For new and replacement glazing within listed properties we are able to offer slim double glazed units. These are often called Heritage or slimlite units. They are normally 12mm thick with a glass edge to sight line of only 7mm. A sight line of 5.5mm is also available. Using a Krypton / Zenon gas mix even these slim units are still able to meet building regulations for insulation. These units can also be used to upgrade from single glaze to double glazing due to their overall thickness making them suitable for glazing in shallow windows.