Using hemp in building insulation could make structures greener, create jobs, and be a profitable industry

It’s a fairly niche product now, but a new study from Georgia Tech engineers suggests insulation made from hemp fibers could be a viable industry in the U.S., creating jobs, a manufacturing base, and greener homes and buildings at the same time.

Making the switch could slash the impact of one of the biggest sources of greenhouse gas emissions: Buildings account for roughly 1/5 of emissions globally. By some estimates, using hemp-based products would reduce the environmental impact of insulation by 90% or more.

The Georgia Tech researchers’ work, published this month in the Journal of Cleaner Production, is one of the first studies to evaluate the potential for scaling up U.S. production and availability of hemp-based insulation products.

“Existing economic modeling studies were mostly limited to data on purchase price, finding that hemp insulation is more expensive than conventional installations. We wanted to go a different route, modeling from the industry’s perspective,” said Arjun Thangaraj Ramshankar, lead author of the study and an environmental engineering Ph.D. student.

“The lack of studies also means lack of data, so our methods not only focused on economic modeling, but also on, how do you address the lack of data and still develop a fair model?”

Machine learning helped the team of civil and environmental engineering, public policy, and mechanical engineering researchers fill those gaps and uncover a promising market opportunity—despite fairly expensive raw hemp fibers, an underdeveloped supply chain, and still nascent demand.

Bottom line: Hemp insulation is a viable industry in the U.S., the researchers found. Sustaining it, though, will require a fairly high volume of sales and more of the product produced in the U.S.

Industrial production of hemp has picked up substantially since it was legalized by Congress in 2018. The fibers from the fast-growing plant can be turned into a variety of products, including clothing, rope, and biodegradable plastics. Construction materials using hemp—concrete, plaster, and insulation, among them—are gaining popularity as a way to reduce the carbon impact of buildings, especially in Europe.

Hemp insulation can directly replace fiberglass products in residential and commercial buildings, but it currently costs about twice as much.

Senior co-author Joe Bozeman said the team’s study suggests well-placed incentives could jump-start the industry, helping subsidize production capacity while demand grows.

“This could be a really mutually beneficial marketplace for everyone,” said Bozeman, assistant professor in the School of Civil and Environmental Engineering. “We get less embodied carbon in buildings, a new industry, new jobs, and then there’s a lot of opportunity for technological advancements on the back of this market viability.”

Bozeman also said marrying the emerging market for hemp insulation with the shortage of housing in the U.S. could mean real opportunity to address two issues simultaneously.

“We could have a really, really interesting dynamic: Some of the newer houses could have less embodied carbon by using this hemp insulation, which could also jump-start the market,” he said. “This is something federal or state legislation can address.”

Along with graduate student Kelly Farmer and mechanical engineering Assistant Professor Akanksha Menon, Ramshankar and Bozeman performed what they called a techno-economic analysis to assess whether there’s opportunity to develop a market for the insulation. It’s an approach that will have broader uses in Bozeman’s lab—including projects on reducing the carbon footprint of concrete, recycling lithium from electric vehicle batteries, and reusing nutrients and filtering out “forever chemicals” like PFAS in wastewater.

“We used hemp insulation as our material for this study, but the broader goal was developing a framework for any alternative that you’re considering,” Ramshankar said. “With this method, you can assess economic viability for any material being considered as a potential alternative.”