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Double glazing versus Triple glazing windows and doors – The Facts.
When considering replacing old single-paned windows and doors with new double or triple glazed units, homeowners often face a dilemma about which glazing type to choose. Along with frame type, gas fills and spacers, energy use and warranties, there is a lot to consider.
How should you guide your clients to choose the right glazing system, and how do the benefits of each one stack up?
In this blog, we will specifically look at the facts around both double and triple-glazing, so that homeowners are able to make an informed decision on the glazing system that is right for them.
Single glazing
Although single-glazed windows may still be found in old properties and those in need of renovation, single glazing is no longer permitted under new-build construction laws. The act, brought in during 2002 states that new windows must conform to standard energy efficiency ratings. Windows and doors are given a ‘U-factor’, also called a ‘U-value’, which is ‘the rate at which a window, door or skylight transmits non-solar heat flow’.*
Single glazing scores extremely poorly in this area. The lower the U-factor rating, the more energy-efficient the glazing system is.
How is double or triple glazing more energy efficient?
Double-glazed and tripe-glazed windows have lower U-factor ratings due to the two or three panes of glass that are separated by an air gap or gas called ‘argon’. This gap, which is roughly 16mm in thickness, is completely sealed and helps to considerably reduce heat loss in a room, whilst also increasing sound insulation and therefore blocking out external noise.
Energy efficient glazing also reduces the build-up of condensation which can have long-term effects on the home and health of its occupants. With both double and triple-glazed windows, condensation is reduced as it cannot form between the panes of glass due to a component called ‘desiccant’ being used, which absorbs excess moisture.
Glazing systems are manufactured in different sizes, styles, materials and with various types of frames. Types of double-glazed and tripe-glazed windows include tilt & turn, which are often chosen for upper floor windows due to their security benefits, vertical sliding windows, sliding sash, flush sash and casement windows.
There is also the material of the frame for the homeowner to consider. uPVC is a popular choice due to its easy maintenance and the variety of colours available, but other options include hardwood and softwood, aluminium, and composite.
What are the major differences between double and triple glazing?
Unsurprisingly the major difference between double and triple-glazed windows is that the latter contains three individual panes of glass instead of two. Naturally, because there are 3 panes of glass and 2 ‘pockets’ of air between them, rather than 1, triple glazing offers additional heat insulation benefits over double-glazing and allows more efficient trapping of heat inside the property.
This results in reduced energy costs in addition to improved comfort, as temperatures will remain consistent across all rooms regardless of external weather conditions. This is an important consideration for homeowners with the current energy cost crisis.
Given the extra layer of insulation provided by triple glazing, there will be greater noise reduction compared to double glazing due to sound waves being trapped within the three panes instead of two.
Whilst both double and triple-glazed windows have considerably greater insulation benefits than single glazing, it does also mean that the heat of the sun is kept out, and therefore a house will not see the benefit of the natural warmth of the sun. In a country like the UK, which doesn’t typically see extremely hot weather conditions, this is less of an issue.
It’s also important to note that triple-glazed windows add an increase in security. Naturally, the extra pane of glass increases strength and will be much tougher to break through.
Triple-glazed windows do tend to be more costly than their double-glazed counterparts due to increased material costs, and so it’s important to weigh up the cost saving benefits of added insulation versus the financial outlay of the windows.
This increase in material means that environmental impact is also a consideration for both double and triple-glazed windows. Whilst undoubtedly, triple-glazing will be more energy efficient and reduce the homeowners carbon footprint, it will use more material in the manufacturing process, and it therefore comes with its own environmental cost.
In summary, it’s important for homeowners to carefully consider all these elements when choosing between double and triple-glazing. The decision will depend largely on individual preferences and circumstances, given that both offer distinct advantages.
At Edge Building Products we supply an extensive range of uPVC windows, bi-fold and patio doors, including all major styles, designs and finishing options. In addition, we also offer the only uPVC window specifically designed for triple glazing. A unique ‘flatter’ glazing bead accommodates a thicker glazed unit which can achieve U-values as low as 0.9 wm2k. We also offer a range of handle, hinge, and ventilation options.
Our PVC Window and Door Brochure is a great source of information if you are looking for more information on glazing options, you can read this online here.
For more information on our uPVC windows or any of the glazing system accessories we sell, please do contact us at [email protected] or telephone 0345 021 333.
With trade counters in Chichester, Horsham and Croydon, we have the broadest range of low maintenance building and glazing products in the market, and we are available to answer any questions in person or via email or telephone.
*Department for Energy