Building materials in a circular economy

This report is one of four projects examining how the transition to a circular housing economy could be implemented to provide sustainable housing. The transition to a circular economy (CE) from a linear ‘take-make-dispose’ economy, has become a widely discussed topic in both academia and industry since its introduction from policy makers such as in the European Union (EU 2018). Considering the unsustainable approaches within the sector, academics have highlighted that there is an urgent need to shift into a more sustainable framework, with a focus on implementing a CE approach (e.g. Munaro, Tavares et al. 2020; Norouzi, Chàfer et al. 2021; Núñez-Cacho, Górecki et al. 2018; Panteli, Kylili et al. 2018). The focus of the project is the flow of building materials into and out of the residential housing system. There is a temporal element to this research, as new construction adds new materials to the existing stock, while demolition creates a flow of materials out of the stock laid down in previous eras. From a circular perspective, demolition promotes only downcycling, whereas deconstruction retains value and in some cases, upcycling. All of the materials used to construct the existing housing stock are produced by manufacturing industries that emit greenhouse gases (GHG), and new construction is equally—if not more—GHG-intensive.