Why Marginal Gains Matter: Reducing Construction Waste to Cut Costs and Carbon in UK Housebuilding

Building cost-effective homes that comply with stringent environmental regulations remains a significant challenge for the UK housebuilding sector, particularly for social housing providers. In the context of net zero targets and reducing embodied carbon, this study examines opportunities to minimise material waste and associated impacts. Using an inductive mixed-methods approach, the research began with a literature review to establish baseline waste rates across key material streams. It then analysed material usage data from three completed housing developments, comparing estimated quantities with actual orders and spend to identify discrepancies between assumptions and real-world outcomes. To validate these findings, a controlled case study tracked the construction of a single four-bedroom home, enabling direct measurement of waste rates and assessment of cost and carbon implications at unit level. Results highlight a series of marginal gains achievable through improved estimating and procurement practices, which collectively offer potential for significant financial savings and reductions in embodied carbon when scaled nationally. For social housing providers, these efficiencies could lower build costs, support sustainability goals, and create opportunities to reinvest in additional housing delivery.