitations right now, like not enough growers or processors of the plant, said Earl Pendelton, former vice president of the tribal government. That hinders large-scale production of hempcrete for homes and other residential buildings, though advocates hope that changes so it's more widely used in commercial construction.

Pendelton first advocated for growing the plant and even before it became legal when the Lower Sioux Indian Community participated in a state pilot project to grow hemp in 2017. 

He saw how hemp could help meet a need—the reservation was short about 100 homes. And it would be a way to offer jobs in the community beyond the casino, a major employer. 

"It was about job creation. It's about our younger generation going to college and coming back with design and architectural degrees that can help really push this forward and keep the momentum that we started here," Pendelton said.

Hempcrete isn't unique to the reservation. It's been used to build homes in Europe in places like France and the U.K. But Desjarlais and his team will soon expand their work: The Minnesota Department of Employment and Economic Development awarded the Lower Sioux Indian Community a $1.5 million grant for a 20,000 square-foot campus on the reservation to grow hemp and process it to make hempcrete.

"It's like we're growing our own homes and we're putting our community members in these homes," Desjarlais said. "It's really rewarding."