Beyond net-zero carbon and the built environment for Agenda 2050 through environmental responsibility and strategic green decisions for sustainable cities

Purpose This study examines the impact of environmental knowledge and environmental values on sustainable project success (SPS), as well as the mediating role of green purchase intention (GPI) and the moderating effect of environmental responsibility in enhancing SPS. Design/methodology/approach We adopted a quantitative methodology to analyze a cross-sectional survey of 640 construction professionals using Partial Least Squares Structural Equation Modelling (PLS-SEM) to test the proposed model. Findings The findings demonstrate that environmental knowledge and environmental values significantly improve SPS, with R2 = 0.71, which accounts for 71% of the variance of SPS and highlights the strength of these relationships. Further, GPI mediates these relationships, with indirect partial mediation effects for environmental knowledge (VAF = 51%) and environmental values (VAF = 53%) on SPS. Further, environmental responsibility moderates these relationships, with moderation effect sizes of f2 = 0.21 for environmental knowledge and f2 = 0.25 for environmental values, emphasizing the critical role of governance-driven environmental responsibility in strengthening behavioral translation mechanisms toward improved sustainability outcomes. Originality/value The originality of this study lies in contributing to the Theory of Planned Behavior (TPB) by empirically validating a contextually grounded moderated–mediation mechanism linking environmental knowledge and environmental values to SPS through GPI and environmental responsibility. Our study offers a theoretically refined and practically relevant sustainability framework by explicating behavioral and governance drivers within construction projects in a developing economy.