Hemp's R-value beats that of concrete: roughly 2 to 2.5 per inch (based on the density) compared to 0.1 to 0.2 per inch of concrete. The compressive strength of hemp, however, is 1/20 that of concrete, so hemp shouldn't be used as a foundation or in load-bearing areas. Hemp's resistance to cracking makes it an excellent building alternative in earthquake areas.

Hemp: A Historic Building Material

Is it any wonder that hemp has been in demand as an easy-to-use, natural building material since Roman times? "A hemp mortar bridge was constructed back in the 6th century when France was still Gaul," the Times article states.

In France, hemp cultivation is legal, and the country has become the European Union's largest hemp producer. Across Canada, Europe, and England, hundreds of buildings have used hemp for wall and roof insulation. This includes a “Natural House” built by Prince Charles that uses sheep's wool and hemp insulation and is warmed by a wood stove.

In the U.S., the first modern hemp home was built in 2010 for Russ Martin, the then-mayor of Asheville, North Carolina. The 3,400-square-foot home has hempcrete walls that are 12-inches thick. The cost of each exterior wall was about $25 to $30 per cubic foot. At the time, you couldn't get hempcrete in the United States. It was illegal to grow industrial hemp because it comes from the cannabis plant. So the higher cost was partly driven by the need to import the raw materials needing from the United Kingdom. "Domestic production could cut the price tag in half," Anthony Brenner, of Push Design, told AmericanLimeTechnology.com. Thankfully, it is no longer illegal—but it will take some time for the U.S. hemp industry to grow and the costs to come down.

Growing Toward Self-Sufficiency

Meanwhile, in Quebec, Fay's home is nearly completed. The wood-framed house, with shou sugi ban window framing and hemp insulation, was designed with large windows facing south to bring in the sun. The home's thermal mass keeps the house cool in summer and warm in winter. A wood stove provides supplemental heat in winter and warms the water that runs through a heating system beneath the floors. No air conditioning is necessary during the summer. The house is solar-ready, but because Quebec electricity is so inexpensive, Fay says, they'll wait several years before hooking up the solar. They also plan to purchase an electric car.

"We're aiming to be as sustainable and self-sufficient as possible," she says. "We already have chickens and a rooster, fruit-bearing trees and shrubs, and a small garden. My husband takes care of the animals and grows mushrooms." A greenhouse will allow the couple to grow vegetables in the winter. Rainwater off the home's metal roof is used for plants. WaterSense low-flow fixtures in the kitchen and bath, and LED lights used in the evenings (as the windows bring in plentiful daylight) help reduce the couple's carbon footprint.

"We're working at changing our habits, too, like buying in bulk using our own containers, so we reduce the amount of plastic," says Fay, who makes her own soap and herbal medicines. "I had a daycare for 18 years and just retired. From this home, I want to teach children to discover a different way in which a home can be built and how to pick and enjoy fresh fruits and vegetables for pleasure and good taste. Nature is the solution."