Coconut Coir Fiber Composites for Sustainable Architecture: A Comprehensive Review of Properties, Processing, and Applications

The growing need for sustainable materials in architecture has sparked significant interest in natural-fiber-based composites. Among these, coconut coir, a by-product of the coconut industry, has emerged as a promising raw material owing to its abundance, renewability, and excellent mechanical properties. The promise of coir-based composites in architecture is highlighted in this review, which also looks at their problems, advantages for the environment, manufacturing processes, and mechanical, thermal, and acoustic performances. The fibrous shape of the coir provides efficient thermal and acoustic insulation, while its high lignin concentration guarantees stiffness, biological resistance, and dimensional stability. Fiber-matrix adhesion and durability have improved owing to advancements in treatment and environmentally friendly binders, opening up the use of cement, polymers, and hybrid composites. In terms of the environment, coir composites promote a biophilic design, reduce embodied carbon, and decrease landfill waste. Moisture sensitivity, inconsistent fiber quality, and production scaling are obstacles; however, advancements in hybridization, grading, and nanotechnology hold promise. This review provides comprehensive, architecture-focused review that integrates material science, fabrication techniques, and real-world architectural applications of coir-based composites. Coir-based composites have the potential to be long-lasting, sustainable substitutes for conventional materials in climate-resilient architectural design if they are further investigated and included in green certification programs and the circular economy.