Integrated lifecycle cost analysis ( <scp>ILCCA</scp> ) framework for infrastructure systems

Abstract The transition towards net‐zero carbon infrastructures necessitates decision‐making frameworks that integrate economic performance with environmental externalities. Conventional Life Cycle Cost Analysis (LCCA) evaluates financial costs but does not account for carbon emissions, while Life Cycle Assessment (LCA) quantifies environmental impacts without enabling direct economic comparison. This study proposes an Integrated Life Cycle Cost Analysis (ILCCA) framework that combines Life Cycle Economic Cost (LCEC) and monetized Life Cycle Carbon Cost (LCCC) into a unified decision metric. The methodology adopts a cradle‐to‐grave system boundary (Modules A–D) consistent with ISO 15686‐5 and EN 15978, incorporating capital, maintenance, user, and end‐of‐life (EoL) stages. Carbon emissions across all life cycle stages are monetized using a time‐dependent carbon price and discounted to present value, enabling direct aggregation with economic costs. The framework is demonstrated through a comparative case study of two bridge alternatives: a concrete deck bridge, and a steel composite deck bridge. Results indicate that while the steel alternative exhibits higher recyclability benefits, the concrete bridge achieves a lower Integrated Life Cycle Cost (ILCC) due to reduced initial and maintenance costs. Sensitivity analysis shows that increasing carbon price narrows the cost gap between alternatives, highlighting the influence of carbon monetization on design decisions. The proposed ILCCA framework provides a practical decision‐support tool for climate‐aligned infrastructure planning, enabling transparent evaluation of cost–carbon trade‐offs and supporting sustainable procurement and policy formulation.