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A double glazing window with sheer curtains draped over it and a potted plant sitting on the window sill.

Image credit: Pexels/Pixabay

When it comes to making your home more energy efficient, double glazing windows are a solid investment. Built using two panes of glass with a layer of insulating gas in between them, double-glazed windows help to keep more heat inside your home in the winter, which in turn can see you lower your energy bills by up to £235 annually, as well as your household emissions. 

There are a great deal of companies in the UK that make and install double glazing windows, so choosing the right one for your home can be challenging. In this guide, we’ve reviewed some of the top window fitters in the country to help you decide.

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Best double glazing windows brands

We have selected five companies that manufacture and install double-glazed windows. We reviewed their products and determined what makes each of them unique and why they can help your new window planning:

  • Best guarantee: Everest
  • Most eco-friendly: Safestyle
  • Best range: Anglian Home Improvements
  • Most affordable: Britelite
  • Best financing options: Britannia

Best guarantee: Everest

Everest double glazing windows white uPVC

Image credit: Everest

  • Energy efficiency: A+ for uPVC casement, A or B for timber and aluminium frames
  • Available materials: uPVC, wood, and aluminium
  • Available styles: Casement, sash, tilt and turn and bay 
  • Guarantee options: 10 years standard, 20 years on uPVC and lifetime guarantee available for an extra cost

Everest creates and installs truly bespoke double glazing windows that are made to fit. The windows are available in uPVC, aluminium and wood frames and come in a variety of colours and designs, including sash, casement and secondary glazing. 

All Everest uPVC casement double glazing windows are rated A+ for energy efficiency and can help you reduce draughts and save money on energy bills. Another advantage of Everest windows is that you can choose from an unmatched number of glass options, including obscure, noise-reducing and toughened. 

Everest windows are Secure by Design (SBD) certified and validated by the police initiative. They have also been awarded Quiet Mark accreditation and can help reduce noise by up to 40dB. 


The average price for a double glazing Everest window is between £500 to £3,200 per window. The cost depends on the type of window (casement, sash or bay), the frame material and the frame colour.

Type of windowEstimated price
Sash30% more than casement
Bay100% more than casement

Aluminium frames are 25% more expensive than uPVC but 25% cheaper than timber. Grey and wood grain uPVC are also about 10-15% more expensive than white uPVC. 

What we think

When it comes to guarantee options, no company beats Everest. The company offers three levels of warranty. There is a standard guarantee of 10 years that covers all parts and materials (as long as the product is correctly maintained). All uPVC Exclusives have a 20-year guarantee that also covers condensation, fogging and discolouration. Lastly, Everest also offers a lifetime guarantee at an extra charge. While Everest windows are unlikely to be the cheapest in the market, the quality of the windows is exceptional.

Read our full Everest review

Most eco-friendly: Safestyle

Safestyle double glazing windows green

Image credit: Safestyle

  • Energy efficiency: A-rated 
  • Available materials: uPVC
  • Available styles: Casement, sash, tilt and turn and bay
  • Guarantee options: Standard 10 years on all windows

Safestyle is one of the UK’s most popular choices for double glazing windows. The company manufactures and installs high-quality, energy efficient windows and offers casement, sash, tilt and turn and bay designs. There are also several available finishes (including many wood grain-effect options like rosewood and oak).

A big advantage of choosing Safestyle is the company’s eco-friendly practices. It aims to reuse or recycle as much material from old windows as possible. When the company replaces windows, it reuses what it can in its own manufacturing process. Everything else is sent to a professional recycling centre. It also ensures journeys to and from these recycling centres are as efficient as possible by compacting the material so lorries can carry more with every trip. Through this process, Safestyle also offers customers a discount on replacement windows by buying back their old windows. 

Safestyle offers a standard 10-year guarantee on all its windows. This includes the repair or replacement of any faulty products. All Safestyle installers are Trust Mark certified, and the company is also accredited by the Glass and Glazing Federation and the Fenestration Self-Assessment Scheme

Safestyle double glazing windows are affordable (the company will price match any other quotes) and have a wide range of financing options, including 24-month interest-free credit, buy now and pay in 12 months and low-rate monthly finance. 


A double glazing Safestyle window costs between £250 and £1,050, depending on the finish and style. The type of glass and project scope will also affect the quote.

Type of windowEstimated price
Tilt and turn£400-£675
Bay£400+ per section

What we think

Safestyle is an excellent double glazing window option for eco-conscious customers. The company is not just leading the way in energy efficiency; it also has several windows that are endorsed by the Energy Saving Trust and recycles over 16,000 tonnes of materials every year (most of them old windows that have been replaced). In fact, the company allows you to calculate the price of your old windows and doors and discount the amount from your new products.

Read our full Safestyle review

Best range: Anglian Home Improvements

Anglian double glazing windows white

Image credit: Anglian Home Improvements

  • Energy efficiency: A or A+ for double glazing
  • Available materials: uPVC, wood and aluminium
  • Available styles: Casement, flush, bay, tilt and turn, cottage and sash windows.
  • Guarantee options: Standard 10-year guarantee and 15-year sealed unit guarantee

Anglian has over 50 years of experience in double glazing windows and doors. The company has an impressive range of styles and materials, including casement, flush, bay, tilt and turn, cottage and sash windows in uPVC, wood and aluminium. They also work with several glass types and have a wide range of accreditations, including Made in Britain, Secured by Design and Recovinyl Plus. 

Anglian windows are made from durable materials and can withstand forced entry. They also include a great choice of handles, locks and finishing furniture. 

Delivery and installation are included in all price estimations. Anglian offers a standard 10-year guarantee (labour and parts) for all windows and a 15-year sealed unit guarantee (for gas-filled products including double glazing). You can also spread the cost of your new double glazing windows with a low-rate finance plan from a 9.9% APR variable.


Every Anglian window purchase and installation will differ depending on your home’s size and the materials and style of your selected products. To provide an accurate cost, Anglian will send an inspector to measure your home. The average prices, however, are as follows:

Type of windowEstimated price

What we think

Anglian offers high-quality double glazing windows and has good guarantee and financing options. Where it stands out, however, is in its range of available products. With casement, flush, bay, tilt and turn, cottage and sash designs, all available in uPVC, aluminium, composite and wood, there is no match for the number of styles offered by Anglian. The company’s prices are also competitive, and you can generally get a personalised quote in less than seven days.

Read our full Anglian review

Most affordable: Britelite

Britelite double glazing windows white bay

Image credit: Britelite

  • Energy efficiency: A-rated (for all double and triple glazing windows)
  • Available materials: uPVC and aluminium
  • Available styles: Casement, French casement, flush sash, sliding sash and tilt and turn
  • Guarantee options: 10-year guarantee (includes registration with FENSA)

Britelite produces high-quality double and triple glazing windows, focusing on security and energy efficiency. The products are made to measure, professionally installed and instantly registered with FENSA once paid.

The company offers windows made in uPVC or aluminium, and in casement, French casement, flush sash, sliding sash and tilt and turn styles. You can explore the different designs on their website and request a quote without having a technician visiting your home. 

All Britelite double and triple glazing windows are A-rated for energy efficiency and can help you minimise heating costs. The company also uses Low-E glass, which features novel thermal barrier technology for better insulation. 


Britelite windows are very affordable. The downside is that there aren’t many financing options – just monthly payments with a representative APR of 8.9%. On average, the cost of Britelite double glazing windows is as follows:

Type of windowEstimated price

What we think

Britelite’s prices are transparent and always include VAT and fitting in every quote. Its prices are also lower than many of its competitors, making this brand a great option for buyers on a budget. The company has received praise for its clear and straightforward sales tactics, with 95% of customers rating its products and services as good or very good. Unlike with most of its rivals, you can also create a quote online to get an estimated price for your new windows.

Read our full Britelite review

Best financing options: Britannia

Britannia double glazing windows green

Image credit: Britannia

  • Energy efficiency: A+ for double glazing
  • Available materials: uPVC and aluminium
  • Available styles: Casement, flush, French, heritage, sash and tilt and turn
  • Guarantee options: 10-years transferable guarantee

Britannia is a family-owned double glazing windows factory in operation since 1982. It offers a fully made-to-measure service, so you can always get the best fit for your windows and a range of stylish options that suit historical aesthetics. 

Britannia’s window styles include casement, flush, French, heritage, sash and tilt and turn, in uPVC and aluminium materials. The company has numerous showrooms and offers efficient and friendly service and installations. 

You can spread the cost of your new double glazing windows using a range of excellent financing options. Britannia offers interest-free flexible monthly payments (including buy now and pay later options), 25% deposit and 10-months 0% APR representative credit and low repayments in five to 10 years at 8.9% APR representative. 


Britannia’s double glazing windows are affordable and of great quality. When compared to other brands (such as Anglian and Safestyle), their uPVC range is the only one that is slightly more expensive, with windows costing between £250 and £500.

Type of windowEstimated price

What we think

Britannia has a solid reputation backed by over 40 years of excellent service. They stand out in two categories; firstly, they provide a number of stylish windows that can fit your heritage property perfectly. Secondly, they have an unmatched number of financing options, including buy now and pay later, 10-months’ 0% APR representative and five to 10 years’ 8.9% APR representative (both subject to affordability).

Read our full Britannia review

How to find the best double glazing windows company

Installing or replacing your windows is a big investment and can add a lot of value to your home, so it’s important to find the right company to install your double glazing windows. Poor manufacturing quality and inadequate fitting can lead to major problems such as damage to your home, so here are our tips for choosing the best installer for your project.

1. Look for experience

A company that has been in business for a long time will usually have more experience in providing quality products and services.

2. Read customer reviews

The best way to determine the quality of a company is to research the experience of other customers. If a company has a lot of negative feedback, it’s worth looking elsewhere. How they respond to negative reviews is also a key indicator of their quality.

3. Look for accreditations and accolades

It is recommended you choose an installer that is registered under the Fenestration Self Assessment Scheme (FENSA) and complies with building regulations, as this will save you the time and money of registering your installation with the relevant authorities. Other accreditations and accolades that are a good sign of quality include British Fenestration Rating Council (BFRC), Secured By Design (SBD) and BSI Kitemarks.

4. Understand the guarantees on offer

While all double glazing windows companies are required to offer a minimum 10-year guarantee, some installers go above and beyond that period. A general rule is the longer the warranty the better.

5. Set a budget

Research the cost of installing double glazing and come up with an estimate for your project so you know roughly what to expect. Gather quotes from several companies so you can compare prices and determine which one offers the best value for money and understand this may not always be the cheapest option if a more expensive quote includes a longer guarantee.


Double glazing windows can help make your home more energy efficient, quieter, warmer and more secure. Fortunately, there are many brands that do an excellent job at this – the question is which one suits your home needs better. If you’re looking for the cheapest double glazing windows, Britelite has high-quality yet affordable options. If you want to finance your installation, Britannia has excellent plans. Everest, on the other hand, provides the best guarantees, while Anglian has an impressive range of styles and materials. Lastly, Safestyle is the most eco-friendly of the five and an excellent option for energy efficiency.

Frequently asked questions about double glazing windows


We conducted in-depth research reviewing and comparing the best double glazing companies in the UK. We looked into several brands and products and inspected customer reviews, comparing energy efficiency, window frames and glass options, guarantee, installation and price. Our analysis helped us identify the top double glazing companies available in the UK. The weight of the factors we analysed is as follows:

  • Design (20%)
  • Durability (20%)
  • Efficiency (25%)
  • Performance (25%)
  • Guarantee (10%)

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