There are several types of low energy glazing, such as ‘double / triple glazing', and ‘secondary glazing'. Plus now you can use special ‘Low-emissivity' glass that saves even more energy. These terms are explained below
Double / Triple Glazing
Double / triple glazing is where a window has two or three special panes of glass, fitted in a frame which seals that glass around its edges, and traps air or an inert gas in between the glass panes as a layer of insulation.
Secondary Glazing
Secondary glazing is where a second layer of glass is fitted inside an existing window frame, but does not have an airtight seal and so is not as effective as double or triple glazing. However, it does significantly reduce the heat lost through a window, and reduces draughts and noise. Plus it can also be cheaper than fitting double or triple glazing.
Low Emissivity (Low E) Glazing
Low-emissivity glass (Low E) looks just like normal glass, being clear to see through. However it has a very thin coating of metal or metal oxide on the outer surface of the pane which blocks heat from leaving the room. At the same time it allows heat from the sun to enter the room. The coating is almost invisible, so the windows will seem just like normal.
