Fuzzy Synthetic Evaluation of the Role of Algae-Based Materials for Sustainable Construction in South Africa

Climate change is impacting ecosystems and infrastructure worldwide, prompting the construction industry to adopt sustainable practices to reduce its carbon footprint. Nature-based Solutions (NbS), such as algae-based materials, are emerging as beneficial alternatives to traditional construction materials. However, research on these innovations in South Africa is limited. This study presents findings from a preliminary assessment of algae-based materials in the country’s construction sector. A post-positivist stance was employed, using a quantitative research design with a questionnaire survey targeting built environment experts. Data analyses were performed using frequency counts, mean item scores, the Kruskal–Wallis H-test, and Fuzzy Synthetic Evaluation (FSE). The findings show low awareness and usage of algae-based materials, with bio-carbon cement as the only widely recognized option. However, the study identifies potential applications of algae in masonry, wall finishes, and concrete for structural elements. FSE indicates that respondents perceived algae-based materials as having significant environmental, social, and economic implications for sustainable construction. Based on responses from 63 built environment professionals from one South African province, this study provides context-specific insights into the potential integration of algae-based materials in the construction sector and identifies avenues for future research on practical applications, regulatory challenges, and the potential for scaling in other developing countries.