Double-glazed units with a low-E coating cut solar heat gain and cooling loads far more than single glazing. Compare SHGC, U-value and visible light transmission together instead of judging a glass by one number.

In India, buildings taller than 15 metres need non-combustible cladding under NBC 2016. Standard polyethylene-core ACP does not qualify, so specify A2 or A1 rated fire-retardant core panels and ask for test certificates.