Old building reconstruction initiatives are instrumental in achieving sustainable urban regeneration, yet they often grapple with substantial complexities concerning community involvement. A review of the existing literature presented a lack of studies examining how community engagement influences project complexity. This research aims to bridge this gap by investigating the interrelationship between community involvement, project complexity, and the impact of community information dissemination. A comprehensive set of measurement items was initially developed through a literature review and discussions with experienced practitioners to form the questionnaire survey. Subsequently, data collected from 168 respondents were subjected to analysis employing the Structural Equation Modeling method. The empirical findings provide compelling evidence of negative relationships between community information dissemination and community involvement with project complexity. Furthermore, the study highlights a positive relationship between community information dissemination and community involvement. This research underscores the pivotal roles of community engagement and information sharing in the quest for sustainable urban regeneration. It emphasizes the critical significance of transparent communication, community participation, and empowerment as indispensable components within OBR projects, all contributing to the broader achievement of sustainable urban regeneration.