Hybrid LCA for Construction Materials: An Application of the Australian Industrial Ecology Virtual Laboratory

Buildings and construction materials account for one third of global greenhouse gas (GHG) emissions during their life cycle. While direct emissions from the operation of buildings are well understood, embodied emissions of construction materials require further attention because they constitute a significant additional proportion of emissions. The Integrated Carbon Metrics (ICM) project comprehensively quantifies embodied GHG emissions relating to the built environment in Australia. In this project, we develop a novel hybrid life cycle assessment (LCA) methodology that harmonises data from different scales and sources by combining top-down and bottom-up approaches. Specificity and completeness of carbon footprint calculations is achieved by integrating different methods and data such as process-based LCA, Material Flow Analysis (MFA), and Input-Output Analysis (IOA). The methodology will inform development of a suite of custom-designed calculation tools that track embodied carbon flows along the production and supply chains of materials and products at various spatial scales. We describe the development of a comprehensive database of embodied carbon LCI data for building materials and products based on the Australian Industrial Ecology Virtual Laboratory (IELab), the most comprehensive, environmentally extended input-output database available for use in Australia. The IELab combines economic and environmental data at an unprecedented level of detail, which significantly enhances our analytical capabilities in developing the hybrid LCA methodology. We have quantified carbon footprints of about one hundred construction and building materials and elements. In this contribution we focus on concrete as a case study. The ICM project is funded by the Cooperative Research Centre for Low Carbon Living (CRCLCL) in association with several industry partners.