The benefits of modular integrated construction (MiC) are extensively documented. Rapid and effective implementation of MiC will leverage significant gains in construction project performance. However, its widespread diffusion and uptake have been hindered. Although manifold empirical studies have identified the barriers to the adoption of MiC in different countries, holistic international review and integrated conceptual framework for the barriers are not well-established. This research analysed studies on the barriers conducted in 15 countries across five continents. Based on a meta-synthesis framework, the research identified 120 barriers to the adoption of MiC. The analysis revealed a co-existence of both perceived and real barriers, for which the authors argued that some existing studies may have engaged inexperienced participants during their surveys. An extended classification framework is proposed to group the 120 constraints into knowledge, attitudinal, financial, technical, aesthetic, industry, process, and policy clusters of barriers. The paper proposed an integrated conceptual framework mapping the interactions among the barriers. The framework revealed that the 5 most symbiotic clusters include industry, knowledge, process, financial and technical barriers which have at least 4 interactions with other groups. The paper further proposed strategies to address the identified groups of barriers. Thus, this research has established the ecosystem of the barriers, and how they hinder the wider diffusion of MiC. As such, it provides a holistic perspective of the barriers to the wider diffusion of MiC and initiated a debate towards developing integrated strategies to promote uptake of the technique. (C) 2019 Elsevier Ltd. All rights reserved.