Hemp: A Four Letter Word for Sustainable Homes

Hemp is a wildly useful plant. However, it’s often gotten a bad rap, confused as it often is with marijuana. While the two plants do share similarities, the main difference is that hemp doesn’t get you high. Instead, it serves an enormous number of practical uses — as a material for clothing, paper, and even pet food. And now, it’s drawing attention (again) as a building material for sustainable housing.

Centuries before the birth of the United States, hemp was used in multiple ways, including as a building material. One of the oldest homes in Japan, dating from the 1600s, incorporated hemp in its construction — and that home still stands.

For many years, hemp was a typical crop in the U.S. In the 1930s, however, concern over its connection to marijuana led to a government ruling banning hemp. Fortunately, those regulations have loosened, and there’s now a growing interest in the many uses for the plant.  One of those uses is “hempcrete,” which blends hemp into a lime/sand mixture that’s healthier and more durable than standard concrete. Builders are testing it as a replacement for more typical (but toxin-heavy) construction elements like drywall and insulation materials. Findings show that hempcrete better vents CO2 from homes, handles heat and cold more efficiently (which saves energy), and is more durable and fireproof.

Several hempcrete homes are currently being showcased in Pennsylvania, in a push to gain more awareness among builders and sustainably-focused homeowners. There are still some hurdles to be overcome (zoning regulations for one), but hempcrete offers real promise as a sustainable construction material.

We recently helped to produce a TV series for Japan’s public broadcaster, NHK. “Rock, Paper, Timber” reveals ingenious methods for building living/working spaces that are more sustainable. The full episode features some other cool stuff we think you’ll like. Please have a look and let us know what you think.

-Cindy Grogan

Photo: Unsplash.com