Triple Glazed Windows


Chris Farrington, Cameron Gunn and Lee Manning of ReSolve Advisory Limited were appointed as Joint Administrators of Everest 2020 Limited (“Everest”) on 24 April 2024.

If you have any queries in relation to the business and/or administration, please contact

Chris, Cameron and Lee are licensed to act as Insolvency Practitioners in the United Kingdom by the Institute of Chartered Accountants in England and Wales and, along with their staff, act without personal liability at all times.

Licenced Insolvency Practitioners who are appointed as Administrators, and their staff, act as agents of the company over which they are appointed. A list of ReSolve’s licensed Insolvency Practitioners can be found on our website.

Triple glazed windows

Triple Glazed Windows

For a Warmer, More Energy-efficient Home

  • Market-leading energy-efficiency
  • Security exceeds British Standards
  • Industry-leading low 0.80 U-value
  • A++ energy rating to help reduce energy bills

Triple Glazed Windows from Everest

Triple glazing has three panes of glass held together in a glazing unit with two insulating air gaps that slow down the thermal transfer of cold or heat through the unit. The deeper the unit, the more insulating the glazed unit is. Standard double glazed units have a unit depth of 28mm, whilst Everest triple glazing is a substantial 44mm deep.

Everest triple glazing is one of the highest performing glazing units on the market with an industry-leading 0.80 U-value making it ultra energy efficient. Choosing energy-efficient Everest windows can help lower your energy bills and reduce your carbon footprint.

We only use the best components to make superior quality windows and pay attention to all the details of our frames. Market-leading corner welds, a PCE gasket with a superior weather tight seal, an extreme multi-point locking system with powerbrace keeps for enhanced security and a trickle vent which has noticable noise reduction on previous vents.

Choose from uPVC window frames, wooden windows and aluminium windows. We also offer a variety of designs, including our most popular casement window frame, Tilt and Turn and bay windows. Everest triple glazing is available in a wide range of options suitable for all types of houses such as modern, traditional and period properties.

Triple Glazed Window styles

Casement Windows →

Our most popular window with excellent performance and versatility.

Tilt & Turn Windows →

Opens inwards for easy cleaning and tilts for secure ventilation.

Bay Windows →

Create a sense of space with panoramic views and more sunlight.

Market-Leading Energy Efficiency

With the introduction of our new window range, we are offering superior energy efficiency, market-leading U-values and a drive towards sustainability that has not been widely available in the UK.

As the Future Homes Standards are introduced, the energy efficiency of a home and U-values for windows will become more important. At Everest, we believe that triple glazed windows will become a requirement in all new build houses as the standards for the fabric structure of buildings keep increasing.

Everest uPVC triple glazed windows and double glazing windows have a low U-value with triple glazing achieving a market-leading 0.8. The frame is made with recycled uPVC and most of the window can be recycled to reduce the impact on the environment.

By choosing Everest windows now, we will help you to future-proof your home with the best products for energy efficiency and the environment:

  • 0.80 U-value achieving the proposed Future Homes Standard
  • PAS 24:2022 highest security standards
  • Recycled uPVC used in frames, a more sustainable choice than virgin uPVC
  • The uPVC window can be recycled, meaning less impact on the environment

Everest Triple Glazing Units


Low U Value

Energy Saver

Best for energy efficiency

Ultimate Triple Glazing

Ultimate Triple Glazing

The outer pane reduces solar heat gain and provides high insulation, this combined with the centre pane and Low E inner pane reflects heat back into the room.


Tick  Low U Value
Tick  Reduced solar gain
Tick  A high degree of neutrality

Download Tech Sheet (44mm)
Download Tech Sheet (32mm)


U Value (No Georgian Bars): 0.80

G Value: 0.19

Window Energy Rating: C

Glass Panes

Outer Pane: 4mm Toughened SKN176

Centre Pane: 4mm Toughened Clear

Inner Pane: 4mm PlaniTherm One

Decorative Glazing Options

Georgian Bars: Not available

Obscure Glass: Not available

Leaded Glass: Not available

Energy Saver Triple Glazing

Energy Saver Triple Glazing

The outer pane allows solar heat in while the centre and inner panes both reflect heat back into the room.


Tick  Highly energy efficient (A++ Rated)
Tick  Neutral and clear appearance
Tick  Increased level of solar heat gain

Download Tech Sheet (44mm)
Download Tech Sheet (36mm)
Download Tech Sheet (32mm)


U Value (No Georgian Bars): 0.91

G Value: 0.40

Window Energy Rating: A++

Glass Panes

Outer Pane: 4mm Low Iron

Centre Pane: 4mm Toughened Low E

Inner Pane: 4mm Low E

Decorative Glazing Options

Georgian Bars: Internal only

Obscure Glass: Optional

Leaded Glass: Optional

Is triple glazing better than double glazing?

Based on U-values, Everest energy efficient triple glazing is three times more energy efficient than old double glazing and just over one-and-a-half  times more efficient than Everest energy saving double glazing.

Double GlazingTriple Glazing
Highest Energy RatingA+A++
Lowest U Value1.200.80
G Value0.460.40
L Value00

The difference between double and triple glazing

Windows Fully Bespoke to Your Home

With thousands of options to choose from, Everest windows are designed to meet your needs.

Everest coloured window frames


Over 20 stunning colours including woodgrain finishes on uPVC which look like real timber.

View Window Colours

Glazing on an Everest window


Customise your windows with a choice of glass and glazing, including obscure, decorative, noise-reducing, double glazing or triple glazing.

View Glass Options

Everest window furniture

Furniture & Hardware

Our window handles and furniture are available in a choice of colours, so you can create the perfect look for your property.

View Window Furniture

Triple Glazing FAQs

  • +
    Do triple glazed windows reduce noise?

    Many people mistakenly think that triple glazing is more soundproof than double glazing because there are three panes of glass. This is incorrect, as to reduce the transmission of soundwaves a combined approach of disruption and reduced transference is necessary.

    If noise pollution is important for you we recommend our Double Glazing noise reduction windows.

    Read more: How to soundproof windows...

  • +
    How long does triple glazing last?

    Triple glazing lasts for around 20 years but does vary depending on the quality of the window units and the quality of the installation.

    Of course, windows can last far longer than their predicted lifetime and many houses have windows that are over thirty years old - if they've been well-maintained.

    It also depends on where the windows are positioned in a property. For example, a south-facing window that gets a lot of sun or a coastal facing property will have a shorter lifespan due to excessive weathering.

  • +
    Is Triple Glazing worth it?

    Everest triple glazing is five times as efficient as old double glazing and only costs 10-20% more than new double glazed windows.

    The superior efficiency of triple glazing can help to create a house that reduces carbon emissions and uses less energy to heat.

    Triple glazing also creates more comfort in your home with less cold spots next to windows.

    Ultimately, it’s a personal choice based on your own requirements. But, as U-values become more important for homes and can contribute to better EPC ratings, triple glazing is becoming more popular in the UK.

  • +
    How much does triple glazing cost?

    When buying new windows there are a variety of options that make a difference to how much your new triple glazing windows will cost.

    Comparing prices from different suppliers needs to be on a like-for-like comparison of quotes. At Everest, our prices include everything from the window, all furniture and fittings, installation to waste removal and recycling of your old windows.

    Everest triple glazing costs 10-20% more than double glazing.

    The average price for triple glazing windows is anything between £660 to £4,320 per window, depending on the different options, such as bay windows are 150% more than casement window frames.

    Read more: How much does triple glazing cost...
  • +
    What are the disadvantages of triple glazing?

    There are several common misconceptions about triple glazing that have been perceived as 'disadvantages'. However, all the raised 'cons' are just misconceptions.

    The reality is that triple glazing is a superior product in comparison to single and double glazed windows, especially for energy efficiency, and there are no disadvantages.

    Read more: The disadvantages of triple glazing...

  • +
    What window colours are available?

    At Everest we offer a beautiful range of colours and natural woodgrain finishes, so there is a perfect colour to suit every property. Colours range from the traditional white uPVC finish, through to Chartwell Green and ultra-contemporary anthracite grey or black. Add a modern twist to your windows, with dual colours, complementing the inside and outside of your home.

    Read more: Everest window colours...

  • +
    What types of glass are available for windows?

    Not all glass is the same. Glass comes in varying thicknesses, clarity levels and coatings and there are several types of glass you can choose for your windows and doors depending on the needs and problems in your home. Whether it's energy efficiency, reducing external noise or protecting furniture from UV damage we have the right glass to solve the problem.

    Read more: Glass options for windows...

A white casement window in a kitchen with white handle multi-point locks

Why Choose Everest Windows?

Energy Efficiency & Sustainability

When you choose Everest, not only do you make your home warmer and reduce your energy bills, but you also reduce your CO₂ emissions by consuming less energy to heat your home. We strive for an environmentally friendly manufacturing process and our new windows can be recycled at end of life to reduce the impact on the environment. We are committed to superior energy efficiency, market-leading U-values and a drive towards sustainability that has not been widely-available in the UK.

Quality Is in The Details

We source the best components and pay attention to the details that make the difference. Our window frames have almost invisible corner welds and superior weather tight seals. An extreme multi-point locking system for enhanced security that meets PAS 24:2022 and Secured By Design standards. And a trickle vent which has been acoustically tested to show an improvement of noise reduction from our previous vent.

Light shining through a anthracite grey casement window onto a desk with a laptop

Case Study

uPVC Triple Glazed Windows

5 star rating 5 out of 5 on TrustPilot

I'm so impressed with how warm the house is now in the winter with the triple glazing, there is a definite difference from before. Mr G, Lincolnshire


Everest Window Reviews

Everest Buying Guides

When replacing windows, always choose a style and material that is in keeping with the architectural style and age of your house. Read our buying guides that will help you to choose the right windows for your home.

Is triple glazing worth it

Is triple glazing worth it?

Discover the benefits of installing triple glazing and whether it's better than double glazing.


Double glazing vs triple glazing

Double glazing vs triple glazing

We carried out an experiment to demonstrate which type of glazing is better.


How to choose replacement windows

Different Types of British Houses

Choose windows based on the age and architectural style of your house.


Start Your Project Today...

Book your free quotation appointment with one of our local expert consultants who will:

  • Provide an accurate, no-obligation quote
  • Offer ideas and practical solutions
  • Show you samples of our products
  • Take all necessary measurements

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