How to Fit Your Own Glazing

double glazed window looking out onto orchard
(Image credit: getty images)

In its basic form, double glazing is two pieces of glass hermetically sealed with a cavity in between. The main benefits are improved heat and sound insulation. Cavity sizes vary, but you’re most likely to see a gap of between 12mm to 20mm sandwiched between two sheets of glass either 4mm or 6mm thick. If you have a big enough rebate in your window frame, larger gaps between offer greater insulation, but go wider than 300mm and convection currents increase heat loss.

Over the years, there have been some significant leaps in technology for both the glass used in double glazed units and the gas that goes between it. And as units occasionally fail, it’s a good chance to upgrade your window’s performance. Even better, you can do it on a DIY basis.