Networks in complex interorganizational engineering project teams are shaped by individuals’ actions to perform specific project functions. These networks are dynamic; they change based on project needs, and each network structure influences the next. Particularly, this study examines how temporary knowledge-transfer networks in architectural, engineering, and construction (AEC) project teams emerge and evolve during project delivery, adopting different structures that are interdependent. We longitudinally analyzed the knowledge-transfer networks of an AEC project team with 79 to 102 members via statistical and qualitative analyses. Results showed that a core-periphery structure originally emerged in the project team network to support team coordination. Later, triangles among core and peripheral members emerged without disassembling the core-periphery structure and generating cohesive subgroups for deep knowledge transfers among team members. The findings shed light on the dynamic nature of knowledge-transfer networks in complex interorganizational project teams. Via informed network interventions, project managers can support knowledge-transfer structures that help improve team and project performance.