The Window Energy Rating (WER) scheme is a consumer-friendly method of demonstrating the overall energy performance of a window.

A WER takes into account heat loss from the window (whole window ‘U-value’ or ‘Uw’), and air leakage (‘L value’) together with passive heat gained from the sun that passes through the glass into the room (solar gain or ‘g-value’).

These gains and losses are applied to a standard equation by a trained assessor (known as a ‘simulator’) to generate an overall Energy Index value. This is translated into a rating between ‘A’ (best) and ‘G’ (worst). This rating can be displayed on the window in a similar way to white goods to demonstrate its overall energy performance.

The WER scheme is administered by the British Fenestration Rating Council.

What WER do I need?

Currently, an installation can comply with the UK Building Regulations by having an ‘E’ WER. From October 2010, a ‘C’ WER will be required as a minimum for domestic home improvement installations in the UK, including Scotland (the WER scheme is not applicable for new-build installations, albeit house developers are beginning to request it).  However, an ‘A’ rated window can be a powerful marketing tool when selling to the end consumer.

How do I get Window Energy Ratings for my windows?

Below is a simplified flow chart showing how you can achieve Window Energy Ratings. By signing up with Solaglas on the WER Ready scheme, we will provide you with all the information you need, expert and independent help every step of the way, comprehensive financial support and the market’s leading sealed unit
(SGG EcoClear®+) to assist you in getting the very best ratings:

There are also other benefits to signing up with Solaglas, find out here

The WER label

Once your windows have been WER accredited, you can affix coloured rating labels to your finished windows or include one in your sales paperwork. But what does the information on the label mean? View our illustration which identifies the key elements and for further information on WER jargon see our WER Glossary.