Our survey of 3,467 double glazing customers reveals ratings for brands including Everest, Anglian and Safestyle, as well as what customers think of independent double glaziers, so you can find out which firm is best - and how Everest shapes up against the competition.
The results of our survey reveal vast differences between companies. Customers raved about our top-scorer, which achieved an overall customer score of 81%. In contrast, the bottom-rated double glazing brand picked up just 52% - almost 30 percentage points less.
Everest customers most commonly told us they chose the firm because it had a good reputation, had windows or doors they liked or they had bought from it before. So does Everest live up to customers' expectations? Keep reading to find out.
The table below shows how Everest's customers rated it across 15 areas of the buying and installation process.
These cover sales, purchase, installation, after-sales and how well the product lasted, and include staff knowledge, the quality of products and installation, clarity of documents - such as the contract - and value for money.
Sales and purchase
How well the double glazing lasted
We asked Everest's customers to tell us how satisfied they are with the brand and whether they would recommend it. We then use this data to calculate an overall customer score.
We also asked them to rate, on a seven-point scale from very poor to excellent, a number of aspects of the process. We analyse the responses to produce our star ratings. You can use these ratings to help you understand which elements the companies in our survey succeed on, and where they fall down.
Flick through the images below to see some examples of the types of double-glazed windows and doors Everest provides, and read on below to learn more about its services.
England, Scotland and Wales, but not Northern Ireland.
Everest sells casement and bay windows in uPVC, timber and aluminum; sash in uPVC and timber; uPVC flush windows; timber dual-turn, and uPVC tilt-and-turn in a range of colours, including woodgrain effect.
The uPVC windows are also available in a range of colours and woodgrain effect. It offers paint or stain finishes on timber windows to highlight the grain. Everest's windows and doors have its GrabLock, developed with Yale.
Everest sells aluminium bi-fold doors in a range of colours, aluminium and uPVC patio doors, and French doors in timber, aluminum and composite.
It also does garage, porch and composite, timber, uPVC and aluminium front and back doors, most partially glazed.
A+ rating as standard for uPVC casement windows. Triple glazing is A++. It doesn't state the energy ratings for other double glazing on its website.
Everest offers triple glazing and secondary glazing options in addition to double glazing. It also offers acoustic glass to help to reduce noise.
Everst has a 10-year guarantee on most parts and materials in its products, but a 20-year guarantee for its uPVC Exclusives windows and doors range. Some have a lifetime guarantee, which covers condensation and fogging between uPVC panes, but you have to pay extra for this.
Everest is accredited by Fenestration Self-Assessment Scheme and Glass and Glazing Federation, which means Everest installers can self-certify that the double glazing is compliant with building regulations. This saves you from having to contact your local council's building control department yourself.
Everest also does flat roots, roofline/rooftrim (such as guttering, bargeboards, cladding etc), driveways, artificial grass, Yale smart locks and security alarm systems.