The Best Double Glazing Companies in the UK

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

If you’ve already got a head start on your research, you’ll know that the UK is home to an overwhelming amount of double glazing companies. But you’ve come to the right place. This article breaks down everything you need to know, from the best window companies to the best type of double glazed windows. Read on to find your home’s new perfect set of windows, or save yourself some time by using this simple quote tool to get bespoke double glazing quotes from window installers near you.

If you’re a little unfamiliar with the ins and outs of double glazing, we’ve added in some helpful information on the second half of this page. You can jump to this section by using the contents table below to clear up any uncertainties you may have.

In our guide to the Best Double Glazing Companies:

Best window companies

The top four double glazing companies in the UK are: Anglian Home Improvements, Everest, Safestyle UK, and Zenith Home Improvements. There are also a lot of independent double glazing companies — the prices of these will depend on where you live.

So, who will be installing your next windows? Check out the table below to see how the top 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


How did we pick the winners?

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 windows. 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 18,091 reviews on Trustpilot, it’s safe to say that Safestyle has frequently found itself under the microscope. Not only did it have the highest quantity of reviews, but a huge percentage of them rated the company as ‘excellent’

Zenith Home Improvement: Best for efficient installation – Zenith has garnered some negative reviews about the pressure that customer sales can impose on users. However, the reviews of the installation process were extremely positive

Independents: Best value for money – Which? recently found that 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.

Company breakdown

We know that you’re going to want more than just a few star ratings before investing in a company. So before you find yourself flitting from one company to another, make sure you check out each one in more detail below.

Anglian Double Glazing

Anglian is up there with the best of the best in the UK. Having helped over 1 million customers install double glazed windows, their reputation has certainly grown – but what exactly do they offer?

Window options: Anglian offers a wide range of window styles, including aluminium, timber, wood, and uPVC frames. On top of this, it offers double glazing, triple glazing, and secondary glazing.

Efficiency rating: Anglian windows come with an A to A++ efficiency rating for standard uPVC windows. All other windows score at least a B rating.

Anglian Double Glazing Reviews

Why Anglian? Customers have awarded Anglian top marks for the quality of its double glazed windows, as well as its installation service. Here’s what one testimonial had to say:

Testimonial user photo
Mrs Sherrie Bridge (Verified order on Trustpilot)

Easy process from start to finish. I used 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.

Why Not Anglian? Anglian has recently received a few negative comments regarding its customer service, throughout both installation and aftercare. Here’s one such comment:

Testimonial user photo
Mr C Low (Verified order on Trustpilot)

Windows are of great quality, and we have really noticed a difference. The cleanup afterwards could have been better, though, as we were left with broken glass on our patio.


  • 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

With over 53 years of experience in manufacturing and installing windows, Everest has certainly built up a reputation. They can work with you to create stylish, eco-friendly windows to improve your home – but what else is on the table?

Window options: Everest provides windows with aluminium, wood, and uPVC frames. These frames can also come in a range of different colours and finishes to suit your home. Everest also offers some of the most popular double glazing window styles, including casement and sash.

Efficiency rating: Its double glazing is A+ rated for uPVC windows, while triple glazing is A++. However, Everest doesn’t state the energy ratings for other double glazing on its website. If you’d like more information before committing with them, try contacting them for more information.

Everest Double Glazing

Why Everest? The majority of Everest’s reviews are situated at the ‘excellent’ end of the spectrum. The most positive comments are mainly reserved for the customer experience that Everest provides:

Testimonial user photo
Ms Mcgregor (Verified order from Trustpilot)

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! May not be the cheapest, but you really do get what you pay for!

Why not Everest? Despite the multitude of positive feedback, Everest has also accrued some negative comments on Trustpilot. These complaints are a mixture of poor / pushy salesman skills, and the expense:

Testimonial user photo
Annabel Dawes (Customer on Trustpilot)

Very aggressive sales tactics which made us feel very uncomfortable. We were told we didn’t have an option but to decide on the day or face losing the “best deal”. However, the installation process was smooth and undertaken to a high standard.


  • Windows have an A to A++ efficiency rating
  • 10-year guarantee on all new windows
  • A further 30 years guarantee against rot and fungus on timber windows/doors
  • Choice of 5 different window styles

X Cons:

  • Can be expensive (but worth the money)
  • 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 to just uPVC — but on the other, you’re dealing with experts in the specific field.

Window options: Safestyle UK offers a range of different window types and styles, including casement, sash, and bay windows — all of which can be tilt and turn. All its frames are uPVC, but are available in a range of finishes, such as white, cream, grey, black, oak, and rosewood.

Efficiency rating: According to Which?, all of Safestyle UK’s windows are A-rated. Its Legacy sliding sash and Eco Diamond windows are also both endorsed by the Energy Saving Trust.

Safestyle UK reviews

Why Safestyle UK? Unlike with some window manufacturers, customers praise Safestyle for its customer service and communication skills.

Testimonial user photo
Safestyle customer Bibi Sanchoo, via Trustpilot

I am a returning customer. We had our windows in our house replaced with Safestyle, and they were very professional. The sales consultant, surveyor, and installers were excellent! Great customer service. They followed up after the job was finished. I would highly recommend!

Why not Safestyle UK? The negative reviews of Safestyle all share a lot of similarities. According to customers, the sales pitch and installation of the windows tends to go swimmingly – it’s the aftercare stage that lets Safestyle down from time to time, and it’s something that the company might need to work on.

Testimonial user photo
Safestyle customer Jill, via Trustpilot

Salesman was extremely helpful, after sales were very quick to try and sell me more products after my front door was installed. Aftercare has been non-existent. Twice reported issues that I have with my front door – nearly three weeks later, not had a single response.


  • Excellent communication during purchasing process
  • Promises to beat competitor prices
  • Removes old windows and recycles 95% of them

X Cons:

  • Poor communication after transaction
  • Unresponsive to customer feedback
  • Limited to just uPVC

Zenith Double Glazing

Zenith has been at the forefront of the home improvements industry for decades. The company focus primarily on uPVC windows, so if it’s wooden or aluminium windows you’re after, you might have to try elsewhere.

Window options: Although Zenith focuses solely on uPVC, they provide a range of different colours to choose from.

Efficiency rating: Are you environmentally conscious? Luckily for you, Zenith’s EcoTherm range of A-rated energy efficient windows is made from a recycled uPVC plastic.

Zenith Reviews

Why Zenith? Zenith has received mixed reviews on a lot of sites. The more positive reviews are reserved for its installation service:

Testimonial user photo
Mr R McKinlay (Verified order on Trustpilot)

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.

Why not Zenith? Other reviews, however, are quite negative about Zenith’s aftercare service. Some of these comments refer to pushy sales tactics, while others refer to a lack of aftercare.

Testimonial user photo
Mr Puncher (customer on Trustpilot)

The product and installation were great but the sales calls after installation has reached epidemic proportions.


  • Despite negative reviews online, they reply to each complaint
  • Windows made from recycled plastic
  • 15-year warranty with Carefree Agreement

X Cons:

  • No wood or aluminium frames
  • Has received more complaints that other major manufacturers

Independent Double Glazing Companies

Do you find big brand names a little intimidating? You’re not alone. Perhaps it’s time to consider some reliable, independent installers near you. It goes without saying, but the best independent company near you will depend on where you live. Furthermore, the quality will always vary, so it’s best to do some digging around.

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.

Double glazing frame options

It’s always good to cover the basics, so let’s start off at the beginning – what window material would best suit your home? To help you with this decision, we’ve listed the most popular types of double glazed windows below.

uPVC – Otherwise known as Unplasticised Polyvinyl Chloride, this is the most popular type of material for double glazed windows. These windows rose to fame in the 1990s when people realised how low maintenance they could be. All they need is a wipe down every now and then to keep them looking spick and span.


  • Low maintenance
  • Weather resistant

X Cons:

  • Appearance isn’t as nice as other materials

Aluminium – The first material to be experimented with when building double glazed windows, aluminium still holds up today! Aluminium frames are weather resistant, meaning they require very little maintenance to retain their fresh look. They are also incredibly strong, enabling you to improve your home’s security. However, they are also the most expensive option, so you might want to put aside a few pennies before investing.


  • Low maintenance
  • Weather resistant

X Cons:

  • Very little insulation benefits
  • Expensive

Wooden Wooden windows are the most environmentally-friendly option. This is one of wood’s main selling points, as well as its traditional look. However, wooden window frames are also the most high maintenance option, as it can be susceptible to rot. That said, if looked after properly, they can last a massive 60 years – making them a worthwhile investment!


  • Very elegant
  • Can last up to 60 years

X Cons:

  • High maintenance
  • More expensive than uPVC

Types of double glazed windows

Now we’ve sorted the style, it’s time to figure out what type of window will be best for your house. The type of window, plus the material that you decide on, will affect the overall price, but we’ve included a calculator at the end of this section to help you out with the maths.

Casement – You’ll probably be familiar with casement windows, as they’re the most common style of double glazing in the UK. These windows are attached to their frame by one or more hinges at the side, and typically open outward using a handle. Casement windows are often held open in position using a metal bar with hooks, known as a casement stay.


  • Ventilation – the angled window can catch breezes
  • The most energy-efficient of all window types

X Cons:

  • More expensive than other types of windows
  • Easier to break as the hinges age

casement window

Bay – Bay windows project outward from the main walls of a home. Three or more windows usually project at 45° or 90° angles, to form a box bay window. This type of window works particularly well for smaller properties.


  • Add lots of light and space to a room
  • Add value to your home

X Cons:

  • Expensive to install
  • If a window needs to be repaired, the entire unit often needs replacing

bay window

Sash – Sash windows have one or more movable frames, which open by sliding via a mechanism attached to the frame. These windows are particularly popular with more traditional, period properties.


  • They can add value to your home
  • Energy efficient

X Cons:

  • Lack of ventilation
  • Can be easier to break into
sash window

Tilt and turn – Tilt and turn windows open in two different ways. The ‘tilt’ functionality of the window allows it to be tilted inwards (or outwards) at an angle. Meanwhile, the ‘turn’ functionality allows the window to swing inwards (or outwards) for a wider opening option.


  • Add extra ventilation
  • Better air-seals provide better insulation

X Cons:

  • More expensive
  • Better for larger properties, as inward opening windows take up more room

tilt and turn

Dual turn – Dual turn windows consist of two panes of glass that tilt separately outwards. These window panes can also rotate 360°, allowing you to reach both sides of the glass from within your home – especially handy for cleaning.


  • Easy to use and maintain
  • Add extra ventilation

X Cons:

  • More expensive
  • Better for larger properties, as inward opening windows take up more room

So there you have it — the main types of frames and materials. Each home will suit different windows and materials, depending on its size, location, and all-round style. But that’s for you to judge.

Worried about your savings taking a hit? You can use our double glazing cost calculator below to work out just how much your windows will cost you.

And if you want to see how much you could save, complete this form to receive tailored quotes for brand new windows.


Should you use a local double glazing company?

Many homeowners do go for this option, and we can’t say we blame them. Local companies are usually higher quality, as small firms rely more on reputation to attract customers. You’ll also find that local installers offer a more ‘personal’ service , as well as competitive prices.

How long does double glazing last?

Depending on the quality of the windows, it can have a lifespan anywhere between 15 and 35 years. Warning signs for needing to get your window replaced include experiencing drafts from your window, and condensation between the panes.

How does double glazing work?

Double glazed windows are made up 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, so is much more effective.

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 number of windows that you go for. Installing new double glazing in a two-storey house will cost about £5,000 to £8,000 in total.

How much can you save with double glazing?

By switching to double glazing with an energy efficiency of A+, you can save up to £110 per year. Double glazing improves your property’s insulation, meaning you’ll rely less on your central heating to warm your home.

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%.

How did you pick the best double glazing companies?

With so many to choose from, this wasn’t an easy task.

We combined thousands of verified Trustpilot reviews with in-depth market research. We also focused on what our readers tell us matter most to them when choosing a new window installer: these factors include the quality of the windows, the professionalism of the installer, value for money, customer service, the window warranty, and energy efficiency.

What’s next?

Feeling ready to journey through this window of opportunity? Once you’ve settled on an installation company, a style of window and material, it’s time to experience what double glazing can do for you and your home.

Hopefully you now feel more comfortable with the ins and outs of double glazing. But if you need just a little more guidance, you can contact our local, professional installers, who will help answer any questions you may have.

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.