AbstractArchitecture, engineering, and construction (AEC) project teams have a segmented organizational structure with subgroups, for example, designer, contractor, and owner. AEC projects are challenging to collaborate because they require those in different subgroups to address uniquely defined technical and functional contexts. The AEC industry often seeks integrated collaboration through organizational integration because the literature assumes that organizational structure determines collaboration structure. This study uses a network perspective to identify the inconsistency between the organization and collaboration networks through the data of email records from a $20 million AEC project with a typical fragmented organization. The analytical focus is on two network configurations: (1) a community structure through which subgroups are defined to attend to specific aspects of the project and then coordinated through ties between members of different teams; and (2) a core-periphery structure in which a relatively small number of members interact frequently in the core and then coordinate as each member of the core interacts with specific members of the periphery. Results provide evidence of integrated collaboration in fragmented project organization, indicating organizational integration is not a must to achieve integrative collaboration. The findings suggest implications to facilitate integrative collaboration: (1) efforts should focus on collaboration behaviors, (2) subgroups should adopt a dual-lead pattern, (3) subgroups should encourage non-high-profile members to function as cores, and (4) subgroups should ensure information sharing and prevent information overload.