Terminology made easy
A window's insulation value is becoming increasingly important, particularly in light of the ever-more stringent demands. By insulation value, we mean the U-value (heat transmission coefficient), which records how much heat the element loses per m2 .
In a nutshell, this means:
The lower the U-value, the better the window is at retaining heat.
Ug = Value for the glass (g = glass)
Uf = Value for the frame (f = frame)
Uw = Value for the entire window (w = window)
There are lots of different types of window. They differ depending on their opening mechanism or the number of sashes, e.g. single or multi-sash windows, sliding windows, etc.
When it comes to selecting a uPVC window, the opening mechanism can play a decisive role if you're looking to make the most of your space or want to let in as much as air as possible.