Integrating Circular Economy in Retrofit: Global Practices in Sustainable Construction

The construction industry is among the most resource-intensive sectors globally, contributing approximately 39% of total carbon dioxide emissions. Retrofitting existing structures has emerged as a crucial pathway toward achieving sustainability goals. Integrating Circular Economy (CE) principles—such as material reuse, lifecycle assessment, and closed-loop design—into retrofit strategies can significantly enhance resource efficiency and environmental performance. Despite growing interest, the global application of CE in retrofitting remains inconsistent and underdeveloped across regions. This study presents a structured synthesis of global practices at the intersection of CE and sustainable retrofit strategies within construction engineering and project management. A systematic literature review was conducted using the PRISMA methodology across major academic databases, yielding 44 relevant studies and empirical case examples published between 2010 and 2024. Thematic coding was applied based on three dimensions: circularity potential, retrofit performance, and stakeholder engagement. Findings indicate that CE-informed retrofitting is gaining momentum, particularly through approaches such as modular construction, adaptive reuse, and material recovery. Enabling technologies like Building Information Modelling (BIM), digital twins, and lifecycle assessment tools, along with supportive governance frameworks, are identified as key enablers. However, challenges such as limited CE expertise, high upfront costs, inconsistent policy implementation, and inadequate secondary material databases continue to hinder widespread adoption. Regional comparisons reveal leadership in Europe and parts of Asia, while emerging innovations are observed in select Global South contexts. The study concludes that effective CE-based retrofitting requires the convergence of integrated project management, enabling technologies, and harmonized regulatory mechanisms. Future research should focus on developing standardized frameworks, quantifiable impact evaluation models, and comparative cross-regional analyses to accelerate global adoption.