Window Energy Rating (WER)

Kitemark Scheme for Window Energy Rating (WER)

The Kitemark scheme for Window Energy Rating (WER) is based on the approved document L1B of the Building Regulations which comes into force on 1st October 2010. This stipulates that all replacement windows must have:

  • A Window Energy Rating (WER) of at least band C or
  • A declared U value of 1.6 W/m²K

To comply with the installation requirements for replacement windows after October fabricators must provide evidence of energy efficiency.

Our Kitemark scheme for Window Energy Rating provides a quality assured process and supporting audit trail from simulation of the WER through to installation and is therefore accepted by Building Control Bodies.

The WER Kitemark label can be used on the product down the supply chain ensuring that retailers and installers can use Kitemark Window Energy Rating certified windows.


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Window Energy Rating

Kitemark Scheme for Window Energy Rating (WER)

BSI WER Brochure

Tel: +44 (0)845 0809 000


Window Energy Rating

 Window Energy Rating