The relative energy efficiency of windows can now be compared under the Window Energy Rating scheme (WER). This scheme uses labels similar to those seen on fridges and washing machines, displaying a scale from A to G with A being the most energy efficient.

For a given window, simply specifying PLANITHERM TOTAL+ can improve the WER by more than 13 kWh/m2/year compared to traditionally glazed products.

That is equivalent to more than a band improvement on the A-G scale, making it the most energy efficient window glass available.