Abstract

The building sector is crucial in tackling the climate crisis by reducing raw material extraction and CO2 emissions. While operational emissions are significant, embedded emissions must also be considered. Optimizing structures can lead to considerable reductions, but constructability is essential for broader applications. This study proposes a novel computational framework that integrates multi-objective layout optimization and postoptimization rationalization to design efficient and buildable 2D truss structures. Using parametric modeling and evolutionary algorithms, the method explores thousands of design alternatives, optimizing for structural mass, average member utilization, and displacements under multiple load cases. The workflow includes a rationalization phase that evaluates varying levels of cross-sectional standardization to balance structural performance with constructability. The process was applied to three case studies, showing material savings and CO2 reductions of over 50%. Even though increasing the standardization of structural cross-sections for truss members increases mass and CO2 emissions, there are balanced solutions that can achieve an adequate reduction while maintaining ease of construction and compliance with displacement requirements. This approach supports informed early-stage decision-making, enabling designers to identify optimal trade-offs between environmental performance and construction feasibility.