Phase Change Materials in Residential Building Walls: A Systematic Investigation and Evidence-Informed Decision Framework for 3E Assessment

Phase change materials (PCMs) have been widely investigated as a passive thermal energy storage strategy for improving the energy performance of residential walls. However, their economic and environmental implications are less consistently addressed, limiting the integrated assessment of PCM design alternatives. This study investigates passive PCM applications in residential walls through an energy, economic, and environmental (3E) perspective and develops an evidence-informed decision framework for their design and assessment. A PRISMA-guided literature search covering 2015–2025 was conducted using Web of Science and Scopus, resulting in 55 eligible studies. All included studies assessed energy performance, whereas 31 focused exclusively on the energy dimension and only 10 addressed all three 3E dimensions. The findings indicate that PCM performance depends strongly on climate, phase-change temperature, thickness, position within the wall, and building characteristics. Economic outcomes are additionally influenced by PCM cost, local energy prices, and assessment boundaries, while environmental evaluations remain largely focused on operational carbon reduction, with comprehensive life-cycle assessments still limited. Based on the recurring patterns identified across the included studies and the detailed comparison of the 10 studies addressing all three dimensions, an evidence-informed decision framework was developed. The framework links application context and PCM design parameters with sequential energy screening, parallel economic and environmental assessment, and integrated 3E decision-making. The findings also underline the need for standardized indicators, long-term field validation, and multi-criteria decision-support approaches capable of comparing context-specific PCM alternatives across the three performance dimensions.