Hemp made inroads in the building industry during an exhibition of modern
housing designs and technologies in the nation’s capital.
Hemp-based building materials were among the select group of housing innovations on
display for policymakers and the public in mid-June 2023 on the National Mall in
Washington, D.C.
This year marked the first time that hemp had a presence at the Innovative Housing
Showcase, an outdoor event which the National Association of Home Builders (NAHB)
and U.S. Department of Housing and Urban Development (HUD) sponsor on the
national stage. 2023 was the showcase’s third installment; another is planned in 2024.
To me, having hemp products at this event was another indication that the budding
domestic hemp industry—active in earnest since the end of 2018 when growing the
plant became legal again in the United States after some 80 years of prohibition—is
slowly but surely expanding its reach in American culture and the economy.
Takeaways
The U.S. Hemp Building Association and insulation manufacturer Hempitecture
represented the hemp building industry at a three-day showcase of innovative housing
technologies in June 2023 on the National Mall in Washington, D.C.
This was the first time hemp builders exhibited at this event, now in its third iteration;
their presence gave the mainstream construction industry, policymakers, and the public
exposure to Earth-friendly hemp materials.
In conjunction with the showcase, two former U.S. Hemp Building Association
presidents briefed a committee of the National Association of Home Builders, a
showcase co-sponsor, on how hemp could be an economic driver in a new sector of the
building industry.
Participating in the three-day showcase was the U.S. Hemp Building Association
(USHBA), the leading advocate for the mainstream adoption of hemp-derived
components in the building sector. USHBA’s booth displayed samples of items like
hemp-lime—a cast-in-place insulation material (a.k.a. “hempcrete”)—and hemp-based
flooring.
“We’ve incubated a lot of our membership and a lot of our base in the hemp industry …
and now we want to go evangelize in the construction industry to where everybody can
say, ‘Oh, this is how we use [hemp building materials] in a project,’” USHBA President
Ray Kaderli told me at the trade association’s booth on June 9, 2023, the showcase’s first day. Establishing relationships with other building associations is a big part of the outreach, said Kaderli.
Also exhibiting was Hempitecture of Ketchum, Idaho, manufacturer of hemp-based non-
woven insulation for walls, floors, and ceilings. The company’s flagship product,
HempWool thermal insulation—an Earth-friendly alternative to traditional fiberglass batt
insulation—was not only shown at its booth, but also was featured in the walls of one of
the showcase’s prototype homes: the 540-square-foot accessory dwelling unit (ADU)
that Cypress Community Development Corporation (Cypress CDC) of Brooklyn, N.Y.,
built for the occasion. This unit had a portion of one wall cut out so that visitors could
see the HempWool, along with other wall components.
“We know that we can have a booth and talk about our materials, but it clicks a lot better
when people can see [them] inside the walls,” Tommy Gibbons, Hempitecture’s co-
founder and chief innovation officer, told me at the showcase on its first day. He said
Craig Savage, who oversees building technology and innovation for Cypress CDC, had
contacted Hempitecture to see if there was interest in collaborating for the showcase.
Cypress CDC constructed the small home to engage a national conversation about
federal disaster housing policy and workforce housing shortages.
National Spotlight
I attended the first two days of the showcase, which took place not far from the U.S.
Capitol Building. The weekend event attracted more than 20,000 visitors, according to
NAHB’s recap. The National Building Museum supported the showcase, hosting a
series of technical discussions.
Some 20-plus developers of novel and affordable housing solutions came together from
across the United States—I think there was one Canadian company as well—to draw
attention to their designs and technologies. Such advancements “have the potential to
increase housing supply, lower the cost of construction, increase energy efficiency and
resilience, and reduce housing expenses for owners and renters,” stated the organizers
in a release. Some exhibitors erected prototype homes on the mall, as Cypress CDC
did, which visitors could enter and check out up close.
Among the non-hemp exhibitors that caught my eye were Azure Printed Homes of
Culver City, Calif., which utilizes 3D printing technology and recycled polymers to
produce ADUs, backyard studios, and homes; PathHouse of Portland, Ore., which
builds housing modules using timber extracted via restoration forest-management
practices; and WaterPlantir, maker of a modular, scalable septic treatment system for
residential and small businesses that comes in a refined planter design.
A smaller number of trade groups like the Structural Building Components Association
participated, and multiple government organizations had table set-ups, too, including
HUD, the Federal Emergency Management Agency (FEMA), and U.S. Department of
Energy (DOE).
Innovation Breeds Opportunity
USHBA’s showcase participation came about through Jean Lotus, the trade
association’s secretary. She also is editor of HempBuild Magazine. DOE selected Lotus
as one of the 2023 innovators whom it is supporting under its Incubating Market-
Propelled Entrepreneurial Lab (IMPEL) initiative which Lawrence Berkeley National
Laboratory in Berkeley, Calif., implements. This project aims to help to bring innovative
building technologies to market. Lotus’s project deals with fire-resistant, hemp-based
cladding. DOE invited Lotus to attend the showcase, which then morphed into the
association’s presence, said Kaderli, who runs the Hemp Build Network. He also is
founder of the Triple P Fund, a real estate investment firm for building affordable
housing in San Antonio using sustainable materials like hemp-lime. Working USHBA’s
booth with Kaderli and Lotus was Kaderli’s daughter Anna.
When HUD Secretary Marcia L. Fudge visited USHBA’s booth on the showcase’s first
day as part of her tour of the exhibits, Kaderli and Hempitecture’s Gibbons discussed
hemp building materials with her. (USHBA posted a video of the interaction at its
Facebook page.)
Kaderli, during his time in the nation’s capital, also met with members of Congress as
part of a lobbying fly-in in cooperation with the Global Hemp Association. “We had some
very good, attentive feedback from the legislators,” he said. He told me he articulated
USHBA’s support for language in the next federal farm bill that would clarify sections on
hemp in the previous farm legislation from 2018.
The goal is to make it less burdensome on American farmers from a regulatory
standpoint who grow varieties of hemp strictly for their fiber and grain—as opposed to
cultivating hemp types to yield their cannabinoids: those substances that may have
therapeutic and psychoactive effects when ingested. It is the fiber from the plant’s stalk
that is the raw material for hemp building materials. The fiber comes in two forms: bast
fiber, the quite-strong sinewy strands on the outer part of the stalk which are a
component of products like HempWool; and hurd, the stalk’s woody interior which is an
ingredient of hemp-lime.
Rapport and Trust
As with USHBA, Hempitecture’s showcase presence came about through its
relationship with DOE, said Gibbons. “We found out we would be invited here through
the Department of Energy … to represent them on behalf of HUD,” he said. DOE has
sponsored Hempitecture product research and Gibbons currently is a fellow in the
Innovation Crossroads program that DOE’s Building Technologies Office funds at Oak
Ridge National Laboratory in Oak Ridge, Tenn. The fellowship provides resources and a
network for the company to develop its products and expand their production and
distribution, according to Gibbons’s LinkedIn page.
“What our company and products need is greater awareness among the construction
community,” said Gibbons when I asked him what he hoped would result from the
showcase. “I don’t think that happens overnight. You don’t necessarily build a rapport and a trust relationship as a supplier with consumers immediately, but I think over time,
the more they see us supporting innovative housing showcases like this, … that’s good
for us.”
When Hempitecture opened its production facility in February 2023 in Jerome, Idaho, it
became the first manufacturer of “bio-based” insulation products in the United States.
(The federal government defines bio-based products as commercial or industrial goods
“composed in whole or in significant part of biological products, forestry materials, or
renewable domestic agricultural materials, including plant, animal, or marine materials.”)
The company utilizes the fiber of American-grown hemp for its products; processor IND
Hemp of Fort Benton, Mont., supplies the fiber. Hempitecture also offers AcoustiBatt
acoustic insulation and PlantPanel, a rigid continuous insulation to eliminate thermal
bridging. PlantPanel was on display at the company’s table, next to HempWool.
Mr. Hemp House of Indianapolis also was scheduled to exhibit, and I was looking
forward to visiting the company’s booth and learning about its products. However, owner
Christopher Penn, who, like Lotus, is a 2023 IMPEL innovator—for work on his hemp-
based “GaiaCrete” insulation material—had to pull out of attending due to the sudden
deterioration of his father’s health and his father’s subsequent death. “I had worked so
hard in preparation for the housing showcase,” Penn told me in an email
correspondence after the showcase. He continued, “Family is everything. My dreams
had to be put on hold.” I hope that the organizers will invite Mr. Hemp House back to the
next showcase.
Mr. Hemp House is “a sustainable housing innovation company that aims to
revolutionize the way we think about the health of buildings,” states the company’s
website. Its flagship product, GaiaCrete, is its version of hemp-lime. GaiaCrete can be
cast in place, formed into blocks (GaiaBloc), bricks (GaiaBrick), panels (GaiaPanel),
and various trims, moldings, casings, and other options, states the website. Mr. Hemp
House also is developing a “GaiaWool” insulation for walls, roofs, and floors and has a
concept for exterior “GaiaSiding.”
Survey Says
I surveyed showcase exhibitors as I walked around the booths and housing structures
to gauge their level of interest in hemp building materials. Jan Thoren, president of
NanoArchitech in Gilroy, Calif., told me that she has experimented with using hemp hurd
with the company’s NeuSkyns—nanoceramic composite coatings and solid building
material—but had not used hemp in any building project yet. She showed me a sample
she created of hemp hurd sandwiched between two thin ceramic tiles—think ice cream
sandwich—and also a tile with hurd mixed right in with the ceramic material. NeuSkyns
are designed as replacements for common cement. They make walls non-toxic, mold
resistant, fire-proof, and strong enough to withstand hurricane-force winds, according to
the company’s website and marketing placards.
Katie Copenhaver, Ph.D., who was staffing Oak Ridge National Laboratory’s booth, said
she works with hemp “on a smaller scale in terms of material development.” She’s a researcher in the sustainable manufacturing technologies group at the lab’s Hardin Valley Campus in Knoxville, Tenn. “Our [focus] is partnering with companies, helping them push their technology over the finish line, and doing it in a more efficient, lower carbon, more sustainable way,” she said.
Her activities support incorporating discontinuous natural fibers (chopped fibers several
millimeters in length), including from hemp, into existing polymers like thermoplastics to
replace synthetic fibers in them and meet, if not surpass the polymers’ existing
performance. Her group also is looking into spinning natural fibers into continuous
composite strands that can be overlayed in tows on materials to add strength to parts in
specific areas, she said.
“I am pretty natural fiber-agnostic,” said Copenhaver. “Whatever I can get, I will put it in
plastic, but hemp, in particular, I think is kind of at the forefront in the U.S. … I think a
huge applications space is in automotives.”
Some exhibitors still seemed not to know much, if anything, about hemp building
materials, let alone the hemp plant. Others were familiar and interested in the materials,
but thought it was too early to embrace these products since they did not think they
were readily available yet.
During my conversation with Savage of Cypress CDC, he said he’d like to see hemp be
a component of a new type of Earth-friendly structural insulated panel (SIP). Such a
panel doesn’t exist on the market today, he said. SIPs are used in residential and light
commercial construction, according to the website of the Structural Insulated Panel
Association. The panels comprise an insulating foam core sandwiched between two
structural facings, which typically are oriented strand board (OSB).
“Today, a SIP is made out of all the bad stuff … with resins in it that are petrochemicals.
The foam is urethane foam which is entirely petrochemical-based. So, although it fulfills
all of the building science functions that a wall or a roof or floor needs to fulfill, what a
SIP is made of is horrible in terms of our environment,” he said.
An ideal SIP would feature structural facings comprised of magnesium oxide material,
along with hemp-lime—or something similar—on the inside, said Savage. “I wish they
would create a foam out of it,” he said when discussing hemp-lime. “Create that foam
and put it in the ‘ice cream sandwich’ that is a SIP panel. I’d be really happy.”
Magnesium oxide is “carbon-neutral” (meaning its production and use do not release
any net new carbon in the atmosphere), fire-resistant, waterproof, insect-proof, and
stronger than OSB, said Savage. “There is nothing wrong with it that I can find yet. In
the past what was wrong with it was quality assurance and quality control. Coming from
China, you couldn’t depend on what it was.” However, large American suppliers of
building materials now are starting to sell magnesium oxide, he said. “It has a future, I
think that is undeniable,” he said.
The inaugural Innovative Housing Showcase took place in June 2019 and the second
one was in June 2022. The event has grown in scope each time. While the 2023
showcase was the first with hemp, the National Mall previously had hosted a builder
skilled in using hemp materials: In March 2022, hemp-lime builder Cameron McIntosh,
co-owner of Americhanvre Cast-Hemp in Allentown, Pa., brought the “Hemp House on
Wheels” to the National Mall as part of the “Ag on the Mall” event held in conjunction
with National Agriculture Day on March 22, 2022. McIntosh drove the tiny, mobile model
hemp home there in support of the National Hemp Association which was exhibiting. He
teamed with Coexist Build of Blandon, Pa., in 2019 to produce the Hemp House on
Wheels; he has traveled with it thousands of miles to parts of the United States so that
people can view a hemp-lime structure up close and personal.
A Big Deal
In conjunction with the housing showcase, former USHBA Presidents Bob Escher and
Jacob Waddell on June 9, 2023, gave a talk entitled “Hemp: The Economic Driver for a
New Sector of the U.S. Housing Industry” to NAHB’s Construction Liability, Risk
Management, and Building Materials Committee during NAHB’s spring leadership
meetings. The committee reviews new technologies for the organization. “That is a big
deal,” said Kaderli of the presentation. “It is one thing for the hemp community to be
talking about construction. It is yet another for the construction industry to be talking
about hemp.”
I saw both Escher and Waddell at different times at the showcase. Escher, an architect
in Dorset, Vt., was USHBA’s founding president and was the architect of the first
permitted hemp-lime structure in Denver. Waddell now runs the Hemp Building Institute
(HBI) which he established in Nashville. The institute’s mission is to bring natural
building materials and sustainable building practices to affordable housing.
“NAHB was interested in the topic of hemp as a building material and was referred to
Bob Escher. We contacted Bob and invited him to present to the committee, and he
brought Jacob into the conversation,” said David Jaffe, NAHB vice president, in a
statement the association provided explaining how the briefing came to be. The talk was
“very well” received, he said. In a subsequent release posted at NAHB’s blog, the
committee stated that it would “continue to work with the US Hemp Building Association
and the Hemp Building Institute to educate itself on this emerging building product.”
Escher told me in an email correspondence: “When the NAHB contacted me, it was
obvious that this presentation needed to focus on how hemp-based building materials
will be the economic driver for a NEW sector in the U.S. housing industry, and more
importantly, how it will create high-level jobs and careers.” He pointed out that on the
hemp-lime homes his firm is designing, the hemp installers are considered more than
just subcontractors. “They are ‘professional’ consultants (equal to a structural engineer
or interior designer) and are at the table working directly with me and the owners in the
early planning stages of the project,” he wrote.
Waddell said he viewed the briefing as “a major step into broader conversations” with
NAHB and its members. “As the HBI tries to promote the use of hemp building materials
in affordable housing, it is important that the established building industry works with
us,” he told me.
Decarbonization
The federal government, through agencies like DOE, is pumping billions of dollars into
advancing plant-based building materials to supplant traditional, often-toxic construction
components derived from petroleum and natural gas. One of the main drivers is to
“decarbonize” the building industry, meaning radically reduce the amount of carbon
dioxide (CO2) that it releases into the atmosphere. I have heard hemp advocates say
more than 30 percent of the world’s CO2 emissions today come from the building
industry.
Officials speak of reducing the construction sector’s “embodied carbon,” meaning the
CO2 released in the production of a building, including the transportation of materials to
the construction site and their disposal at the end of the building’s lifecycle. There also
is the desire to bring down significantly “operational carbon,” the amount of carbon
emissions from a building’s ongoing operation (e.g., its lighting system, heating, air
conditioning).
Some scientists believe that current levels of atmospheric carbon—a portion of which
they attribute to human activity—are too high and detrimental to the Earth’s climate and
environmental balance. It would be better to restore greater amounts of carbon back in
the soil and see more carbon sequestered in plants, they say. Whether one believes
that there is a climate emergency, or one just wants to be a sound steward of the
environment, hemp advocates say the plant, along with building materials derived from
it, offers numerous Earth-friendly benefits.
Hemp is a renewable resource, meaning the plant grows quickly and American farmers
can reap the benefits of its harvest each year. It also is a sustainable crop since
cultivating, harvesting, and processing the plant can occur without unduly depleting or
burdening the environment, say advocates. For example, hemp does not require the
use of toxic fertilizers or pesticides to grow, they say.
Savage of Cypress CDC described the appeal of hemp building materials to me in this
way: “My role in this company is to look at materials and create assemblies that make
sense,” he said. The hemp plant captures and holds carbon as it grows and then any
subsequent building material derived from it—when produced using low-intensity, low-
heat processes—retains the carbon, he said. “That product becomes basically a carbon
sync that will hold that carbon for the life of my house. … That is called ‘now carbon.’ …
I want to capture that ‘now carbon’ and … not let it get into the atmosphere,” he
explained. Savage is the former senior editor and publisher of The Journal of Light
Construction.
Building materials made with hemp also are durable, non-toxic, fire-resistant, and mold-
resistant, among their attributes, say advocates.
Durable, Vapor-Permeable Material
Take hemp-lime, for example. In its basic form, hemp-lime comprises tiny pieces of
hemp hurd, along with water and lime as the binding agent. When mixed together,
hemp-lime has an oatmeal-like consistency. Builders cast hemp-lime around a structural
wooden or steel frame since it is a non-structural, non-load-bearing material and
requires reinforcement with structural elements. (That’s why the hemp industry is
moving away from calling it by its old name “hempcrete,” since the name is misleading,
implying that it is a straight-up replacement for concrete.) Builders can also form hemp-
lime into blocks or panels or other shapes, but the same applies.
Once dried, hemp-lime becomes a durable, stone-like material. Because it is vapor-
permeable, hemp-lime is an excellent regulator of the humidity and temperature inside a
structure. This makes any hemp-lime building quite energy efficient, advocates say.
Hemp-lime also is resistant to insects and rodents. It will not rot over time like other
insulative materials, they say. A wooden frame covered by hemp-lime is protected from
rotting, too, they say.
USHBA’s efforts led to the International Code Council, the leading global body for model
building codes and safety standards, in September 2022 approving hemp-lime for
inclusion in the 2024 International Residential Code. This will make it easier for local
building departments in the United States to review plans for permitting its use in
homes.
As part of its educational outreach, USHBA is launching Hemp Build School to bring
together those interested in hemp building materials with builders experienced in using
them. There are courses designed for builders who want mentoring and for
homeowners seeking guidance on a building project with hemp. “We want to make sure
that everybody who wants to try this gets the love and support so that their project is a
success,” said Kaderli.
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