The invention concerns an insulating glazing wherein the gap between the substrates is filled with at least one rare gas such as argon, krypton or xenon, the inter-layer sheet (50) has a thermal conductivity less than 1 W/m.K, preferably less than 0.3 W/m.K, a low-emissive coating being deposited on at least part of one of the substrates, an anti-frost coating being deposited on part of at least the outer surface of one substrate, the glazing being free of heating element, the glazing having a thermal conductivity coefficient U less than 1.2 W/m.K with a gas filling of at least 85%, and having a light transmission of at least 67% and a light reflection less than 18%.