Optimizing structural and environmental performance in mass timber hybrid high-rise buildings through parametric design

Material selection plays a critical role in sustainable building design, requiring a balance between structural performance and environmental impact. Traditional Building Information Modeling (BIM) workflows often treat structural and environmental analyses separately, limiting efficiency in evaluating multiple design options. This study introduces the Structural-Carbon Integrated Design (SCID) framework, a novel BIM-based approach that integrates structural stability and embodied carbon assessments within a unified parametric workflow. The SCID framework was applied to 1,125 structural scenarios of the UBC Brock Commons Tallwood House an 18-storey mass timber-concrete hybrid high-rise by varying material combinations and element sizes for columns, flat slabs, and core walls. Results show that the benchmark hybrid configuration (Case I), which uses concrete for the core and timber for slabs and columns, achieved a 52% reduction in embodied carbon compared to a concrete-only structure (Case A), while incurring only a 40% increase in structural impact, remaining within acceptable performance limits. Fully timber structures achieved up to a 100% reduction in environmental impact, but suffered structural performance losses as high as 86%, rendering them impractical for high-rise applications. In contrast, concrete-only systems offered the highest structural reliability but the poorest environmental performance. SCID enables rapid, data-driven trade-off analysis and supports early-stage decision-making for low-carbon, high-performance building design. This case study demonstrates the potential of SCID to inform optimal hybrid strategies and enhance sustainability in tall building construction. • A BIM-based SCID framework was developed to integrate structural and environmental analysis. • 1,125 design scenarios were simulated for an 18-storey hybrid high-rise building. • Full timber systems were found structurally inadequate despite excellent environmental performance. • The hybrid design achieved 52% lower embodied carbon with only 40% structural performance penalty. • 249 optimized hybrid scenarios outperformed the original, proving the value of selective material use.