One of the oldest and most sustainable building materials of all time is staging a comeback: hemp. Now that several states have legalized the use of marijuana for some recreational and medicinal purposes, a big untapped market is emerging for cannabis to be used as a building tool.
Across America a grassroots effort is underway among builders, architects, material suppliers and farmers to renew this fledgling market. Mixing hemp’s woody core with lime and water produces a natural, light concrete that retains thermal mass and is highly insulating. No pests, no mold, good acoustics, low humidity, no pesticide.It grows from seed to harvest in about four months.