Hemp: Next New Option in Building Components

Blain Brownell, FAIA, is an architect and materials researcher. He is also the Director of the School of Architecture at the University of North Carolina at Charlotte. According to an article published in Architect Magazine, Brownell’s research has helped him identify another building product, which he believes has the potential of revolutionizing and replacing concrete, steel, and even wood in some, not all, structural building components. The fourth building option is Hemp.

Hemp is the non-psychoactive form of the cannabis plant which has been utilized for years to make rope, insulation, bioplastics, and other industrial materials due to its strength and rapid growth. Until recently, hemp has remained a peripheral product — the most familiar of which is Hempcrete — in the construction industry. However, it is becoming an increasingly viable option for more common building elements due to developments related to its similarities to — and differences from — wood.

As is now widely appreciated, wood’s carbon sequestration capabilities — and its resulting favorable carbon footprint compared with concrete and steel — have helped lead to its increased use in building construction. However, the resurgence of interest in engineered lumber has raised renewed concerns about overharvesting and deforestation.

Like wood, hemp stores carbon. However, hemp’s rapid growth makes for a superior carbon-capture feedstock. Hemp can be cultivated in 90 to 120 days, 100 times faster than oak trees. The plant also sequesters four times more carbon than a similarly sized forest. Hemp absorbs more than 20 metric tons of carbon per hectare, and its ability to be harvested biannually effectively doubles this quantity.