Often considered an inferior option to full double glazing, nevertheless many people have no alternative other than to have secondary glazing installed in an effort to reduce their home's heat loss. While installing modern, energy-efficient double glazing is easily the preferred option for many people.
Among the most common reasons for being unable to go down this route is that you live in a conservation area or a listed building, where such changes are expressly forbidden, or that your windows are of non-uniform shapes and/or sizes.
In many such cases, your only option might be to have secondary glazing installed. However, this means you do not get the main benefit of having full double glazing, which is that the air trapped between the two panes of glass or the inert gas which is specially pumped into the space acts as an extra insulating layer.
Instead, with secondary double glazing, as you can access the gap between the panes of glass, this allows air to enter, so in many cases, it does not solve any condensation problems which you may have had with just single glazing.
However, as the air trapped between the layers of glass can escape, this means that the condensation can be cleared, whereas if you suffer this problem with double-glazed windows, and it is especially common with older, less-well manufactured windows, it creates 'fogging', which is even harder to eliminate. It also means that, if you need to open your inner windows regularly, for instance, to clean them, you might cancel out the benefit of having the secondary windows installed in the first place.
Where secondary glazing certainly can help, however, is in improving a building's sound insulation. You will notice a considerable improvement in the noise levels in a room with the addition of a second layer of glass. The best all-round option for secondary glazing is a single, hinged unit. This is because you will retain all of your view out of your window, and you will achieve improvements in both sound reduction and energy saving.
Of course, another advantage of choosing secondary glazing is that you can just have it fitted to the windows which will benefit the most from the extra noise or heat insulation, thus saving time on the installation itself and, of course, money. So you might just choose to have the extra glazing installed in your living room and certain bedrooms.
