This study investigates the relationship between energy efficiency, green tax policies, and ESG (Environmental, Social, and Governance) performance within Vietnam’s construction industry. Using a structural equation modeling (PLS-SEM) approach, survey data collected from managers and key employees in 41 construction SMEs reveals that energy efficiency positively impacts environmental, social, and governance performance. Furthermore, green tax compliance strengthens environmental outcomes, although its direct influence on governance performance is statistically insignificant. The interaction between green tax and energy efficiency significantly enhances environmental performance, underscoring the importance of integrating financial and operational strategies. These findings contribute to the theoretical understanding of ESG by demonstrating the combined effects of technical and fiscal measures on sustainable business practices. Practically, they offer insights for policymakers and construction firms aiming to align corporate strategies with Vietnam’s national green growth goals and international climate commitments.