Multi-criteria assessment of bio-based construction on circularity, environmental impact and feasibility

Over the past decade, the construction industry has increasingly prioritized climate neutrality. In line with this, the EU Green Deal and its ‘Fit-for-55’ legislative package aim to reduce total emissions by 55% by 2030. A major challenge in achieving this goal is addressing the embodied carbon of building materials, which arises from production, transportation, and end-of-life stages. Reaching such targets requires a fundamental shift from the current linear construction model toward a circular and low-carbon approach. This study aims to explore the potential of bio-based building materials as feasible low-carbon alternatives and evaluates their circularity, environmental impact and feasibility by using established assessment frameworks. The research is focused on hemp-based building materials that are applicable in Turkish context. First, circular strategies including the 9Rs (refuse, reduce, reuse, etc.) and adaptation of existing tools such as Circular Built, together with emerging bio-based construction materials are reviewed. Then, a multi-criteria evaluation framework is developed to assess bio-based materials and applied on hemp-based materials. The results include a comparison between conventional and bio-based materials at component and building-level by utilizing a representation office building in Türkiye. In the end, the findings display 50% environmental impact reduction for the façade materials.