UPVC windows and doors is Unplasticized polyvinyl chloride: is PVC windows and doors before plasticizers have been added to make the material flexible. It is made in the same way as PVC but without the plasticizers which makes it very strong and rigid, UPVC is most commonly used for window and door frames as an alternative to wood, UPVC is proven to offer excellent performance and durability, it is long lasting and requires very little maintenance making it the perfect material for your windows and doors.