Toward Scalable Applications of Biomass Aerogels for Building Thermal Insulation

Biomass aerogels are emerging as lightweight porous materials for building envelope insulation. Reported thermal conductivities span approximately 13 to 170 mW m^-1 K^-1 and densities 8-260 kg m^-3 across diverse feedstocks, pore architectures, and hybrid formulations. Translation into building products remains constrained by structural instability, moisture-induced property loss, formulation-dependent fire behavior, interfacial degradation, energy-intensive processing, and limited product-level validation. We introduce an application-driven structure-failure-qualification framework linking feedstock compositions and product formats to building-specific performance requirements, pore structure designs, dominant service-induced failure modes, and validation requirements. We compare major biomass and hybrid material classes, product formats, and pore architectures according to their performance trade-offs, service vulnerability, and maturity of evidence. Multiscale pore engineering and bioinspired architectures can reconcile thermal insulation with mechanical integrity and environmental stability, but favorable specimen-scale properties do not necessarily establish deployment readiness. By connecting structure-property relationships with service condition reliability and standardised benchmarks, we elucidate the requirements for real-world translation. Future progress will require scalable hierarchical design, long-term durability validation, and harmonised sustainability assessment to support integration into next-generation low-carbon buildings.