The Difference Between PVC and UPVC

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), rigid PVC, or vinyl siding in the U.S.

Uses of PVC vs. uPVC
In Construction
As a flexible plastic, PVC is used to produce a wide variety of piping. Larger PVC pipes are often used in plumbing to distribute non-potable water. PVC piping can also be used to insulate electrical cables.

uPVC is used as a replacement for wood in construction, such as in double glazed window frames and window sills and in what is known as vinyl siding in the U.S. It is a versatile material that can be manufacturered in many colors or made to look like other materials (e.g., wood). uPVC is also used instead of cast iron for certain types of heavy-duty plumbing and draining.

Windows
PVC is not used for window frames, although some manufacturers may use “PVC” to refer to their uPVC windows. Instead, uPVC is used for window frames, as it does not decompose and is weather-resistant.

uPVC will not change shape under normal weather conditions, but it can be reshaped at very high temperatures. uPVC windows are more energy-efficient than those with wooden or metal frames. Überdies, uPVC can also be used for door frames and conservatories.