Opportunities for reducing greenhouse gas emissions of insulation materials in Canada after cannabis legalization
The risk of shifting the environmental burden of a building from the use phase (i.e. emissions arising from the generation of energy consumed during heating and cooling operations) to the production stage (i.e. emissions arising during the manufacture of construction materials and their installation) is particularly true for buildings that require a lot of insulation to reduce their operational energy consumption. This is the case for cold countries like Canada, where regions can experience more than 7000 heating degrees days (i.e. annual sum of the number of degrees that a day's average temperature is below 18°C). Energy efficiency, when attained, is typically reached by means of traditional insulating materials: fiberglass, rock wool, spray foam and cellulose. However, the recent legalization of Cannabis for recreational use in Canada may lead to new opportunities for alternative, bio-based insulating materials. Cultivation of Cannabis will produce in fact a large amount of wooden and fibrous materials as by-products. The same by-products from a plant of the same genus but lower (−)-trans-Δ⁹-tetrahydrocannabinol (Δ9-THC) content (i.e. hemp) have been used in recent years to produce insulation materials and their supply is expected to expand in Canada due to a recent deregulation for hemp growers. The objectives of this study are to: (1) evaluate the environmental consequences of substituting the current fleet of insulators with fiber-based panels and composite materials made from the wooden core of the Cannabis plant and a binder (e.g. hempcrete), and (2) understand whether an opportunity could arise in Canada to reduce the environmental impacts of the building sector using by-products of Cannabis grown for recreational use. Preliminary results from a Life Cycle Assessment (LCA) confirm that potential greenhouse gas savings can be attained if bio-based composites and fibers are used in insulative material products.