Greenline House

Consumers, specifiers and legislators are increasingly focusing on the energy efficiency of building products. To respond to the challenge of raised expectations, the British Fenestration Rating Council (BFRC), in conjunction with the UK glazing industry and European partners has designed a window rating system to meet this need for simple and accurate information.

The BFRC provides third party certification for the total thermal performance of windows using a ‘fair, accurate and credible’ assessment scheme. Windows are rated using the familiar A to G scale on the basis of their total energy efficiency, where an A-rated window is more energy efficient than a G-rated window. Consumers and specifiers can quickly and easily choose the most suitable window for their needs, government inspectors and agencies can quickly and easily see if the window meets the legal requirements and energy agencies can see if the window meets their criteria for support.

The Window Energy rating assesses the whole window energy performance and covers the frame material, the frame design, the glass type and all the other components that make up the window. The rating is carried out by computer simulation and gives a single number that can be used to compare the energy performance of a window simply and quickly.

Window Energy Ratings (WERs):
  • allow consumers to rapidly compare the energy efficiency of competing products
  • allow specifiers to select windows based on a validated performance figure.
  • allow legislators and others to ensure that fitted windows meet the legal requirements.
  • allow energy agencies to direct support to energy efficient products.
  • provide a method to link thermal window performance to other thermal assessment systems.

Kömmerling window systems are capable of achieving ‘A’ to ‘C’ ratings depending upon window configuration and glass type and we now have our own in-house assessors. Please contact the Kömmerling technical department for further information.

'U' Values

'U' values are now also part of the latest Building Regulations which come into effect on 1st October 2010, where it is stated that any installed window must be a 'C' rating under the WERs or have a 'U' value of 1.6. 'U' values are widely used across Europe as a means to assess the thermal performance of building products and this includes the UK new build and refurbishment markets.

Kommerling has a wide range of products that can achieve 'U' values to meet any specification including Passivhaus and that includes our impressive 88 Plus system and a number of aluminium/pvc composite systems.