editors note: This story initially reported that this was the first full-sized home made from hempcrete in Colorado, but one was also completed in Steamboat Springs.
Chad Theis has built plenty of homes using alternative materials, but nothing quite excites him like the prospect of his hemp house — one of the first full-sized house of its kind in Colorado.
“I’ve always been concerned with the environment and built some alternative material homes before, but I’ve been studying hemp for a while and thought if we could grow it in Colorado and transport it only 50 miles to the job site, it would be way more efficient than the other materials,” he said. “So the whole idea for this house was to use all local materials.”
Working as a CBD supplier for KindXtractor.com on the side, Theis has studied hemp and its diverse set of uses for years. But it wasn’t until recently that he could find enough locally processed material to build a home using hempcrete.
A sort of concrete substitute made from dried hemp chips, water and lime, hempcrete is not only breathable, promoting improved indoor air quality and consistent temperatures in the ’60s or ’70s, but it’s also noise-resistant, pest-resistant, mold-resistant, flood-resistant, and even fire-resistant.
Though other countries have been working with hempcrete as a modern building material for decades — today there are hundreds of homes and even apartment complexes in Europe and Canada that were built using hemp — only 50 full-size hemp homes exist in America, none of which are located in Colorado.
While this aversion to hemp in America can likely be attributed in no small part to hemp’s connection to marijuana, as many states turn over a new leaf in regard to marijuana, builders and farmers are beginning to take hemp seriously.
“The United States is 20 years behind with hempcrete,” said Kelly Thornton, the founder of Left Hand Hemp, one of the only hempcrete contractors in Colorado. “But people here spend all this money on houses that aren’t energy-efficient, they’re toxic, they don’t breathe, and they seal everyone in chemicals. So I don’t see why hempcrete can’t become more conventional.”
Recognizing its potential, even Senate Majority Leader Mitch McConnell put forth a bill to federally legalize hemp, which President Trump signed in 2018.
Not only can hemp grow from seed to harvest in virtually any non-arctic climate in about four months, because it grows so densely, it also naturally rids the soil of weeds, eliminating the need to use chemical fertilizers or pesticides.
Its deep root system also requires less water than many other industrial crops and actually improves soil quality. Countries like China even use hemp for erosion control.
Furthermore, according to the Canadian Hemp Trade Alliance Canadian, hemp is more profitable than most conventional crops, raking in profits of about $250 per acre as opposed to $30 to $100 for wheat.
At least part of hemp’s value is derived from its high versatility. According to a Popular Mechanics article from 1938, hemp can be used to make 25,000 different products. Today it’s even used in car parts, plastics, biofuels, and, of course, hempcrete. But while hemp cultivation has grown dramatically in the U.S. since Colorado legalized marijuana in 2014, the industry is still looking for something to jump start it here in the United States.
“I get calls and emails every day from people interested in hemp and hempcrete,” Thornton said. “The problem is that no one in America really has the right equipment to process hemp on a large enough scale, so you have to get it from Canada and Europe. That’s why we need the government to step up with subsidies.”
Because American companies have not yet invested in technology to properly process hemp for hempcrete, which requires a $2 million machine known as a decorticator, farmers have nowhere limited options for selling their crop, eliminating any incentive to switch over their crops. That, in turn, diminishes the incentive for a company to invest in a decorticator.
However, being in the CBD business, Theis found a grower in Boulder County who had created a makeshift decorticator capable of processing enough hemp for Theis’ 2,600-square-foot hemp home.
After contracting out labor to pour the foundation and frame the house, Theis, his two sons, aged 5 and 8, and his nephew Cole, who’s studying construction management at Michigan State University, mixed the hempcrete themselves and poured it into place using 2-foot wooden molds nailed to the frame. After they lightly tamped it down and waited 30 minutes for the hempcrete to dry, they would move the mold up and repeat the process.
Of course, being the first to take on a project of such scale in Colorado, there were plenty of bumps along the road. In all, it took the them almost eight months to pour all of the exterior walls, though Thornton said a larger and more experienced team could have completed the job in just two days — albeit at a higher cost.
Doing a lot of that labor as a family, Theis estimated that using hempcrete cost him 20% more money and 10% more time than using traditional methods. Much of that expense, however, will be covered in the long run by the home’s energy efficiency.
With the exterior walls now in place, Theis is currently coating them with a lime plaster that resembles stucco and matches the drywall used to construct the interior walls separating each room.
The final touches will be to add solar panels on the roof and a geothermal heat pump, at which point, Theis believes the house will be totally self-sufficient.
“We might even add power to the grid,” he added.