The Best UK Double Glazing Companies in 2020

Double glazed windows


Everest and Safestyle UK have the highest rating on Trustpilot

44% of people buy double glazed windows to reduce their energy bills

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Once you’ve installed double glazing at home, you’ll be kicking yourself for not doing it sooner.

Double glazing can provide warmth, safety, and even a bit of peace and quiet. In fact, Which? recently found that only 51% of people who bought double glazed windows said that they bought it to make their home warmer – another 44% did so to reduce their energy bills.

If you’re on the hunt for the best double glazing, read on to learn about the best local and national companies. Alternatively, you can save yourself time by filling out this short form to receive quotes from local window installers.


What’s on this page?

Best window companies

Let’s get straight to the point. The top four double glazing companies in the UK are Anglian Home Improvements, Everest, Safestyle UK, and Zenith Home Improvements. If you’re a little intimidated by big brands, towns and cities across the country are also home to a number of excellent local installers – but more on them later.

Check out the table below to see how double glazing window companies compare. These ratings are based on a combination of real user scores and our own independent research.

Double glazing company
Best for
Trustpilot rating
Anglian Home Improvements
Quality of windows

Warranty period

Safestyle UK
Customer satisfaction

Zenith Home Improvements
Efficient installation

Independent Double Glazing Companies
Best value for money


Anglian: Best for quality of windows – Anglian guarantees its window frames will last for 10 years, and its sealed units for a further 15 years. They are also all A+ rated.


Everest: Best warranty period – Everest offers a 10-year guarantee on all of its windows. On top of this, it also offers a guarantee against condensation on certain windows, and a further 30-year timber window guarantee. A lifetime guarantee is also offered for flaking and discolouration on white uPVC.


Safestyle UK: Best for customer satisfaction – With 19,393 reviews and counting on Trustpilot, it’s safe to say that Safestyle has frequently found itself under the microscope. Fortunately, a massive 84% of these reviews rated the company as ‘excellent’.


Zenith Home Improvements: Best for efficient installation – Zenith has garnered some negative reviews, with many users unhappy about the aggression of its customer sales team. However, the reviews of the installation process are extremely positive.


Independent Double Glazing Companies: Best value for money – In a recent study by Which?, a whopping 83% of people said they chose independent double glazing installers over big brand names. This was due to their locality, the fact they weren’t intimidating, and the strength of their reputation.

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National company breakdown


Anglian Double Glazing

Anglian offers a wide range of window styles, all of which are available with aluminium, timber, and uPVC frames. On top of this, it offers double glazing, triple glazing, and secondary glazing.

If energy efficiency is your main concern, Anglian’s standard uPVC windows have a rating of A to A++. All other windows score at least a B rating.


Customer reviews

Customers have awarded Anglian top marks for the quality of its windows and installation service. Here’s what one keen customer had to say:

“Easy process from start to finish. I used the online chat, and was booked in within a few days. The guy was friendly and non-pushy. We then received phone calls and emails keeping us updated all the way. Fitted and very happy.” – Mrs Sherrie Bridge (Verified order on Trustpilot)

Despite the list of happy customers, Anglian has also received a few negative reviews regarding customer service. These comments cite problems with communication throughout both installation and aftercare.


  • Windows have an A to A++ efficiency rating
  • If you find cheaper windows elsewhere, they’ll match the price
  • 10-year guarantee

X Cons:

  • More expensive than other companies
  • Some issues with customer service
  • Don’t offer as many guarantees as other companies

Everest Double Glazing

Everest offers some of the most popular window styles, all in a range of materials – if you’re investing in double glazed windows for a more energy efficient home, then look no further. Everest’s double glazed windows are A+ rated for uPVC windows, while triple glazing is A++ for all windows.


Customer reviews

80% of Everest’s reviews on Trustpilot are rated ‘excellent’. The most positive comments mainly refer to the customer experience that Everest provides:

“Amazing service from the team right from the start. Sales, aftercare, and above all, the installation chaps! Such an amazing finish on the windows, very minimal mess to clear, and amazing personalities! It may not be the cheapest, but you really do get what you pay for!” – Ms Mcgregor (Verified order from Trustpilot)

As is often the case, good quality results in a more expensive bill – something which proved to be customers’ main concern. Poor/pushy salesman skills have also had a negative impact on Everest’s customer ratings on Trustpilot.


  • Windows have an A to A++ efficiency rating
  • 10-year guarantee on all new windows, and an additional 30 years against rot and fungus on timber windows and doors
  • Choice of five different window styles

X Cons:

  • Can be expensive
  • Salesmen can be pushy, according to some customer reviews

Safestyle UK

Safestyle UK focuses purely on uPVC windows and doors. On the one hand, this limits you solely to uPVC – but on the other, you’re dealing with experts in a specific field.

Safestyle UK offers a range of different window styles, including tilt and turn. Its Legacy sliding sash and Eco Diamond windows are both endorsed by the Energy Saving Trust, so if you’re particularly eco-conscious, Safestyle is a good option.


Customer reviews

84% of Safestyle’s customer reviews rated the company as ‘excellent’. And unlike some other window companies, Safestyle has been praised for its customer service and communication skills.

According to customers, both the sales pitch and actual installation of the windows tend to go swimmingly.


  • Excellent communication during the purchasing process
  • Promises to beat competitor prices
  • Removes old windows (95% of the windows they remove are also recycled)

X Cons:

  • Limited to just uPVC

Zenith Double Glazing

Zenith also focuses on uPVC windows only, so if you’re after wooden or aluminium windows, you’ll need to look elsewhere.

Think of yourself as a bit of an eco-warrior? Well, you’ll be pleased to know that Zenith uses recycled uPVC plastic for its A-rated EcoTherm range of windows.


Customer reviews

Zenith has received mixed reviews on a lot of sites. The more positive reviews applaud the company’s installation service:

“Very efficient installation service and high specification windows and doors. Completed to my requirements and satisfaction. I can already benefit from the heat conservation and warmth indoors without having to put my central heating on when colder nights have started.” – Mr R McKinlay (Verified order on Trustpilot)

Other reviews, however, are quite negative about Zenith’s customer service. Some of these comments refer to pushy sales tactics, while others mention a lack of aftercare.


  • High response rate to complaints
  • Windows made from recycled plastic
  • 15-year warranty with Carefree Agreement

X Cons:

  • No wood or aluminium frames
  • High level of complaints on Trustpilot

Best local window suppliers

Do you find big brand names a little intimidating? You’re not alone.

Each independent window company will bear plenty of wonderful quirks that differentiate them from big brand names. Plus, you can be confident that most of these independents will be approachable, and offer a service that’s both good quality and good value for money.

Check out our top local window companies for the UK’s major cities below:

Each independent company will bear plenty of wonderful quirks that differentiate them from big brand names. However, you can be confident that most of these independents will be approachable, and offer a service that’s both good quality and good value for money.



Trustpilot rating ( /5)
Number of reviews
Key features
• uPVC frames only
• Wide variety of window styles
• Offers a double glazing repairs service
• uPVC frames only
• Offer a wide variety of window styles
• A keen focus on energy efficiency (all windows are A-rated)
• uPVC frames only
• Provides a wide set of window styles
• Secondary glazing can also be provided
• A really wide variety of windows
• Variety of different material frames
• 10-year guarantee
• Wide variety of styles and materials
• 10-year guarantee



Trustpilot rating ( /5)
Number of reviews
Key features
• uPVC windows only
• 10-year guarantee
• A keen focus on energy efficiency – all their products are ‘A’ rated
• uPVC frames only
• A collection of styles to choose from
• A wide range of styles and materials
• 10-year guarantee
• Will also repair and replace windows



Trustpilot rating ( /5)
Number of reviews
Key features
• uPVC windows only
• 10-year guarantee
• A keen focus on energy efficiency – all their products are ‘A’ rated
• uPVC, timber and aluminium frames available
• Claim to be customer-focused, rather than sales-driven
• uPVC and aluminium windows only
• Customers are able to apply on finance



Trustpilot rating ( /5)
Number of reviews
Key features
• “No salesmen, just tradesmen” policy
• 10-year guarantee
• Claim to strive for honest customer service
• uPVC windows only
• Customer satisfaction is their priority
• uPVC windows only
• Family run business
• Offers repairs as well as installation

As you can see, based on these examples, local suppliers are often better places to provide personal customer support than their national competitors.

Being more attentive, with less pushy sales tactics, local suppliers are certainly raising the bar.


What double glazing frame options are available?

There is a range of materials you can opt for, including uPVC, aluminium, and timber. Whilst timber is the most traditional material, uPVC is lower maintenance. If you’re looking for a more modern look, aluminium might be your best bet.


How long does double glazing last?

Typically, double glazing lasts about 20 years. If your windows are letting in drafts or have condensation between the panes, this is a sign that they might need replacing.


How does double glazing work?

Double glazed windows consist of a frame that is fitted with two panes of glass. Between the two panes is a tiny gap, filled with air or a natural gas such as argon. Both the air and the gas act as a blanket of insulation, keeping in the heat. The gas, however, is heavier than air, making it much more effective.


How much can you save with double glazing?

By switching to double glazing with an energy efficiency of A+, you could save up to £145 per year.


Is double glazing worth it?

Yes! Double glazing can improve your property’s energy efficiency, as well as its security. It can even block out any unwanted noise from outside. And better still, new double glazing has been found to increase a property’s market value by up to 10%.


What type of glass is used for double glazing?

There are a few different types of glass you can opt for. Annealed, tempered, and laminated glass are the basic options, which all vary in thickness. You can also get coated (low E) windows, which further decrease the amount of heat that passes through windows.

Standard double glazing reduces the amount of noise you hear by up to 75%. But if you’re after an even bigger noise barrier, noise-cancelling windows might be the way to go.


How much does double glazing cost?

The average cost of double glazing is between £400 and £600 per window. The precise amount comes down to the style, size, and amount of windows that you go for.

Use our double glazing cost calculator below to work out just how much your windows will cost you – and don’t worry, there are double glazing grants available.


What’s next?

Hopefully, you now feel more comfortable with the ins and outs of double glazing. If you’re still unsure about which company to go with, simply fill out our short form. Once you’ve completed a few simple questions, our professionals will be in touch with installation quotes for you to compare. Gone are the days of worrying about windows!

Beth Howell Writer

Beth is The Eco Experts’ newbie. She’s keen to use her writing skills, and passion for green living, to help the environment. Whether you’re after a new boiler, or just interested in how solar panels can improve your home, she’s got your back.