Building materials in a circular economy

This research analyses the supply chains of manufactured building materials used by the residential housing industry so as to assist the housing industry in reducing greenhouse gas (GHG) emissions. Understanding the structure of building-material supply chains is essential for policy development seeking to reduce carbon intensity of new material choice and use in the housing industry. This will require the housing industry to rely less on newly made materials and more on the reuse, recycling and resource recovery of ‘used’ materials, which will involve an efficient and responsive ‘used’ materials markets. The designers of the two presented case studies recognised the issues that challenge movement towards circularity, specifically the financial cost of planning for building disassembly at the end-of-life; and how costs restricted the choice of lower-carbon materials and alternative construction methods. The recovery and reuse of building materials is difficult in the absence of regulation; underpricing of landfill; the absence of markets; poor waste-stream data collection; and designs that do not support material end-of-life recovery. The research identified a number of key areas for policy development, including building materials data collection and analysis; incentivising disassembly and reuse; regulation to support housing-system decarbonisation, including supporting reuse, rethink, repurpose or remanufacture; tilting investment flows towards CE outcomes; expanding the pool of people with a knowledge of CE education, training and skill development; and establishing housing-industry supply-chain councils to develop supply-chain decarbonisation plans.