Window Energy Ratings - A Concise Guide

Posted by | July 16, 2021

We're first to admit that the double glazing trade is full of jargon that can be confusing if you are trying to settle on the type of windows and doors that will be right for your home.

But some of those terms and ratings are useful in helping you evaluate the performance of a particular window. Because windows vary in type, quality and performance between manufacturers and companies, there are industry standards that can be used to robustly assess and rate windows so you can objectively compare them.

As a prospective double glazing customer, the key rating you need to be familiar with is the Window Energy Rating (WER) system. This rating system has been developed and delivered by the British Fenestration Rating Council (BFRC) a leading national and European body in the glazing industry. The WER system provides the industry standard for verifying and rating the energy performance of double and triple glazed windows.

The WER rating system provides letter-graded ratings for double glazed windows and doors. Their trusted rainbow rating confirms that double glazing products have been verified for performance by industry experts. The rating does not only covers the glass but the entire system including seals and frames, providing confidence that your new windows will perform as promised.

Let’s take a closer look at the first 3 ratings: A, B, and C.

  • A rating: Just like your exam grades at school. An A, A+, or A++ rating is the best you can get. Like fridges and freezers, A-rated windows are the most energy-efficient and should make the most impact on your household energy consumption and bills.
  • B rating: B rated windows still provide exemplary thermal efficiency, but do not match the performance of A-rated windows. B-rated windows are usually cheaper meaning that your up-front costs for new glazing are lower.
  • C rating: C rated windows have slightly less performance than the B rated windows and therefore are cheaper still. They may prove an accessible or affordable option if you are looking to upgrade your glazing on a budget.

These letters matter as building regulations specify a minimum performance for your new windows.

You may think you can save money by purchasing D, E or even F rated windows, but if you do, you will fall foul of building regulation. This is because, by law, replacement windows must have at least a C rating for energy efficiency or equivalent U-value.

We are ready to help you choose the best windows for your property and budget.

One of the most satisfying aspects of our trade is seeing just how much people can save by investing in the right windows. We are on hand to provide the advice and information that you need to pinpoint windows with the perfect design performance and price point for your home.

Contact us by phone or email to ask us anything about windows. We will be pleased to answer all questions and if you would like, our team will arrange a complimentary visit to measure your home for new windows, free of charge.