Which window frames are the best: Fiberglass, PVC or Fiberglass hybrid uPVC?
...uPVC as they are both made of polyvinyl chloride which is a very toxic and dangerous substance. PVC window frames are also more susceptible to warping with extreme temperature fluctuations, so for colder climates uPvC may be better of the two. UPVC has no plasticizers in it so it is more rigid.
Our preference for windo...