Infrastructure systems have long been designed and optimized around physical performance metrics—energy efficiency, structural integrity, operational uptime. Yet these systems profoundly shape the social fabric of the communities they serve, influencing outcomes like resilience to stressors, public health, and everyday well-being. At the same time, the people who inhabit and use these systems are not passive recipients of their services. Their preferences, routines, and social dynamics introduce both valuable structure and deep uncertainty into how infrastructure actually operates. Understanding this bidirectional relationship—how infrastructure shapes people and how people shape infrastructure—demands new models, methods, and interdisciplinary collaboration.

SocialSys'26 responds to this challenge by convening researchers across engineering, computer science, architecture, urban planning, cognitive science, computational social science, and behavioral modeling. The workshop builds on its previous iterations, as well as a call to action delivered in the 2024 BuildSys keynote by Professor Mario Bergés, who highlighted the community's urgent need to better capture and model human dynamics within infrastructure systems.

Whether the goal is human-centered—designing systems that deliver measurable social value—or system-centric—improving efficiency by accurately accounting for occupant behavior—SocialSys'26 offers a venue for the research community working to bridge that divide.