Recent reports underscore the growing significance of embodied greenhouse gas emissions in the building industry, necessitating sustainable structural designs to combat climate change. However, the current building and structural design codes require satisfying Ultimate and Serviceability Limit States (ULS and SLS) without setting limitations on embodied emissions in the design process of structural members. Thus, this study proposes an Environmental Impact Limit State (EILS), specifying allowable and design emissions for structural components, to be used alongside ULS and SLS. The EILS combines nominal emission intensities from parametric analysis with fuzzy-logic-based uncertainty factors, enabling standardized consideration of environmental impacts in sizing structural elements. The EILS calibration is demonstrated for flat slab and shear wall systems following Canadian codes. The calibration involved an extensive parametric study (450, 975, and 2160 configurations for flat slabs, columns, and shear walls) to evaluate the impact of design and loading parameters. A detailed numerical example is presented to showcase the incorporation of EILS in the design process, achieving emission reduction on magnitude of 25 % compared to non-EILS design process.
