The rise of nanothermochromic materials for energy‑efficient glazing, recognizes windows as the major challenge for building energy losses and HVAC (Heating, Ventilation and Air Conditioning) demand as the sector that consumes more than 40% of total energy. The purpose of this paper is to provide a systematic review following the PRISMA 2020 guided search on Scopus (2015-2025) to identify the most recent advances and remaining opportunities in thermochromic materials modified by nanotechnology. Vanadium dioxide (VO2) has been stablished as an interesting material: across nanoparticles, patterned films, hybrid composites and nanoscale engineering that consistently improves visible transmittance (𝑇 𝑙𝑢𝑚), solar modulation (𝛥𝑇 𝑠𝑜𝑙 ) and tunes the transition temperature (𝑇𝑐) toward room temperature while strengthening durability and manufacturability. Wet‑chemistry and physical routes yield size and phase‑controlled VO2(M) compatible with scalable processing (inkjet, blade coating, sol-gel, hydrothermal synthesis, sputtering, atomic layer deposition). Elemental co‑doping lowers the 𝑇𝑐 with manageable optical characteristics; multifunctional stacks integrate electro‑, photo‑ and mechano‑activation to accelerate switching and sharpen spectral selectivity; polymer matrices and hydrogels provide flexible, low‑cost routes to enhance 𝛥𝑇 𝑠𝑜𝑙 , and core-shell VO2 architectures extend environmental stability. Nanothermochromic VO₂ have achieved advances such as high transmittance, strong solar modulation and lower transition temperatures through co‑doping, size control and scalable, durable designs, moving smart windows toward potential energy‑efficient application.
Alarcón et al. (Wed,) studied this question.