Supply chain management (SCM) and building information modelling (BIM) are innovations that focus on integration. Recent literature suggests performance benefits from combining these innovations. Within supply chain (SC) partnerships, that use BIM - hereinafter called BIM-enabled SC partnerships - various formal and informal dimensions influence the inter-organizational relations. To understand such partnerships, a mixed method approach featuring case studies and social networks analysis (SNA) was deployed. SNA was an analytic approach to explore the complex relations within two Dutch BIM-enabled projects. The inter-organizational relations were asymmetrical and formal in Case A, emphasizing transactions, whereas in Case B, they were asymmetrical and informal, emphasizing relations. The transactional-oriented partnership had greater control over contractual issues, but their formal relations were not sufficient for diffusing BIM-related knowledge across the chain. Conversely, the relational-oriented partnership engaged the partners in BIM by informal means, e.g. dense communication and BIM-related peer-learning across all tiers. Symmetric and jointly fostered formal and informal relations contribute to SC integration. The study extends the knowledge base of SCM and BIM, by offering real-world data on their combination. Besides providing new insights into SNA deployment for BIM-related research, it also offers a novel constructivist and inter-organizational perspective on the old concept of SCM.