Double Glazing

Cornwall’s local home improvement specialists

for over 25 years

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Double Glazing

  • Double glazing is specifically designed to prevent excess heat from leaving your home, helping you save money on your energy bills. A material that reduces outside noise, double glazing is perfect if you live in a busy neighbourhood, or you’re simply looking for a quieter home environment.  

    Double glazing has two glass panes in one window with a space between them. The space is filled with argon gas, which has more density than air, and it functions as an insulator. Say goodbye to cold temperatures outside, as well as excess condensation on the inside of your windows – a frequent issue with single glazing. 

    Here at Britannia, we offer brilliant energy saving ratings on our double glazed windows. Opt for Super Energy Efficient glazing and triple glazing to bring your energy bills down even more. Double glazing is popular if you’re looking to invest in your home, add value to it and save money on energy in the long term. 

    Benefit from added security thanks to double glazing, as the frames are thicker and have panes which are more resistant to breakage. Thermally reinforced glass and security hinges also ensure our customers feel safe at home when choosing double glazing.


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    Lifetime Guarantee
    10-year manufacturer’s guarantee.

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    Tailor Made
    Classic windows tailor made to your exact specifications.

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    100% Satisfaction
    Award-winning customer service and after-care support.

  • Our industry-leading A+ rated double glazing provides ultimate safety and security, reduced noise pollution and high levels of thermal efficiency – saving you money on energy bills.

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    Flexible monthly payments

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    Interest free credit

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    Buy now / pay later

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    No finance required

Are you considering new double glazed windows for your home? Contact us today for a free quote or visit your local showroom to see our high-quality products for yourself.

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Is it worth replacing double glazing?

On average, double glazing has a lifetime of 20 to 30 years and like most things, as they age their efficacy starts to decline. If your windows aren’t functioning like they once used to, it could be worth considering getting them replaced. 

In the case of double glazing that’s under 10 years old, it can be more cost-friendly to have your windows repaired. We can offer a guarantee to fix your windows if they’re not performing to excellent standards. If you would like to replace your windows for the best degree of thermal efficiency, contact us here at CTG and we can talk you through the benefits and answer any questions you might have.

Does double glazing reduce condensation?

The simple answer is yes! Condensation happens when warm air makes contact with the windowpane, triggering the humidity to condense and create small drops on the window. Double glazing is comprised of two glass panes, divided by argon gas. Its density means there is very little heat transfer between each glass pane. The inner pane remains warm and close to room temperature, even if the outside pane is freezing cold. 

As there is less contrast between the cold glass and warm indoor air, you can awake on a chilly morning to a lot less condensation than in the case of a single glazed window.

What is double glazing?

As the name suggests, double glazing differs from single glazing; the former has two panes of glass whilst the latter has one. The double glass panes sit in a window frame with a space between them. We put argon gas between the two panes of glass to help with insulation. As argon is dense, it’s much more challenging for heat and sound to transfer between the panes, which means thermal insulation, a warm home and a smaller energy bill at the end of the month.

What is the best gap for double glazing?

Double glazing ensures noise stays out and heat stays inside, thanks to the gaps between each glass pane. The gap is filled with a dense gas, argon, which prevents cold air and noise penetrating the glass. 

We’ve identified that a 28mm thick unit, using a 20mm gap separating the twin glass layers is the optimum choice for double glazing; this is offered as standard at Britannia. We’re offering the most energy-efficient option that will allow you to save money on your bills and be eco-friendly, both of which are extremely important to us.

Does double glazing reduce noise?

It does indeed. Sound moves very easily through single glazing, but as our double glazing encompasses twin panes with an area filled with argon gas between each, less noise comes through. Argon is denser than regular air and has different soundwave properties; it will ensure your home is quieter, particularly if you live on a busy street, or you would simply like to benefit from increased peace and quiet. .

How long does double glazing last?

Double glazing will last around 20 – 30 years but can last even longer. Check your window quality to make sure it falls into the A-rated energy efficiency category and ensure the window is installed by experts, such as our team at CTG. This means your window frame will be of the highest quality, resistant to extreme temperatures, wind, rain and other British weather delights. 

It’s easy to tell when your double glazing isn’t functioning to its full potential. You will notice more condensation on each pane and the inner panes will be noticeably cold to the touch.

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We have various low cost finance options available. Get a quick quote and apply for finance at the same time.

Features and benefits

Guarantees you can depend on.

We have built up a great reputation over years of delivering a first class service and excellent products, all from our local, no nonsense all-about-you company.

From characteristic country cottages to contemporary town houses, we’re confident that our products will offer a style and finish to truly transform your home. Through constant innovation the quality, durability and security of our products is genuinely second to none. As a local company we are proud to offer British Standards BS7412/PAS24 for enhanced security.

We refuse to compromise on quality

Our windows are made from British Made, high quality MarinespecTM components, with up to 25 years anti corrosion. They are built specifically for the more exposed areas of corrosion, such as coastal environments to give you worry free performance beyond your guarantee.  We believe spending more on components is worth every penny, and sets us apart from our competitors.

State of the art fabrication for best quality

We have invested millions of pounds into one of the most state of the art manufacturing facilities in the UK.  This enables us to provide you with consistently high quality products at exceptionally good prices. Our loyal factory workers are well trained and take pride in their work, they really care about quality.  Our machines are maintained according to a rigorous servicing regime to keep them in top condition.

Superior energy efficiency

Our ‘A’ rated energy efficient and triple glazed windows are tested by the BFRC, which will save you money on your heating bills. By law your windows and doors have to meet strict thermal performance regulations but you can be rest assured that our products exceed current requirements.

Energy saving is incredibly important and so is keeping your fuel bills down. We are continuously looking for ways to make our homes energy efficient and one way is to choose new PVCu windows and doors. Not only will they help to keep your home warmer, they will reduce your energy loss.

Don’t just take our word for it!

Our suppliers conform to strictly controlled and independently monitored Quality Management Systems such as ISO 9001, to ensure that everything is done correctly and according to best practise.

Our windows are tested independently by British Standards for security, weather tightness and strength performance. This means that periodically, we have to send them to independent test houses, in order to be tested to destruction.

These are just some of the many standards the products in our vast range conform to. Needless to say we take the quality of our products very seriously indeed.


Made to measure

The styles available are endless and the choices to suit your home are bigger than ever before. Traditional, contemporary or modern; our versatile window and door designs will create the look you want to complement and enhance your home. If you want windows that are as individual as you, our range of coloured and woodgrain windows offer you fifteen different colours and finishes.

A local business that really cares about its customers

Our sales consultants, surveyors, admin team and installers really care about you and your home. They are highly trained, motivated and want to go the extra mile to do the best possible job. Our fitters will treat your home with care and respect and will take time to ensure that you are delighted with the end result.

With a local showroom including an extensive display and experts on hand you can see before you buy and meet the team!

An effortless purchase process

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