In cold regions, public buildings often suffer from suboptimal thermal performance due to cold air intrusion. This study explores the synergistic impact of multiple spatial parameters on winter thermal environments to discover the passive optimization potential in commercial complexes. Airflow analysis covers the entire connected space from the entrance to the large atrium, integrating the collective effects of all critical spatial parameters. Based on 4500 Computational Fluid Dynamics (CFD) simulation, the study establishes how these parameters influence wind resistance and thermal comfort. Key findings reveal that the “Atrium-plan Ratio,” “Transitional Space-width,” and “Atrium-height,” are most impactful on wind resistance, contributing over 53 % collectively. For thermal comfort, “Atrium-volume,” “Atrium-section Form,” and “Atrium-height,” are most significant, with a combined weight exceeding 57 %. As wind speed increases, the effect of single parameters gradually diminishes, highlighting the synergistic effect of spatial combinations. A case study demonstrates an 80.5 % improvement in thermal performance score following optimization, underscoring the potential for low-carbon, high-efficiency design in commercial complexes.