Plantd Makes Homebuilding Materials Out Of Carbon-Capturing Hemp

CEO Josh Dorfman (middle) with two Plantd employees in a hemp field.

The co-founders of the Durham-based startup Plantd, Josh Dorfman and Huade Tan, have cracked the code for how to make strong, sustainable homebuilding materials without using wood. The secret? Hemp.

Hemp fiber is three times stronger than wood fiber, it grows faster and in more places, and best of all, as it grows it captures three times the amount of carbon as trees. So using hemp as a homebuilding material is not only a better alternative to builders, but it’s better for the environment too, said Dorfman.

Earlier this year, Dorfman—now Plantd’s CEO—was trying to figure out how to make more sustainable furniture materials for his furniture manufacturing company. That’s when he met his soon-to-be-cofounder Tan, Plantd’s CTO, who was working as an engineer for SpaceX, where they were researching fast-growing biomass alternatives to trees that could take carbon out of the atmosphere.

While hemp can be made into multiple materials, Dorfman and Tan decided to initially focus their carbon-removal business on making sustainable materials for the housing market, because of the large market opportunity and the shortage of traditional building materials like wood and concrete. 

“Even though our internal motivation is to solve climate change, we’re not asking builders to buy because that’s what we care about,” Dorfman said. “We’re offering them a better building product for the same price.”

Plantd is a semifinalist for one of NC IDEA’s $50K SEED grants. The startup is currently in the prototyping phase using a lab in Durham, and they plan to launch in 2023. They are focusing their initial launch on the North Carolina housing market and already have agreements with NC farmers for hemp production as well as letters of intent from builders in the state, Dorfman said. 

After NC, they will expand into Texas and the Orlando/Tampa housing market, the latter of which is the second-largest housing market in the country. Due to the fact that hemp can grow in many more diverse climates than trees, Plantd doesn’t have to ship all of their materials from one large factory to all of their markets. Instead, they can just set up a hemp factory in Florida, for instance, whereas wood would have to be shipped—a significant cost savings.

A Plantd hemp board, which is three times stronger than a wood board.

Plantd’s secret sauce—what Dorfman calls their “core innovation”—is that they are creating their own machinery to make the manufacturing process much more cost-effective than the current wood manufacturing process. Tan is a former engineer at SpaceX, which has been experimenting with similar manufacturing innovations over the past decade, Dorfman said. 

Plantd’s machines apply pressure to compress hemp boards in a different way that requires less heavy machinery. Also, hemp doesn’t need to be dried out—whereas wood is 50% “wet”—so they don’t need massive drying machines.

One advantage of having a lighter manufacturing process is that they can set up multiple subsidiary production lines close to their markets rather than relying on one centralized factory, which is standard for wood manufacturers. Smaller-scale production also makes maintenance costs lower and makes it cheaper to get a replacement part because parts are more widely available, Dorfman said. 

Plantd’s production tactics are exactly why they are able to offer hemp-based building materials that are the same price as those made from wood, Dorfman said. 

“Unless you have a novel manufacturing approach, it’s very hard to make the unit economics work to be able to compete with wood manufacturers,” Dorfman said. 

Moreover, because hemp is stronger than wood, a thinner hemp board can provide the same level of strength, which makes the entire construction process lighter and means boards are better able to withstand extreme weather, Dorfman said. Plantd also tested their boards and found that they provide the same level of moisture resistance as wood boards, so when it rains they don’t swell any more. 

Seeking a $100M prize

Plantd is going after the $100 million Gigaton Carbon Removal prize, which is a four-year competition announced by Elon Musk and XPRIZE in April 2021. The winning startup must come up with a low-cost solution that removes at least 1,000 tons of atmospheric carbon per year, model their costs to remove a million tons a year, and show a plausible path to remove a gigaton per year in the future. 

The International Panel on Climate Change estimates that 10 gigatons of atmospheric CO2 need to be removed per year by 2050 in order to keep global temperature rise under 2 degrees Celsius, according to the XPRIZE website. Dorfman said Plantd’s long-term goal is to tackle climate change using their carbon-removal solution to completely eliminate concrete, steel and wood from the construction process. 

“We can’t solve climate change unless we develop ways to take carbon out of the atmosphere,” Dorfman said. “We cannot just electric-car ourselves away from the problem. No one needs to pay us just to take carbon out of the atmosphere. We’re going to go change an industry by offering builders a better product at the same price, and in the process, we feel like we have an opportunity to scale a business that can help save the planet, too.”