UPVC stands for Unplasticized Polyvinyl Chloride and is also known as rigid PVC. The term Unplasticized means no additional plasticizing polymers are used in UPVC manufacturing process and hence is the most durable form of PVC. Regular PVC (polyvinyl chloride) is a common, strong but lightweight plastic used in construction. It is made softer and more flexible by the addition of plasticizers. If no plasticizers are added, it is known as uPVC (unplasticized polyvinyl chloride) or rigid PVC.