Mind the gap: How stakeholder awareness shapes energy retrofit effectiveness in public daycare centers

Energy efficiency retrofitting (EER) has emerged as a critical strategy for reducing energy consumption in existing buildings. However, the realized performance of retrofit projects is influenced not only by technical factors but also by the decision-making behavior of stakeholders with differing levels of expertise. This study quantitatively evaluates how stakeholder perspectives—classified as non-expert, semi-expert, and expert—affect the selection of energy conservation measures (ECMs) and the resulting energy savings in retrofit projects. Empirical data from 241 public daycare centers in South Korea, retrofitted between 2021 and 2023, were used to compare ECM combinations and performance outcomes across stakeholder groups. Given that these facilities operate under strict budgetary and administrative constraints, and energy costs are not directly borne by end users, stakeholder decisions exert an even greater influence on project outcomes. The analysis shows that non-experts tended to prioritize visible and comfort-oriented improvements, semi-experts emphasized practical installation considerations, and experts optimized ECMs using the energy-saving coefficient (ESC) methodology. Simulation results indicate that expert-driven strategies achieved the highest energy reduction efficiency at both the building and city scales, yielding average heating and cooling energy savings of 39.4%. The findings demonstrate that inconsistent or perception-driven decision making by non-experts and semi-experts can reduce the effectiveness of retrofit projects. This study highlights the importance of stakeholder-informed design support systems and introduces a practical, Excel-based decision-making tool to facilitate more effective retrofit planning. The results emphasize the need for policy frameworks that encourage expert-guided or stakeholder-assisted approaches to maximize the efficiency of retrofit investments.