Double or triple glazing?

sliding sash windowDouble glazed windows consist of two panes of glass fitted between a window frame. Small gaps are present between each pane which are filled with air or an insulating gas, such as argon. Instead of using two panes of glass, triple glazing uses three. This makes the windows heavier and affects how they perform. Both types offer considerable benefits to homeowners, however if you’re looking for new windows and are unsure whether double or triple glazing is right for your home, we’ve created this short comparison guide. We offer a range of window styles, including upvc windows and casement windows that can be fitted with either type, so take a read to see which suits your home’s needs best.


A material’s effectiveness at insulating is measured in U-values, the measurement for which is W/m2k. And the lower the U-value, the better the material is at insulating. Better insulation means more heat is retained in your home, less cold spots near windows and higher potential to save on energy costs. When comparing the two, modern double glazed windows regularly attain U-values of 1.1 W/m2k, although triple glazing can achieve minuscule levels of just 0.8 W/m2k. So in terms of insulation, triple glazing is the clear winner.


As additional materials are used for triple glazing, the initial installation cost will be higher. However, because more heat is retained than with double glazed windows, they save you more each year on energy costs. Unless you plan on replacing your windows every 10 years or so, triple glazing is likely to save you more in the long run. Therefore, whether double or triple glazing is right for you may depend on the long-term aims for your home.


As an extra pane of glass is in use, the glass section of a triple glazed window is more reinforced than on double glazed windows. However, double glazed windows are extremely difficult to break anyway, and they’re fitted with the latest security hardware. Therefore, double glazing should provide more than enough security and compliment your entrance door’s security features.

Reducing external noise

The extra pane of glass on triple glazing means they allow in slightly less external noise. This ensures for a quieter home environment, which is especially useful is you live in a noisy area, such as near a main road or airport.

Carbon footprint

White uPVC casement georgian window As more energy and materials are required to manufacture triple glazed windows, the amount of carbon emitted into the environment is higher. So in terms of being greener for the environment, double glazing just about comes out on top.

Light intake

With the extra pane of glass, the amount of light making its way through the window is slightly reduced. Whilst most will find the difference between the two hard to detect, north-facing properties, where levels of light are notoriously low, are likely to benefit more from an increased intake of light.

Oakley Green – highly renowned installers of double and triple glazed windows

Oakley installs double or triple glazing constructed from uPVC, aluminium and timber. If you’d like to learn more about either, or you’re considering new windows for your home, give us a call on 01189 401 975 today. Alternatively, you can contact us via online message.