Edinburgh Napier University

  This study uses material flow analysis to estimate the material stocks and flows and associated upfront embodied carbon emissions for gravity building structural systems in the United States. Seven scenarios that align with the shared-socioeconomic pathways are conceptualized and used to estimate floor space and structural material demands through 2100. These scenarios consider aggressive, moderate, and low adoption rates of timber-based structural materials. Under all scenarios, total floor space is projected to increase to a maximum upper-bound of 202% (162,187 m2) between 2020 and 2100. The results indicate that the associated increase demand for structural materials cannot be met solely by urban mining of decommissioned buildings. Assuming present-day carbon emissions intensities of structural materials, the average upfront embodied carbon intensity for gravity superstructures in the building stock decreases from 49 kg CO2e/m2 in 2020 to 29 kg CO2e/m2 in 2100 under the scenario with aggressive adoption of timber-based systems.