If your UPVC window won’t open there may be a few causes. The simplest of them to to fix will be a faulty window handle. At the other end of the spectrum is a window jammed shut because the mechanism has broken.
With the correct tools a jammed window can be opened and the mechanism replaced. We carry stock for most types of window mechanism.
Even a layman can see why the mechanism in the picture below wasn’t working. This make and model of espag (espagnolette) gearbox is one of the more common ones we come across.