Abstract
Construction and demolition waste represents a significant environmental challenge, accounting for up to 25% of Norway’s total waste. This study establishes benchmark values for construction site waste and associated greenhouse gas (GHG) emissions across eight building typologies, based on data from 76 Norwegian projects (2014–2025) and a life cycle assessment methodology to calculate emissions from waste handling and replacement materials. On average, projects generated 40kg/m2 of waste and 55kgCO₂eq/m2 in GHG emissions. There are marked differences in waste amounts, recycling rates, and GHG emissions across building typologies, likely related to differences in building requirements and construction methods. Material production accounts for 73% of total emissions. Benchmark comparisons with national datasets show that emissions from construction waste are significantly underestimated in existing models. Lack of high-quality construction waste data hinders more detailed benchmarking. These findings highlight the need for improved data collection, harmonised digital reporting systems, and integration of construction methods and material data. The benchmarks provide a foundation for more accurate waste planning, policy development, and sustainability certification. Future work should include rehabilitation and demolition projects and adopt a holistic approach to environmental impact assessment across the construction value chain.