Assessing construction material waste in Egypt through stakeholder estimation

Abstract Construction and demolition waste (C&DW) remains a major sustainability challenge, particularly in developing countries where reliable empirical measurements of material losses are scarce. This study examines construction material waste in Egypt using a mixed-methods approach, primarily based on stakeholder perspectives, with supplementary validation from actual project records. A mixed-methods approach was employed, combining a structured questionnaire distributed to 250 professionals (113 responses) with validation using actual data from two bridge projects and one commercial building. Fourteen commonly used construction materials were assessed, with estimation indicating waste rates between 5% and 9%. The highest losses were reported for sand (8.56%), mortar (8.13%), and masonry (7.94%), while reinforcement steel showed comparatively lower losses (5.15%). Contractors and subcontractors were reported as the main contributors to waste generation, although both contractors and owners were identified as key actors capable of reducing waste. Respondents also indicated moderate awareness and slightly positive attitudes toward waste-related regulations. Participants estimated that improved site controls and enhanced management practices could reduce overall waste levels by approximately 27%. Despite limited project-based validation, the findings provide useful insights that emphasize the need for targeted improvements in resource efficiency.