Sun Trade Window Energy Ratings

Window Energy Ratings

Our Commitment

We have always had a commitment to our customers and the environment, year after year we continue to re-evaluate the market and assess areas where we can see potential improvements. Further to the changes in the Building Regulations we have increased our range of WER certified windows even further offering greater choice and even more benefit.


Housing is one of the major sources of energy use, and one of the main areas of energy loss is via the glazing. Windows are in place for a long time and efficiency gains achieved by fitting high performance windows are effective for the life of the product. By increasing the energy efficiency of glazed areas this will significantly reduce fuel bills, improve comfort and reduce greenhouse gas emissions for the life of the window installation.

What is the Window Energy Rating

The British Fenestration Rating Council (BFRC) is an independent, government-backed initiative set up to enhance the energy performance of buildings. BFRC in conjunction with the U.K. glazing industry and European partners has developed a Window Energy Rating to assess the energy performance of domestic windows. For consumer purposes, the WER Rating value is converted on a A* to E scale, which is known to the public from electrical products such as fridges and washing machines.

Building Regulations

The WER Rating for windows is now included in the Building Regulation Part L with effect from October 2010. Beside the existing target U-Values for replacement windows, compliance to Part L1B can be shown using certain Window Energy Ratings. The standard for replacement windows in an existing dwelling should be an energy rating of ‘C’ or better with the standard for new windows in extensions also being a ‘C’ rating or better. For new dwellings the compliance with Part L is proven via a Target CO2 Emission Rate, which needs to be met, without specific WER requirements for the windows.

Achievable WER Ratings

The Solar Gain, the Thermal Transmittance and the Air Leakage all influence the WER rating. By combining industry leading components with the very latest in glazing options we are able to produce A*, A+, A, B & C rated windows to match every style of home. If you require more information on our A*, A+, A, B & C rated window options please feel free to get in touch today.

Sun Trade Window Energy Ratings