Tracing resource flows and reducing environmental impacts during construction: Assessment framework for on-site waste efficiency
Lea Hasselsteen Nielsen, Anders Damgaard, Aleksander P. Otovic, Harpa Birgisdóttir, Kai Kanafani
Abstract
The construction industry significantly contributes to global environmental degradation, including carbon emissions and waste generation. This study presents a novel framework integrating material flow analysis (MFA) and life cycle impact assessment (LCIA) to systematically assess and improve material and waste flows during the construction phase of buildings. The framework aims to identify inefficiencies, optimise resource allocation, and enhance waste management practices on construction sites. A case study of a multifamily residential building in Denmark demonstrated the framework's applicability and effectiveness. The MFA revealed significant inefficiencies, with approximately 136.3 kg of waste generated per built square meter, corresponding to 9.1 % of delivered materials being wasted due to over-ordering and improper planning. The LCIA results showed that enhanced material sorting and increased recycling efforts could reduce environmental emissions and resource depletion by up to 69 %. Practical strategies such as closed-loop recycling for concrete and take-back schemes for bricks and wood pallets demonstrated clear environmental benefits, including reduced landfill waste and lowered impacts from new material production. The data obtained through the framework identifies key areas for improving on-site waste management. By implementing detailed monitoring and analysis, stakeholders can reduce waste through better planning, inventory control, and material handling practices. The framework also provides insights into the best treatment methods for different types of waste, ensuring materials are reused, recycled, or disposed of in the most environmentally friendly manner. Additionally, the framework offers real-time insights on material use, waste, and handling, helping stakeholders make informed decisions to reduce overuse and optimise resource allocation. Identifying key materials for waste efficiency supports site-specific interventions that lessen environmental impacts and improve waste management. The actionable data provided by the framework ensures compliance with environmental regulations and certification schemes, promotes resource efficiency, and supports the transition to a circular economy.