Hemp: The Building Material Of The Future
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At a glance, the hemp industry in the United States appears to be booming.
In just a few short years, the country went from having fewer than 10,000 acres licensed for hemp planting to more than half a million. Sales of CBD products rose from essentially nothing to $6.5 billion in 2020. BDSA and other industry analysts predict the industry will reach about $16 billion by the year 2023.
But with wholesale prices waning and the threat of industry-killing federal regulations, many people believe the true potential of hemp is less about cannabinoids and more about the industrial uses of the cannabis plant, including as a textile, a component of bio-plastics, a wood alternative and, perhaps most importantly, as a building material known as hempcrete.
“CBD isn’t going to go away, but the fiber plant is going to be what sustains the hemp industry in the future,” says architect Bob Escher.
“It’s not the quick, sexy money that CBD is, or that medical and adult-use cannabis are, but the fiber side represents the opportunity to take a bite out of things like the automotive industry, building materials, plastics and textiles,” says hemp entrepreneur Cameron McIntosh. “You’re knocking down industries that will make medical and recreational cannabis and CBD look miniscule.”
And with hempcrete, specifically, the benefits are not just economic, but in helping to create a more sustainable and environmentally friendly world. In light of ongoing concerns about climate change, hemp could be a game-changer.
“Maybe this really is the material that the green industry has been waiting for,” Escher says. “I’m convinced it is.”
It’s important to understand what exactly hempcrete is, because the name “hempcrete” is a bit of a misnomer. It doesn’t actually have much similarity to concrete.
Hempcrete — “more accurately described as hemp lime bio-composite insulation,” says McIntosh — is a material that can be used for walls or insulation in homes and other buildings. It’s made by mixing hemp hurd, which is the inner woody core of the stalk, with a natural lime-based binder and water. It’s non-structural, so buildings still need a traditional foundation and frame, and it cannot be used in situations where it would be in constant contact with ground water.
When done properly, the benefits almost sound too good to be true. It’s resistant to mold, mildew, rot, pests and fire, and it’s an excellent thermal insulator.
“The wonderful thing is that it has a high level of technical performance that is only rivaled by the fact that it’s a sustainable, renewable, non-toxic, healthy material to live in,” McIntosh says. “It’s not a gimmick that we’re using just because it’s hemp.”
McIntosh started his Pennsylvania-based company, Americhanvre, a licensed and insured installer of hempcrete, mostly focused on the retrofit market, in June 2018.
He tells people conservatively they can see a 30-60% reduction in their heating and cooling costs with hempcrete insulation, though he says some in the industry say it’s as high as 80%, depending on the climate and the design of the building. Hempcrete produces a thermal envelope everywhere it’s applied, eliminating the seams and layers that allow leakage and movement.
“And it’s damn-near fireproof because you’ve encapsulated all of the organic material, including the frame, in most cases, with this material and the lime binders, so it does not smoke and it will not ignite when exposed to an open flame,” he adds.
Pamela Bosch is one of only a handful of people in the United States living in a hempcrete residence. She hopes one day to be able to use her Bellingham, Washington, home as way to promote sustainability.
For Bosch, it was the environmental benefits that drew her to hempcrete, but she says she loves the aesthetics and the feel of the home.
“When you’re in it, it’s really obvious that it’s a better way to build,” she says. “The acoustics are so much better. You can feel the difference and hear the difference when you walk in the door. It sounds like a lot of hype, and especially in the cannabis world, there’s a lot of that going around. But it really does bear out.”
She also says hempcrete works particularly well in a wet climate, because of the way it handles humidity.
“In fact, it can get totally saturated and then dry out and it won’t mold,” she says.
There are drawbacks to hempcrete, of course. For example, the way it’s manufactured and installed right now, at least in the United States, is very expensive and labor-intensive. McIntosh says it’s about 20% more expensive than using traditional building materials. Another drawback is the six to 10 weeks required for wet hempcrete to cure, before a lime plaster can be applied (“traditional old-world lime plastering, not stucco from the hardware store,” McIntosh says). Ready-made hempcrete blocks or panels could be a solution, but nobody’s currently making them in the United States.
But most of the downsides of hempcrete are related to building codes and the supply chain, rather than the material itself.
“One of the things I’m hoping to see is that the gap between sustainability and affordability begins to close,” McIntosh says.
Hempcrete is not a new material by any means. It’s been used extensively in Europe and elsewhere for decades. But with the United States finally developing a domestic hemp market once again and sustainability becoming a bigger selling point for many Americans, it’s slowly gaining some traction.
Bob Escher, an architect in Vermont, was introduced to industrial hemp by his son in 2017. His firm, Escher Designs, specializes in custom second homes and small commercial work. Working with hempcrete “was the exact opposite of anything I’d ever considered,” he says.
But he began learning about the material and making connections, eventually joining up with Kelly Thornton of Left Hand Hemp, who was teaching a hempcrete class, and Eric McKee, who wanted to build an out-building on his property in Denver and was looking for an architect.
“It was perfect timing and destiny that the three of us would get together,” Escher says.
In October 2017, they completed a 320-square-foot building called the WNDER Workshop. Unlike most hempcrete buildings that look like adobe, the WNDER Workshop was a post-and-beam structure. It was also the first permitted hempcrete building in Denver.
When it was featured as part of a tour of hemp buildings during the NoCo Hemp Conference, Escher says he was amazed at people’s reactions.
“Everybody was interested in hemp, but they hadn’t seen a building like this before,” he says. One man called it “historic” and Escher initially dismissed the comment. After all, he’d built custom homes all over the Northeast for more than 30 years; the WNDER Workshop was “just a shed.”
“It really struck me because what was historic about it was that it created a genre that hadn’t been done before, and it was taking hempcrete as a building material to a different level,” he says.
McIntosh went through a similar revelation when he launched Americhanvre and built a small hemp house on wheels, in conjunction with the architecture firm Coexist Build, that would visit a variety of trade shows across the country, including the Cannabis World Congress and Business Expo in New York and the Farm Progress Show in Illinois, the largest farming trade event in the country.
“Like many in the hemp industry, I went from being a cannabis enthusiast to a hemp activist sort of overnight as I stuck my head into the world of hemp lime and hempcrete building systems,” he says.
Although their initial hemp projects drew ample interest, Escher and McIntosh say there’s a lot that needs to happen before hempcrete can become a viable commercial-scale building material.
McIntosh says there’s plenty of farmland and plenty of farmers interested in growing hemp for fiber, but the processing power doesn’t exist yet and it’s unclear how much demand there will be from end users.
“It’s that tri-fold issue where we’re all waiting on each other,” he says. “You need processors and farmers and end users, and we’re trying encourage all three of those pieces to come together. I think the processing aspect is really the linchpin.”
Like Kevin Costner’s character in Field of Dreams, one can almost hear the whispering cornfields: “If you build it, they will come.”
Escher says there are three critical components missing right now: education, infrastructure and certification.
He believes building codes and full certification are about five years away — a time frame similar to McIntosh’s projections. Escher’s telling his associates and colleagues to spend the next five years on the education angle, learning how to work with hempcrete. It’s not something that can be learned solely from reading books; people need the hands-on experience. And each region will have its own nuances when it comes to the hemp-lime mixture and the interactions with other materials.
Start with small projects, he advises. And if you’re going to build, build as best you can.
“If you go too fast, you make mistakes,” he says. “In a new market like this, any failure or bad press will affect the growth. And it’s going to happen, without a doubt. But let’s let it happen to a garage or a small barn, not someone’s house in a nice, fancy neighborhood.”
The educational component also needs to happen with state and local officials, many of whom still associate hemp with marijuana. It’s a conversation most hemp advocates have already had dozens of times, explaining the difference between the two varieties of Cannabis sativa L., but they’ll have to keep illuminating people until hemp-based products are fully accepted into the mainstream. Escher says it helps to speak with city officials in terms of meeting their sustainability initiatives and reducing energy costs for homeowners.
“Believe me, you can’t beat city hall,” he says. “As much of a cliché as that sounds, you can’t beat city hall, but you can get them excited to work with you.”
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The Long Play
The explosion of the cannabis industry — both in terms of hemp and marijuana — could eventually bode well for the hemp-based building materials sector.
According to McIntosh, the hurd comprises 65-85% of the cannabis plant, depending on what it was grown for, but right now, most stalks are simply discarded or composted after harvest.
“If we can monetize that 85% of the plant, it’ll be a no-brainer for these fiber processors to open up,” he says, referring to the decorticators — machines that separate the fiber from the hurd — and other processing equipment needed to scale up the hemp-based building materials sector.
While CBD has garnered the most interest, thus far, from investors and entrepreneurs — and helped pave the way for the relegalization of hemp — industrial products are gaining more attention.
“Anyone that I’ve spoken to that is spending a lot of money doing CBD knows in the back of their mind that fiber is the long play and has plans for their entry into the market based on certain indicators,” McIntosh says.
Linda Delair, a sustainable business consultant based in California, says she believes commercial buildings in the United States will be able to utilize hempcrete in the near future. It gives hope to the idea that the cannabis dispensaries of the future will not only sell cannabis, but be, at least partially, constructed from cannabis.
Of course, that will also require domestic producers of hemp fiber.
“Who wants to import that much hemp?” she says. “You want Minnesota and other states to grow enough hemp for their own beer bottling. If you look at the Adnams brewery (in the UK), they don’t have any heating and cooling. They don’t need it. It stays warm in the winter and cool in the summer. It works really well, so I would love to see any dispensary built out of hempcrete.”
An ongoing project
Bosch has been working on the various stages of her “Highland Hemp House” for about four years now. Part of it was built as an addition and part of it was a retrofit to her 1960s home, tucked in the far northwest corner of Washington state.
She’s had a number of subcontractors work on the house, but she’s been the only person who’s overseen every step of the project.
She says it’s been a process of “learn as I go, teach as I go, preach as I go.”
It began with her looking for a non-toxic insulation, but she couldn’t find anything that fit the bill. She eventually found a hemp-based batt insulation used in the UK, which then led her to hempcrete. In 2015, she went to Europe, rented a car and drove around the continent, visiting as many hemp buildings as she could. She saw old cobblestone homes that were being revamped with hempcrete to turn drafty, uncomfortable buildings into livable spaces. She visited an airplane hangar that stored antiques and artifacts inside hempcrete inner chambers that naturally moderated the humidity. She toured a brewery built with hempcrete that could maintain the proper temperature with little to no heating and cooling.
After reading a book written by the well-known hempcrete expert Steve Allin, she attended one of the author’s workshops and Colorado, and he helped her build a small hempcrete shed on her property, kicking off a project that would “become my life,” she says.
“I certainly didn’t need a bigger house,” she says. “In fact, I needed a smaller house, but I wanted to make it an educational facility, so it needed to be not just a hippie out-back shack. It needed to be a respectable building with a good design.”
She had to import the hemp hurd from the Netherlands, and even with shipping costing as much as the materials, she said it was affordable, though the various engineering, construction and insurance costs added up quickly.
“There’s no reason for it to be more expensive,” she says. “It’s just because we’re inexperienced. We don’t have a track record in this country of pre-industrial structures.”
She has run into a few challenges with the house, including a problem related to the lime-based render on the outside, but many of the issues can be chalked up to inexperience and permitting hurdles.
Although the project is ongoing, she says it’s been a rewarding experience and it’s helping to fulfill her missions of healing the building industry and healing the environment in the midst of devastating climate change. But it’s also a mission the rest of the country needs to join.
According to McIntosh, the new building industry represents about 30% of the carbon emissions in the United States.
“As far as I’m concerned,” Bosch says, “we need real solutions quickly.”
The future of hempcrete and other hemp-based building materials is bright, even if its mainstream surge is still several years away.
“It’s going to change the construction industry because there are many ways that hemp can be integrated into insulations and blocks and plastics and roofing and fabrics and fibers,” says Escher. “You name it, hemp can do it.”
In 2019, Escher helped form the U.S. Hemp Building Association to support and advocate for the growing niche and to bring hemp-based building materials to the forefront of the American construction industry.
Also in 2019, the first U.S. Hemp Building Summit was held in Ketchum, Idaho, bringing nearly 300 people from all walks of the hemp and construction fields together, including architects, engineers, contractors, interior designers, painters, masons, advocates and potential investors.
Escher says it was exciting to see such a wide-ranging group of professionals participate in the summit, because it’s crucial to have people from each sector know how to integrate hemp-based materials into modern construction. Understanding hemp-based building materials is one part of the equation, but having trained plumbers, electricians and dozens of other specialists is equally important.
In a house built with hempcrete, “the hemp part is probably 30% of the house,” Escher says. “You still have to build everything else.”
The coronavirus pandemic derailed some of the momentum, just as it has nearly every industry in the United States. Like most events, the 2020 Hemp Building Summit shifted to a virtual format, scheduled for October 24.
Yet, investors, visionaries and entrepreneurs continue to push the industry forward one square foot at a time.
“We’ve really only just begun to get into these things and put American entrepreneurship and ingenuity to work,” McIntosh says. “Hempcrete is the low-hanging fruit, but there are also all these wonderful and amazing high-tech ways to utilize hemp that I think are going to explode onto the scene in the next 50 years or so.”