Hempcrete: A Promising Building Material

The Cement Industry is One of the Primary Producers of Carbon Dioxide

The cement industry is one of the primary producers of carbon dioxide, a potent greenhouse gas. The primary production of conventional concrete has a footprint of 456 to 689 pounds of carbon dioxide per 1.3 cubic yards

One interesting alternative is hempcrete. JustBioFiber, a hemp-based modular block supplier, reports that its product sequesters 243 to 287 pounds of carbon dioxide per 1.3 cubic yards, based on the quantity of carbon-storing plant fiber used. Additionally, the blocks re-carbonate an additional 141 pounds per 1.3 cubic yards during the curing process. The company claims that their product also enhances the energy efficiency of buildings with its high insulating capacity-resulting in a 64 percent reduction of greenhouse gas emissions compared with building code standards. (source)

According to wikipedia, hempcrete is a low density material and resistant to cracking under movement thus making it highly suitable for use in earthquake-prone areas such as Northern California. Other advantages of hempcrete include: fire-resistant, pest-resistant, an excellent insulator, and fully recyclable.

What about building costs? Hempcrete is comparable to other building materials in cost. In other words, your expenses will likely be similar if you were to use more traditional building materials. However, if you look over the lifetime of the building, superior thermal performance may provide significant extra savings in the long-run.

What would help bring this promising building-material alternative mainstream? Legislation. Since 1970, all forms of Cannabis sativa L., including hemp, have been classified as a Schedule 1 drug under the Controlled Substances Act. This classification is grouping hemp, which has a THC level of less than .3%, in the same category as marijuana with a THC level ranging from 5%-30+%. In part, this is why you can buy hemp Lotions, hemp seeds, and other products that use the crop: other countries have recognized the difference, and allow for the commercial cultivation of hemp.

The Industrial Hemp Farming Act of 2017, if successful, will eliminate the controlled substance designation for hemp. This will make it easier for farmers around the country to grow the crop. This change may eventually help lower the cost of hempcrete as building materials become more readily available and innovation improves efficiency.

If you wanted to build a hempcrete house in Santa Cruz, could you? I posed this question to the County Planning Department, and the answer is yes, you can permit a hempcrete house. If you are interested in learning more, this website has useful information about the hempcrete building process as well as consultation services.