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3 December 2020

Double glazing companies rated

Our research reveals how well-known firms including Everest, Safestyle and Anglian compare when rated by hundreds of double glazing customers.
Houses with double glazed windows 478462
SI
Sarah Ingrams

We've asked thousands of double glazing customers to rate the company they used, including brands Anglian, Everest and Safestyle, as well as independent traders.

The answers, from more than 3,000 double glazing customers who bought double glazing in the past 10 years, mean we've rated more double glazing brands than ever before. The results reveal big differences between brands.

Nearly 30 percentage points separate the top and bottom overall scores. Some glazing firms achieved a full five stars for customer service, while one company gained just two stars from customers for value for money and after-sales support. 

Our results rate each double glazing company across lots of factors, including customer service, quality of products and installation, knowledge and helpfulness of staff, and how much mess they made during the installation.

Below, we reveal how double glazing companies fared on everything from customer service to value for money - according to their customers. Ready to buy? Find out how much double glazing costs.

Which double glazing company is best?

Only logged-in Which? members can access the customer ratings in the table below. If you're not yet a member,  join Which?  to unlock our results and see analysis on which areas the companies are succeeding in, and how they're failing their customers. This will also give you access to the full reviews of Anglian double glazing, Everest double glazing, Safestyle double glazing and more.

Big differences exist between the highest and lowest ratings and customer scores achieved by companies in our survey. On customer service, one brand only gained three stars, based on its customers' feedback, while others achieved five stars.

The table gives a snapshot of the areas on which we've rated double glazing firms, based on the feedback of their customers. Our full ratings cover sales and purchase, delivery, installation, after-sales support and how well the windows or doors stand up to the test of time.

Double glazing companies rated by their customers
Double glazing firm Knowledge of salesperson Customer service Delivery speed Quality of products Installation quality Value for money Customer score
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81%
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78%
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73%
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68%
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65%
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63%
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60%
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52%

Which? double glazing company reviews

Our ratings include customer feedback across all aspects of buying and owing double glazing – from sales and purchase, to delivery, installation and how well the windows or doors lasted.

The results for each company are based on our survey of 3,467 people in August 2020 who bought double glazing for their home in the last 10 years. 

Customer scores are based on a combination of how satisfied customers of the brand say they are, and how likely they are to recommend it, if asked.

We also ask customers to rate more than 10 other aspects including the choice of products, clarity of documents (e.g. the contract), how well the installers communicated and how well the double glazed windows or doors have lasted. Customers rate them on a scale from very poor to excellent which we translate into a star rating.

Besides rating eight of the biggest double glazing brands, we have created a dedicated advice guide for buying from an independent double glazing firm as 45% of people in our survey bought from a local or independent double glazier.

If you're ready to buy now, head to our page on double glazing sales and quotes for more details on what your new windows or doors should cost.

Anglian, Everest and Safestyle double glazing compared

The three biggest double glazing chains have been included in our annual survey for several years. This year, one of them scored lowest out of the eight firms in our survey and was the only firm to get two out of five stars on some aspects of its service.

Visit our dedicated pages on Anglian, Everest and Safestyle to find out which firm it was, plus more about how the firms compare and the services they offer.

Britelite double glazing

Britelite is included in our double glazing survey for the first time this year. It has more than 45 years' experience of fitting windows, doors and conservatories.

The firm says it has always aimed to supply the best product at the keenest price and serves customers in Kent, Sussex, Essex, Surrey and London.

Which? members can log in to find out what customers thought of Britelite in our survey. If you’re not a member, you can join Which? to see our exclusive ratings.

Britelite windows, doors and guarantee

Britelite installs windows, doors and conservatories in Kent, Sussex, Essex, Surrey and London.

All of its products have a 10-year guarantee.

Britelite is a Which? Trusted Trader, which means it has passed rigorous checks and vetting. Use our free service to find a  reputable, reliable double glazing firm near you.

Coral Windows

Which? members can log in to find out what customers thought of Coral Windows in our survey. If you’re not a member, you can join Which? to see our exclusive ratings.

Coral Windows was included in our double glazing survey for the first time. It says it prides itself on quality and excellent customer service. But how did it fare in our survey?

Serving households in Yorkshire since 1990, Coral Windows has three showrooms and develops, designs and manufactures all of its doors, windows and conservatories in Bradford.

Unusually, it doesn't take deposits; customers pay in full when their project is complete.

Coral Windows products and guarantee

Coral windows sells double-glazed windows, doors, conservatories and orangeries, all of which it makes at its manufacturing plant and head office in Bradford. 

Its uPVC frames have a 15-year guarantee, and sealed units have a 10-year guarantee.

Coral Windows is a Which? Trusted Trader, which means it has passed rigorous checks and vetting. Use our free service to find a reputable, reliable double glazing firm near you. 

CR Smith double glazing

CR Smith says that customers will feel good about their choice for years to come. Which? members can log in to find out what customers thought of the brand in our survey. If you’re not a member, you can join Which? to see our exclusive ratings.

This is the first time that CR Smith has had a rating in our double glazing survey, but how did it get on?

The Dunfermline-based firm has been fitting double glazing for more than 40 years, although the name has been around for over 100 years. It has its own manufacturing plant and employs more than 400 people.

CR Smith windows, doors and guarantee

CR Smith sells a range of double-glazed windows, including sliding sash, casement, tilt-and-turn and reversible styles. It also offers a range of front doors and patio doors, conservatories, orangeries and sunrooms, and will both build and decorate them.

All its Lorimer windows have 10-year guarantees for parts and workmanship. It also promises to replace any window or door fitted in brick surrounds if it fails when an intruder breaks in (unless they break the glass).

It has a 24-hour, 365-day emergency call-out service to help if you have an urgent problem, such as a security risk, or you’re locked out.

Crystal Windows and Doors

Which? members can log in to find out how customers rated Crystal in our survey. If you’re not a member, you can join Which? to see our exclusive ratings.

Crystal Windows and Doors was rated in our double glazing survey for the first time this year. So how did it compare with other big brands?

Based in Essex, it installs a range of windows and doors for homes and garages and also does roofline work, including soffits and fascias.

Crystal Windows has been trading since 1995 and makes all of its products in its Romford factory. It says that it’s focused on continuous improvement to products and services. 

Crystal Windows and Doors products and guarantee

Crystal Windows and Doors sells a range of double-glazed windows, including sliding sash, casement, tilt and turn and reversible styles. It also offers a range of front doors and patio doors, as well as garage doors, roof services, driveways and spray-foam insulation.

It offers a 10-year guarantee, which it says is its customers’ favourite feature. Crystal says that this means if you have any problems with its products, its dedicated team will help sort things out.

First Home Improvements

First Home Improvements says it offers a first-class service to help customers choose the best double glazing. Which? members can log in to find out if First Home Improvements lives up to its promise, according to customers in our survey. If you’re not a member, you can join Which? to see our exclusive ratings.

First Home Improvements claims to be one of the longest-established double glazing companies but this is the first time it has been included in our double glazing customer survey. Find out how it fared.

It supplies double glazing to homes in the east of England, from Sussex to Lincolnshire, and makes its products in Norwich.

First Home Improvements products and guarantee

First Home Improvements installs windows, doors, conservatories, porches, garages and does roofline work.

It offers a 10-year warranty on all products, and 12 years on windows.

Independent firms and double glazing near me

A large proportion of the double glazing owners we spoke to (45%) used an independent company. This includes double glazing firms local to them and independent companies not in their area.

It may also include local builders and joiners, who you're more likely to use if you're having new windows or doors as part of a home renovation, such as a new extension.

Find out why customers chose independent double glazing companies and what they thought of them in comparison with bigger brands.

Find a reputable double glazing company near you by using Which? Trusted Traders

All traders who use our logo have been through rigorous background checks, done by ex-Trading Standards assessors. The traders must also agree to follow our code of conduct and are checked on an ongoing basis. 

Don't get overcharged for your new windows. We've crunched the numbers to find out the average cost for various sizes and types of double-glazed windows and doors. See the latest double glazing prices. 

Common double glazing problems

No matter how good a company is, problems can arise. To help you avoid potential pitfalls, we asked double glazing customers what issues they came across with the purchase, delivery and installation of their double glazing.

Reassuringly, 73% of our survey respondents said they had no problems. 

Post-installation problems were the most commonly reported, followed by installation problems, delivery problems and problems when buying.

While 18% told us about post-installation issues, just 2% reported a problem with buying their double glazing.

The most common post-installation problems include doors and windows becoming difficult to open or close, and windows or doors sagging so that they don't fit as well. 

Visit our page on double glazing repairs and maintenance for tips on how to fix window problems.

The most common issues with installing double glazing were:
  • windows not fitting as well as they should
  • installation taking longer than planned
  • wrong positioning of panes or parts.

To head off potential problems early, make sure you have a clear idea of what you want, that you understand what you're buying, you get clear and detailed information and that you don't feel under pressure to make a purchase quickly. 

If you're currently having difficulties with your double glazing company, our page on your rights when buying double glazing talks you through the steps you need to take.

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