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Best double glazing companies

Double glazing companies rated

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Put us to the test

Our Test Labs compare features and prices on a range of products. Try Which? to unlock our reviews. You'll instantly be able to compare our test scores, so you can make sure you don't get stuck with a Don't Buy.

Our survey of double glazing customers reveals how well-known firms Anglian, Everest and Safestyle compare with each other and local independents.

We've asked more than 2,000 double glazing customers to rate the company they used, including big brands Anglian, Everest and Safestyle, as well as local independent companies and traders. Read on to find out the best and worst double glazing firms.

Our unique research reveals what double glazing companies' customers think of them, and the results may surprise you. There is a big different between the top and bottom-rated double glazing companies - 30 percentage points, in fact. The top rating received a customer score of 86%, and the lowest is on just 56%. 

Our results also give each company, Anglian, Everest, Safestyle and independents, ratings for a number of important factors. This includes customer service, quality of products and installation, knowledge of staff, and mess made during the installation. You can use the results of our research to pick the best firm to install your double glazing.

Which? members can log in now to unlock all our customer ratings, plus our expert analysis of the results - which also reveals the firm that caused the most problems for its customers. 

If you're not yet a member, you can unlock our results with a £1 Which? trial. You'll also get access to all our online reviews and research, including our expert guide to double glazing prices.

Best double glazing companies

Sales ratings
  Knowledge of staff Clarity of documents Customer service Quality of products Value for money Customer score
Installation ratings
  Installers keeping to arranged times Knowledge and helpfulness of installers How well the installers communicated Mess during and after installation Quality of installation After sales support

Table notes: Customer score combines overall satisfaction and likelihood to recommend. Independents includes local double glazing companies, independent builders and independent joiners.

Sample sizes: Independents (1,526), Anglian (109), Everest (92) Safestyle (81). Survey conducted in August 2016.

Double glazing companies compared

To help you determine which double glazing company is best, we asked customers to state how satisfied they are with a company, and whether they would recommend it to a friend, which combines to give an overall customer score for each company. 

We also asked them to rate a number of aspects of the sales and installation process - such as clarity of documentation (for example, the contract), how well the installers communicated and after sales support - from very poor to excellent.

You can log in now or sign up for a £1 Which? trial to unlock our results above, and see our 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 on Anglian, Everest and Safestyle

Common double glazing problems

No matter how good a company is, there can sometimes still be problems. To help you avoid potential pitfalls, we asked double glazing customers what issues they came across when they got double glazing. Some 70% didn't have any problems at all, which is encouraging. But that means 30% did.

The most common problem was that the installation took longer than planned (12% had this happen to them), so it's worth building in extra time in case this happens. Other common problems were:

  • 14% Installers caused damage to the interior/fixtures and fittings
  • 14% Windows didn’t fit as well as they should
  • 14% Work started later than planned
  • 13% Scratched glass
  • 12% Wrong positioning of panes/parts
  • 11% Some fittings (e.g. screw head covers) were not installed
  • 10% Scratched/damaged frame(s)
  • 9% Installers caused damage to the property exterior
  • 9% Installers left a mess
  • 4% Installers did not leave keys for all the windows

Problems by brand

Log in or sign up for a trial to find out which companies customers had the most problems with.

Signing up or logging in will also unlock our page on double glazing sales and quotes, which includes tips from double glazing customers and experts on how to side-step sales tactics. 

You'll also be able to access our guide to typical double glazing prices, where you'll see the average prices for different types of doors and windows. You can use this information to help make sure you get a good price for your windows.

How Which? rates double glazing companies

In August 2016, we asked 2,239 Which? members about their experiences with the company they bought double glazed windows and/or doors from, and had them installed by, in the last five years. 

Overall customer scores are based on how satisfied customers were with the brand, and how likely they were to recommend it to a friend. We also asked them to rate the companies for a number of factors crucial to the sales and installation of the double glazing.