Evaluation and comparison of LCA (Life Cycle Assessment) free software

Sammanfattning

This study evaluates and compares the embodied carbon of a structural steel bracket using three free Life Cycle Assessment (LCA) tools: openLCA, Embodied Carbon in Construction Calculator (EC3), and Sustainable Minds. A consistent functional unit of one structural steel bracket with a mass of 0.28445 kg was applied across all software tools to ensure controlled comparability. The assessment follows the ISO 14044 framework and applies a cradle-to-gate system boundary focusing on raw material extraction,material processing, and primary steel production. The environmental impact assessment focused primarily on Global Warming Potential (GWP), expressed in kg CO₂ equivalent. The results showed noticeable variation between the software tools, with Sustainable Minds producing the highest carbon footprint value, followed by openLCA, while EC3 generated the lowest result. openLCA and EC3 showed relatively strong agreement compared to Sustainable Minds. The observed differences were mainly attributed to variations in background databases, impact assessment methods, and modelling approaches. While openLCA and Sustainable Minds rely on process-based databases, EC3 uses manufacturer-specific Environmental Product Declarations (EPDs), resulting in different environmental impact outputs. The findings demonstrate that Life Cycle Assessment results are highly sensitive to software selection, database structure, and methodological assumptions. The study highlights the importance of transparency and careful interpretation when comparing environmental impact results across different LCA tools.