Triple Glazing: All your Questions Answered

So you’re thinking of getting triple glazing but aren’t sure if the extra pane of glass is the right investment for you? This guide answers all frequently asked questions so that you can make an informed decision.

They have many amazing benefits that suit the needs of those looking for energy efficiency, secure, warm and money savvy homes. Explore our comprehensive guide to see if they suit your needs.

What is the Difference between Double and Triple Glazing?


What is Double Glazing?

Double glazing has two layers of glass with spacer bars that are filled with gas. Energy efficient double glazing comes in a variety of different window frames that is usually formed of uPVC or traditional woods.

If your old double glazed windows aren’t providing you with the heat retention and saving on your energy bills that you expected, new windows may be next on your list.

What is Triple Glazing?

Firstly, it has three layers of glass instead of two. The extra pane can make a difference to your energy efficiency.  Between each pane of glass, there is a small gap which is filled with air or an insulating gas such as Argon. Argon gas has the same solubility as oxygen and is colourless as well as odourless.

It has been a popular choice in places such as Switzerland and Norway due to their cold climates. It has become increasingly popular in the UK because of its benefits.



  • Improves energy efficiency and energy rating.
  • Thermal efficiency- Reduced heat loss which reduces heating bill.
  • The Insulation holds the heat in your home, enabling you to stay cosy.
  • Increases home security due to its strength and extra layer of glass.
  • The thickness of the glass provides sound insulation and reduces external noise.
  • More rigid and durable than traditional windows.
  • Resistant to condensation
  • Eliminate cold spots
  • Low emissivity and energy saving.


  • The weight of three panes of glass can sometimes cause problems with weaker sash materials. Harder Upvc windows can handle them fine.
  • If the existing structure has little or no wall insulation, it may not make a huge difference.
  • Sometimes the casements may have width limitations that are restricted when opened.
  • The weight can also add labour costs to your installation budget.
  • It can cost 25-30% more than double glazing.

Triple Glazing Cost 

The more triple glazed windows you install, the cheaper each window will be and the more money you can save. It is more cost effective to change all your windows at the same time.

Triple Glazing cost can be affected by many things such as:

  • The material you want for the windows e.g. Timber or uPVC.
  • How many windows you need.
  • The size of your windows.
  • The style of your windows e.g. bay or triple bay window.
  • The widow specialist you use and the quality of their window provider.

The cost per square metre is around £400- £550. However, this price would be dependent on the above variants. Therefore, an average price cannot reflect the actual cost for your home.

Is Triple Glazing Worth it?

Installing triple glazed windows is the equivalent to upgrading your walls and ceilings from R-20 to R-40. Upgrading your walls and ceilings is a far bigger a task and there would be more damage done to your home. Upgrading your windows won’t leave you with large areas to repaint or damage to repair.

They also decrease relative heat loss, which increases thermal comfort inside your home.

So is it worth it? Yes. As long as you can comfortably afford it and you want to further insulate your home, upgrade the security and reduce external noise. It’s especially worth it if you have single glazing as it will be a dramatic improvement.

Triple Glazing U Value

To assess the performance of walls, flooring, windows or roofs, they are assessed in U value. U value is the rate at which heat escapes through a window. The lower the U value, the better the window. It’s crucial you consider U value when setting a long-term plan to reduce your carbon footprint.

Single pane traditional windows will typically have a U value of 5. A double glazed window will typically have a U value between 1.6 and 1.4. It has a low U value that is around 0.7. Although, the U value for all window types will be affected by:

  • The number of layers.
  • The thickness of the glass used for each pane.
  • The type of inert gas that is used to fill the space between the panels.
  • Location of your home and where the window is e.g. north or south facing.
  • If the frame has been insulated.
  • Type of coating on the window.

Noise Reduction

It’s great at reducing noise which makes it particularly good in busy areas, urban areas or homes near noisy locations such as an airport, train line or building industrial state.

If you already have double glazing, it’s unlikely that you’ll see the real value of upgrading if you live in a quiet area or small town where noise pollution is particularly low.

The thicker the glass, the better the noise reduction? The space between the panes can affect the noise reduction value. The bigger the spacing, and heavier the gas occupying the space is- the more noise reduction you’ll gain.

Does It Prevent Condensation?

Despite the energy efficiency factor, when weathers are cold outside and you are heating your home from within – condensation can appear.

It’s important to understand how condensation is formed. Condensation happens when water vapour becomes liquid. This happens when the air is cooled to its dew point or when it becomes so saturated with water vapour that it cannot hold the water anymore.

A dew point is the air temperature at which condensation happens, usually when warm air hits a cold surface. Therefore, if the warm air hits a cold window, condensation may form.

Alternatives to Triple Glazing

If you already have double glazing and want to upgrade your windows without having to invest too much money, what actions can you take?

  • Apply window caulk to prevent air from escaping.
  • Install awnings to block the sun.
  • Add window treatments to block drafts and sunlight.
  • Heavy lined curtains in the winter to reduce heat loss.
  • Apply weather strips for a cheap and efficient way to deal windows.

Will it fit into my Double Glazing Window Frames?

The windows are sealed units that come with the appropriate frame. Most window specialists will remove your current windows, including the frame, and dispose of them. The previous double glazed frame would not provide efficient support or space for your new windows.

How long does Triple Glazing Last?

There is no definite answer as to how many years they will last as it depends on various factors such as; where you live, weather conditions, the material used and how well maintained they are.

Many manufacturers say they has a lifespan of around 20 years. However, it can also range from 10-35 years. The windows may also last longer in terms of appearance but their energy efficient level will decrease as the gas escapes from the panels.

What’s Next, Quadruple Glazing?

Quadruple glazing actually already exists. You’ve maybe not heard of it because there have been some technical problems with this added layer of glass and it’s thermal insulation.

The four panes and three cavities not only make the window ridiculously heavy but it also reduces the amount of light that shines through. The reduced light shining through can also mean that it’s less energy efficient due to the reduction of sunlight absorption.

Quadruple glazing is also not necessary in the UK as double and triple glazing suit the UK climate. In colder countries such as Scandinavia and Sweden, they may try and find ways to improve quadruple glazing to suit their colder climate.

However, it’s likely that they will continue to develop the windows as they are through providing new coatings, materials that heat in the sunlight and realise at night and other technological advances.

We hope that we have answered all of your queries. If it doesn’t seem like the right investment for you, there are many alternatives you can take in order to upgrade your windows.

Many people often think of replacing their windows when they are looking to put their home on the market. The property market has been extremely competitive for quite some time now and homeowners have been using triple glazing as a way to difference themselves and add value to their home.


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