Window Energy Ratings
Document ‘L’ Compliance and WERs
Profile 22 delivers more opportunity to help fabricators and installers maximise the sales potential from window energy ratings and U-values with a complete package of support to help you achieve full compliance with the latest legislation – from technical assistance in achieving energy-rated windows, through to sales support that helps you sell the benefits on to the trade, retail and commercial sectors.
All Profile 22 customers benefit from unique tools to help them achieve certification, such as our unique U-Comply Self-Help Calculator, which generates accurate, verified window and door specifications for U-values and window energy ratings.
What is a Window Energy Rating (WER)?
Window Energy Ratings provide a benchmark for comparing the energy efficiency of different window systems. The rating is a single number that measures a window’s overall energy performance. Building regulations currently stipulate a minimum requirement of ‘C’ (or a U-value of 1.6 W/m2K) for all window installations.
It is calculated by measuring the energy flow through a standard window (1.23m x 1.48m) and takes three variable factors into account:
- The heat transmitted into the building through the glass from the sun (solar gain)
- The heat loss from the building through thermal transmittance of the window components (expressed as the whole window U-value)
- The heat loss resulting from air leakage through the weather seals
The energy efficiency of a window is shown by the widely-recognised Window Energy Rating.
For more details on energy efficiency and how to achieve the best possible energy rating contact us.