The Lower Sioux in Minnesota are Leading the Eco-Housing Game

This indigenous nation is use hemp to make houses, and will have the only hempcrete facility in the country

Hiya!

I’m always curious to see how people style their homes and think it’s boring when all the houses in a neighborhood look alike. One reason I love walking around my neighborhood is the variety of different-styled houses that line the streets — some are old craftsman or Victorian, some are modern and new, some are small, and some are huge. But now there’s a new category — eco-friendly.

Climate change forces us to rethink how we build structures and the materials used to create them. Concrete is by far the most commonly used material for construction today, but it also has a large carbon footprint. So, finding an alternative is not only ideal but necessary. Luckily, the Lower Sioux in Minnesota are doing what no one else is — producing hempcrete and using it to build homes.

The Hemp Plant

The hemp plant is often confused with its cousin, the cannabis plant. While similar in appearance, the hemp plant has less than one percent of Δ 9-tetrahydrocannabinol (THC), which is the compound responsible for the psychoactive effects the cannabis plant is known for. In other words, consuming hemp won’t get you high.

Not getting you high is about the only thing hemp can’t do, though. For starters, hemp fiber is biodegradable, elastic, lightweight, and stable. It could replace or at least significantly reduce the use of plastic — along with paper and cardboard, textiles, rope, cotton, fuel, and many building materials.

That’s just a few things we can do with hemp. So far, it’s estimated that there are at least 25,000 different uses for the plant. Beyond its product versatility, hemp is incredible for the environment, a nutritious food source, yields more than one harvest a year, and can grow in many climates. All of this makes the hemp plant practically magical.

Using hemp for textiles, fuel, and plastics would pave the way toward a more sustainable future. But even focusing on using hemp to implement one change, say replacing concrete with hempcrete, would give us some significant gains in the climate battle.

Hempcrete

Concrete results from mixing cement, fine and coarse aggregates, water, chemical admixtures, and mineral admixtures. It is the most widely used manufactured construction material worldwide thanks to its versatility, strength, abundance, and affordability. Unfortunately, producing concrete is responsible for around 4 to 5 percent of the worldwide total carbon emissions.

Comparatively, hempcrete is made using a mixture of mashed hemp stalks with water and lime, which creates an oatmeal-like paste that can be sprayed or poured into wall cavities or molds similar to concrete. It was once thought that hempcrete was as strong as concrete, but further research says its structural properties are more like fiberglass.

Still, after vigorous studies, hempcrete has proven to be a useful material for flooring, non-load-bearing walls, and roof insulation since it is lightweight and has good moisture buffering, thermal insulation, and acoustic properties. It’s also non-toxic and resistant to mold, pests, and fire — unlike many other building materials we use today, including concrete.

We’re not done yet, though. Regarding carbon emissions, hempcrete is one of the few carbon-negative materials. This is because the hemp plant absorbs more carbon from the atmosphere (while also cleaning toxins, including “forever chemicals” from the soil) than the entire process of making hempcrete and its application on construction sites emits.

Even more incredible, hempcrete continues to absorb carbon even after construction — meaning the material stores more carbon from the atmosphere throughout the building’s lifetime than was emitted during its construction. And since hempcrete is a bio-composite material, it can be recycled once the building’s lifetime ends.

Considering all this and more, One might think the construction industry would jump on utilizing this material. Some countries have, especially throughout Europe, but as it turns out, commercial hemp was banned in the United States until the Farm Bill in 2018 — and was just recently approved as a residential building material.

Despite its very recent approval, there’s hesitancy around producing hempcrete. Farmers don’t want to plant hemp crops without facilities to process the hemp stalks, but processing companies don’t want to spend the money on the necessary equipment without guarantees they’ll have the hemp to process. Further, most American contractors are unfamiliar with hempcrete.

All of this means that hempcrete is a scarce resource in the United States and is usually imported from Europe — and therefore, it’s also expensive. As a result, hempcrete is currently used mainly as a building material for affluent people with the financial means to contract a green home. Jody McGuinness, the executive director of the Hemp Industries Association, summarizes:

“It’s accessible to people with wealth, who can afford to build a bespoke house. It’s not accessible to the general public.”

But a small indigenous community in Minnesota is working to change that.