Abstract: Engineering project networks (EPNs), as digitally mediated units whose team members are scattered across differentorganizations/locations, have become the norm for construction project teams. In EPNs, virtuality captures various forms of boundariesamong team members and influences major dimensions of team functioning and outcomes. Despite this importance, investigating the roleof virtuality on the functional performance of EPNs has remained an unexplored area. Through a multidisciplinary review of literature, atheoretical model has been created to conceptualize the fabric of links between virtuality and effectiveness in EPNs. The theoretical basis ofthe model is the Big Five theory of team effectiveness. The model has been evaluated using empirical data collected from 285 completedquestionnaires, and analyzed through the use of partial least squares structural equation modeling (PLS-SEM) technique. Quantification ofassociations reveals that virtuality significantly affects effectiveness in teams by manipulating several mediators. However, the level of in-fluence of virtuality on these mediators, and eventually effectiveness, is much lower than previously assumed by current literature. This studygoes beyond existing studies, presenting the first quantified model of virtuality applicable to any type of EPN in the construction context.