Repairing Double Glazed Windows Double-glazed Windows "blow" they let the gas that insulates them, argon, escapes, which causes them to reduce their energy efficiency. The good news is, blown double glazing is often repairable without having to replace the windows. The most typical sign of a damaged window seal is https://www.repairmywindowsanddoors.co.uk/carshalton-windowrepair/