Impact of Seismic Design Requirements on the Environmental Performance of Reinforced Concrete Buildings: A BIM-Integrated Comparative LCA

Seismic codes in high-risk earthquake zones magnify the embodied environmental impact of buildings by increasing structural mass. While the existing literature evaluates this burden holistically, this study isolates the environmental penalty of seismic design at the component level using building information modeling (BIM). Within this scope, an eight-story reinforced concrete residential building was modeled at LOD 300 and comparatively analyzed under TBDY-2018 (seismic) and a strictly theoretical TS-500 (gravity-only) baseline scenario. This gravity-only model acts solely as a mathematical isolation tool rather than a buildable design option. Using the CML 2001 methodology and Türkiye-specific environmental product declarations (EPDs), calculations covered the production (A1–A3), end-of-life (C1–C4), and recovery (Module D) stages of the building. Findings reveal that seismic mass increases create a nonlinear, asymmetric effect on environmental indicators. Increased concrete volume dictates the global warming potential (GWP), whereas steel reinforcement—driven by ductility demands—elevates the photochemical ozone creation potential (POCP) and acidification potential (AP) much more aggressively than concrete. Conversely, while seismic reinforcement provides a negative emission credit during the recovery stage (Module D), quantitative analysis reveals that this circular benefit is marginally small (offsetting approximately 2% of the steel-related GWP), proving mathematically insufficient to neutralize the massive upfront ecological debt. Consequently, the additional environmental penalty necessitated by seismic safety must be managed through early-stage BIM optimization and alternative mitigation strategies, such as seismic isolation.