Toward climate-resilient and fire-safe buildings: Multifunctional surface materials integrating radiative cooling and flame retardancy

Amid the escalating urban heat island effects and increasing fire hazards driven by climate change and rapid urbanization, buildings face two parallel challenges: excessive heat accumulation and heightened fire vulnerability. Multifunctional surface materials that integrate passive radiative cooling (PRC) and flame retardant (FR) have emerged as promising solutions for enhancing both energy efficiency and fire safety. By synergistically combining PRC and FR functionalities, these materials can reflect solar radiation and emit heat to reduce surface temperatures, while simultaneously inhibiting ignition, slowing flame spread, and suppressing toxic smoke via gas-phase and condensed-phase mechanisms. This review presents a comprehensive overview of their working principles, performance evaluation methods, and material classifications of such materials, focusing on four main systems: organic polymer-based materials, polymer–inorganic composites, bio-based materials, and other material systems. Particular emphasis is placed on the relationship among materials, structure, and properties, strategies for integrating multifunctionality, and the influence of environmental conditions on long-term performance. Key challenges related to climate adaptability, outdoor durability, and filler dispersion are discussed to guide future research. These materials offer a promising pathway toward energy-efficient, fire-safe, and climate-resilient buildings.