A Life-Cycle Approach to Investigate the Potential of Novel Biobased Construction Materials toward a Circular Built Environment

Conventional construction materials which rely on a fossil-based, nonrenewable extractive economy are typically associated with an entrenched linear economic approach to production. Current research indicates the clear interrelationships between the production and use of construction materials and anthropogenic climate change. This paper investigates the potential for emerging high-performance biobased construction materials, produced sustainably and/or using waste byproducts, to enable a more environmentally sustainable approach to the built environment. Life-cycle assessment (LCA) is employed to compare three wall assemblies using local biobased materials in Montreal (Canada), Nairobi (Kenya), and Accra (Ghana) vs. a traditional construction using gypsum boards and rockwool insulation. Global warming potential, nonrenewable cumulative energy demand, acidification potential, eutrophication potential, and freshwater consumption (FWC) are considered. Scenarios include options for design for disassembly (DfD), as well as potential future alternatives for electricity supply in Kenya and Ghana. Results indicate that all biobased alternatives have lower (often significantly so) life-cycle impacts per functional unit, compared to the traditional construction. DfD strategies are also shown to result in -10% to -50% impact reductions. The results for both African countries exhibit a large dependence on the electricity source used for manufacturing, with significant potential for future decarbonization, but also some associated tradeoffs in terms of acidification and eutrophication.