Towards trustworthy LLM-assisted EPD comparability assessment for circular construction materials

Environmental Product Declarations (EPDs) are increasingly used to support construction material selection, but their comparability depends on how system boundaries and allocation rules are interpreted. Although large language models (LLMs) are increasingly explored for sustainability assessment, limited attention has been given to how methodological ambiguity affects LLM reasoning reliability and comparability judgement. This study investigates how LLMs interpret A1–A3 carbon emissions in EPDs for virgin and re…