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Triple Glazing Costs - How Much Can You Save?

Author: Samuel Beckingham
Updated: Nov 08, 2023
8 minutes read
  • What triple glazed windows cost compared to other types
  • Payback period for triple and double glazing
  • Pros and cons of triple glazing

When it comes to making your home more energy efficient, triple glazing can be beneficial for you. As opposed to single glazing, triple glazed windows are made from three panes of glass with two insulating layers between them. It is a step up from double glazing but provides even more protection for your home, both in terms of heat retention and security.

This article will detail how triple glazed windows work, along with the costs involved. Depending on which material you choose for your frames, the price will be greatly affected. The article will then look at how much you could save when triple glazing windows and how this will affect the payback period.

Looking for new windows? Why not fill in our quote comparison tool to find out how much you’d pay for triple glazed windows? It only takes a minute.

A cross section of a white uPVC triple glazed window standing on floor plans

What Is Triple Glazing?

A triple glazed window is an extra sandwich of insulation between a third pane of glass. Where double glazing has one insulating layer filled with an inert gas, triple glazing has two. This decreases the amount of hot or cold air transmitted through the window, keeping your home even warmer.

Window Glazing Vector

Compared to double glazing, triple glazed windows can be up to 60% more efficient than older windows, or 24% more efficient than new units. It’s all thanks to the gas filled chambers. Usually packed with a gas that’s heavier than air, such as argon, any thermal transfer is slowed. This also works with noise too, reducing unwanted intrusive sounds from coming through.

One of the downsides is that triple glazing is much heavier and needs more support for the glass. This can prove problematic for homes that aren’t as structurally sound. If your home can’t support extra weight, triple glazed windows might not be for you.

Triple Glazing Costs

Triple glazing is more expensive than double glazing, purely because of the extra materials involved. Checkatrade estimates the average cost of triple glazing to be around £1,200 per square metre. With this in mind, installing 4 triple glazed windows in a flat will cost around £4,800. On the other hand, 15 windows in a detached home will be about £18,000.

You can see typical triple glazing costs by property type in the table below.

These costs only factor in the average price per square metre, not the various sizes, styles or materials that you might choose for your windows. This means that the prices you pay could be cheaper or more expensive than the prices listed above.

Looking for a more accurate figure? Fill in your details for a tailored quote for triple glazing from a local supplier by clicking on the button below.

Cost of Triple Glazing vs Double Glazing

While it’s useful to look at triple glazed window costs in isolation, it’s useful to see how they compare to double glazing costs. If you’re on a budget or are wondering how much you could save with a cheaper option, you might be interested to see the differences in prices by material.

Living Room Isometric

White uPVC windows are the cheapest option, and these can be around £900 for double glazing. The same material but triple glazed will be considerably more, at £1,450. Likewise, timber windows can cost £1,500 to double glaze but £2,000 to triple glaze. When considering the price, it’s important to see how the materials affect what you pay.

You can see how triple glazing prices vary by type of window material and size in the table below. Coloured or textured uPVC frames cost 10–20% more than white frames.

It’s worth noting that the more you pay for windows, the longer the payback period will become. Although you’ll be saving on your energy bills, the amount you save a year will only be small in comparison to what you paid for the windows. The more energy efficient your home is before you install triple glazing, the longer it will take for the windows to pay for themselves.

How much would it cost to double glaze a 3 bedroom house?

How Do Double and Triple Glazed Windows Compare?

Although the costs are higher for triple glazed windows, the comparison to double glazing can point out the benefits that you’ll be paying for. We’ll compare different glazing types in the following ways:

  • Thermal efficiency

  • Soundproofing

  • Home security

  • Light transmission

Thermal Efficiency

Heat transfer in glazing is measured by U-values. It’s a calculation based on the rate of energy transfer through one square metre. The calculation is displayed as watts per square metre per Kelvin. As an example, a window with a U-value of 1.4 means that 1.4 watts of heat are transferred per metre square for every temperature difference by 1°C, both inside and outside.

Essentially, the higher the U-value, the more heat is transferred and lost. A good U-value should meet Building Regulations or, ideally, be even lower. Triple glazing tends to have low U-values, which keeps your home warm and comfortable. The most energy efficient windows have low U-values, and you can see typical measurements in the interactive graph below.

Triple glazing is at the head of the pack with a U-value of 0.7, while single glazing is far worse at 5.2. Between secondary and double glazing, there isn’t much difference, but double glazing performs better with a U-value of 2.6. On thermal efficiency alone, triple glazing is the clear winner.


When it comes to reducing the amount of noise transfer through windows, the barriers need to be improved by either increasing the gap between panes or using thicker glass. Simply adding another pane increases acoustic protection. Unfortunately, trickle vents do nothing for noise reduction, despite being a legal requirement.

Any extra gap in glazing should be at a different measurement in order to be more effective. This is because it changes the sound waves as they travel through the window. If your triple glazing is equally spaced, you may be no better off with sound reduction than by using double glazing.

You can see typical noise reduction levels in the interactive graph below.

If your triple glazing isn’t manufactured with soundproofing in mind, it can only offer 1dB more acoustic protection than single glazing. This is because the third layer can amplify sound through vibrations. With sufficient glazing and gaps, triple glazing can offer a 40dB reduction in outside noise levels.

The clear winner for soundproofing is secondary glazing, which can reduce noise levels by up to 54dB. With a bigger gap between each pane, noise is greatly reduced.

See how double and secondary glazing compare in our related article.

Home Security

The more panes there are in a window unit, the better protection you have. It makes it harder to break into, which increases the security of your home. Laminated layers of glass can increase home security even further by keeping the glass together if it’s broken. In terms of extra security, triple glazing is the clear winner.

Light Transmission

Though transparent, glass is actually green. The more panes you add, the darker it will become, which reduces the amount of natural sunlight the window will let in. Triple glazing has the unintended effect of making your home appear darker.

Unlike double glazing, which doesn’t suffer from this problem as much, triple glazed windows cost you a little light transmission. In this way, secondary or double glazing are superior to triple glazing.

Double vs Triple Glazing Vector

Payback Period for Triple Glazing Costs

The real question is how much you can save on energy bills with triple glazing and how long it will take to pay for the installation. For the sake of argument, a typical yearly heating bill is £1,326 a year. About half of this is used for heating (£663).

Double glazing saves you roughly 10% on your heating bills a year, giving you an extra £66. Providing this stays constant, the payback period for a £5,000 double glazing installation will be 76 years.

Triple glazing supposedly saves you an additional 15% on your energy bills, giving you an extra £165.75. Providing this stays constant, the payback period for a £7,275 triple glazing installation will only take 44 years.

You can see how these payback periods compare in the interactive graph below.

The more money you save with your new windows, the quicker the payback period will be. These figures are estimates that don’t take into account the full picture of a home’s heat loss.

Pros and Cons of Triple Glazed Windows

The main advantages to triple glazing are in their efficient properties. These reduce the amount of heat lost, keeping your heating bills down and reducing the chance of condensation appearing. As they can regulate their temperature a lot easier, there’s less chance of water droplets appearing on the surface, unlike with double glazing.

On the downside, triple glazing costs are the main disadvantage. Paired with the heavier material and the potential to not provide sufficient soundproofing if not installed correctly, these cons can put you off. Additionally, the UK climate isn’t considered cold enough to warrant the use of triple glazed windows, unlike other countries. While you do receive more efficient windows, the winters aren’t harsh enough to give you better energy savings.

The benefits do outweigh the drawbacks of triple glazing, so if you’d like to find out how much you’d pay for new windows, why not fill in your details and get a tailored quote from a local supplier? Click on the button below to get started.