Technical barriers to circular economy implementation in the built environment: A problem-based multi-level review

• Technical barriers in the built environment are systemic and affect multiple levels • A multi-level problem-based approach is essential for effective CE implementation • Key barriers to knowledge and skills, processes and infrastructures are often neglected • Shorter service-life building layers, such as the space plan, are less investigated • CE focus remains on reuse and recycling rather than broader circular strategies The circular economy (CE) offers transformative potential for sustainability in the built environment. However, its implementation remains hindered by numerous barriers, including technical challenges. Although analysis of barriers in multiple impact areas is widely available, a comprehensive understanding of technical challenges has not yet been achieved. Moreover, barriers are commonly approached focusing on the urban, building, or material level without an analysis across built environment levels, even though implementing the CE implies a multi-level approach. This study carried out a systematic literature review applying a multi-level problem-based approach. It identified, classified, and analysed the key technical obstacles affecting CE implementation across the urban, building, and material levels which emerged from the literature. The research adopted an analytical framework across the levels, examining which technical barriers appear, where they occur in the building layers , when they occur along the lifecycle stages , who is involved as a stakeholder , and how the technical barriers influence the application of circular strategies . The results revealed that research on CE in the built environment has focused mainly on visible market or application-related issues, while placing less emphasis on foundational barriers to knowledge, skills, processes, and infrastructure. Because of these underlying gaps, the ability to develop, select, or apply technical solutions is constrained at every level of the built environment. By revealing inter-level interrelations and highlighting overlooked layers and strategies, this study provides a comprehensive understanding of current research on technical barriers affecting CE implementation in the built environment to inform future studies and direct target measures.