The effect of thermochromic coatings of vanadium dioxide (VO2) on the fire performance of windows was experimentally tested. Prototypes were subjected to radiant heat and the radiation transmitted through the specimens was measured as a function of time. The results indicate that windows coated with VO2 can reduce radiative heat transfer from fires and thereby also reduce or prevent fire spread. The results clearly show that VO2coatings on BK7 substrates hinder approximately 30% of the transmission of radiation from fire sources when compared with the performance of uncoated windows. It is expected that VO2 will not be solely implemented for the purpose of increasing fire performance of windows, but it will rather provide a secondary positive effect if such windows are realized for energy‐saving purposes.