If your office has had the double glazing fitted for many years then you may have noticed that the odd pane or two is looking a bit steamy at times – this means the seal is broken and the pane needs replacing. However, many offices that had double glazing fitted in the eighties and early nineties will be much less energy efficient than modern units. A double glazed unit consists of two panes of gas separated by an air gap (now usually filled with a gas like argon).

This gap between the panes provides the layer of insulation that reduces heat loss and condensation. Double glazed units are generally available with gaps from 6mm to 20mm but early installations of double glazing had the 6mm narrow air gap and the closeness of the panes mean that heat can pass from the inner to outer pane. Nowadays the optimum gap is probably 16mm and the units should also be fitted with Low E Glass (Low Emissivity Glass). This type of glass has a very thin layer of a metallic coating on one side – the coating allows the heat from the sun to enter the building but reduces the heat loss from the inside by reflecting the heat back into the room.

Upgrading old double glazing is a real energy saving investment as well as a chance to upgrade the way the office looks as there are now many frame finishes and style of windows. It is worth checking with a double glazing specialist such as SEHBAC to see what such a transformation could cost bearing in mind not only will you get the benefit of saving money and adding value to your office premises, the office environment will also be significantly improved and in turn may lead to higher productivity!