Challenges and Prospects of Building Thermal Insulation Coatings in the Low-Carbon Transition

Global building energy consumption accounts for approximately 35% of total energy use, with its full-life-cycle carbon emissions emerging as a critical factor in achieving carbon peaking and neutrality goals. In China, for instance, operational building carbon emissions exceed 50% of the national total, while thermal losses through building envelopes in extreme climate zones like Xinjiang contribute over 50% of total energy consumption, underscoring the pivotal role of thermal insulation coatings in energy conservation. This review systematically examines conventional thermal insulation coating systems—including barrier-, reflective-, and radiative-type technologies—based on their porous structural optimization, high-refractive-index filler composites, and atmospheric window spectral regulation mechanisms. It further introduces emerging functional coatings: phase-change types utilizing microencapsulation to address leakage constraints, bioinspired coatings mimicking biological thermal management through hierarchical micro-nano structures, eco-friendly variants employing bio-based materials to reduce environmental impact, and transparent coatings balancing optical transparency with thermal insulation via nanocomposite engineering. However, current systems face persistent challenges including multi-scale interfacial instability, process cost-effectiveness limitations, and insufficient cross-climate service performance databases. Future research must prioritize breakthroughs in dynamic thermal-responsive smart materials, high-throughput directional assembly processes, and innovative full-life-cycle carbon accounting methodologies. These advancements will promote the evolution of building energy efficiency toward adaptive regulation and ecological sustainability, offering systematic solutions to support global carbon neutrality objectives.