Secondary glazing works via a similar principle to double glazing, except instead of both panes being part of the same window, secondary panes are attached to the existing single-paned window from the inside.  Because there’s no seal, there’s no pressure difference between the inside and outside of the window.  What’s more, secondary glazing doesn’t require an entire window be replaced – it’ll simply slot behind the existing one.

While not as effective as double glazing, secondary glazing can be installed with minimum fuss to the rear of an existing single-glazed window, and will yield considerable improvements in thermal efficiency.  They’re therefore a popular solution for owners of period property.

Secondary glazing also tends to be considerably cheaper than double glazing, so is ideal for homeowners with a limited budget.

Energy is expensive. That’s why it’s crucial homeowners take steps to ensure they get the most from every penny spent.  If you’re looking to keep your home warm and energy efficient, particularly during winter, then you’ll want to concentrate your efforts on the areas of your property most at risk.

Almost inevitably, windows form a weakness in a building’s outer shell.  Through them, heat can easily escape into the world outside, which in turn cools the property and necessitates further energy expenditure.

We can combat this problem in part with double glazing, or to a lesser extent, secondary glazing.

What is double glazing?

Double glazed windows are formed of two panes of glass, separated by a thin cavity.  When the technology was first developed, this space was filled with ordinary air.  Then it was realised that dehydrating the interior of the window would prevent condensation from forming during cold spells, and improve performance.  At that point manufacturers began to drain the air entirely from their windows, filling the space instead with a vacuum.

Today double glazing is most often filled with an inert gas, like argon, krypton or xenon.  Of these, argon is the least effective – but it’s also the least expensive – which means it’s a popular choice with many homeowners.

Secondary Glazing can be a DIY job; double glazing needs a professional!

As mentioned above the double-glazing units have to be made to order for your home, however once they have been built (when I had these installed it took about 6 weeks for them to be made), the installer can install about 3 windows per day. So the process is relatively quick, however this is certainly not a DIY project.

Installing secondary glazing can be done as a DIY job, however there are also companies out there that can come and install the secondary glazing for you. In comparison, since you don’t need to remove any existing window units to install secondary glazing, the process of installation is far simpler.

Secondary glazing provides a better level of acoustic insulation

Both types of windows are also great at cutting out noise pollution, however secondary glazing takes the winners medal here. Unlike the double-glazing sealed units, the two different pieces of glass in secondary glazing act as independent barriers to the transmission of noise. The greater the cavity between the two panes, the better the dampening effect – so double-glazing which has panes relatively close together is less good at cutting out noise.