Industrial symbiosis relationships in construction industry: a random forest regression analysis

Purpose The construction industry generates over one-third of global waste, highlighting the urgent need for more sustainable resource management practices. Industrial Symbiosis (IS), which facilitates the exchange of waste and by-products between industries, has emerged as a promising approach. This study aims to investigate the significance of IS relationships for the construction industry. Design/methodology/approach A pragmatic mixed-methods research design was adopted. Two rounds of qualitative Delphi interviews involving industry experts (28 interviews) were conducted to identify potential IS relationships, followed by a questionnaire survey of 104 construction professionals to evaluate their significance. The qualitative data were analysed using code-based content analysis in NVivo, while quantitative data were analysed using random forest regression. Findings The results validated 66 IS relationships relevant to the construction industry, of which nine were identified as highly significant. The most prominent relationships included material-based applications such as the use of fly ash in cement and concrete production, energy-based applications including biogas for on-site power generation and heat recovery for hot water, and water-based applications such as wastewater reuse for brick moulding. Originality/value This study contributes to theory by identifying construction-specific IS relationships and advances methodology by integrating Delphi techniques with Random Forest regression to evaluate industrial symbiosis opportunities in the construction sector.