Some types of new glass have a special quality of heat insulation which classifies them as low-e glass (low emissivity glass) or K-glass. Replacing the glass with another low-e pane or unit would be a legal requirement so we are on hand to ensure this is taken care of so you dont have to. Alternatively you may desire extra insulation from your double glazing. We can cater for you by filling a standard double glazed unit with argon gas during the construction stage.