Improving Waste Management at Construction Sites—Evidence from a Comparative Study in Poland and Slovakia

Construction waste management remains a critical challenge for improving project efficiency and sustainability. Despite extensive research, there is still a lack of comparative and up-to-date empirical studies addressing both material and non-material waste across different national contexts, limiting the identification of optimisation priorities. This study addresses this gap by analysing construction-site waste in Poland and Slovakia. A mixed-method approach was applied, combining quantitative, qualitative, and comparative analyses based on a questionnaire survey conducted in 2024 among construction contractors. Respondents evaluated 34 waste factors using a four-point scale in terms of frequency and importance. The results indicate that errors and inconsistencies in design documentation represent the most significant and frequent source of waste in both countries (importance: 3.60 in Poland, 3.12 in Slovakia; frequency: 3.40 and 2.87). Other critical factors include excessive workload of employees, delays in construction processes, quality defects in executed works and damage to completed works. Differences were also observed, particularly in change management and stakeholder relations. The findings highlight key areas for improving waste management, especially in design coordination, communication, and workforce organisation, supporting the implementation of BIM and Lean Construction.