What is U Value?

A measure of how effective glass (and window) is in preventing heat escaping from the inside to the outside of a building. The lower the U Value, the greater resistance the glass has to heat flow and therefore the better insulator it is.  U Value is measured in W/m2k.

For example, 4mm VFloat™ Clear glass has a U Value of 5.9, whilst ComfortPlus™ has a U Value of 3.6. So ComfortPlus™ is a better insulating product than 4mm VFloat™ Clear glass.