Investigating Residential Building Materials in a Circular Economy: An Australian Perspective

Abstract

The circular economy plays a key role in the wider transition to a low-carbon built environment. Materials are critical in this transition, yet there is limited information about their current use in the built environment in many regions. This explorative study investigated circular economy in the Australian construction materials industry using a three-stage mixed-method approach. The first stage was to map actors and their practices and challenges related to material supply, use, and end of life. This involved 20 interviews with stakeholders and a workshop. The second stage was to assess key materials stocks and flows to identify the volume of the challenge through existing databases and consultation with industry stakeholders. The third stage was to understand the current state of material circularity at industry-leading examples. This was investigated through 13 interviews across two case studies, alongside site visits. These complementary research methods and stages provided findings into material circularity potential within the residential construction sector from both a macroperspective and a microperspective. The results included that new materials being used in construction are more than double the flow of waste out, showing that stocks of materials in use are growing rapidly but that data gaps are extensive. There was a focus on material reduction for cost-savings and sustainability, but there was significant opportunity for other circular economy principles, such as rethinking construction techniques. Further, in the context of a highly volatile industry, circularity requires a focus on material-specific institutional arrangements. The contribution to knowledge on construction materials and their supply chain provides fundamental insights that are required for the transition toward a circular economy, where the residential construction sector (not just in Australia but globally) would more readily reduce, reuse, recycle and recover resources, as well as being less reliant on virgin material use.