Which of the following plastic is commonly used for window frames, gutters and drain pipes?

The story behind the answer

Polyvinylchloride (PVC) is ideal for window frames, gutters, and drain pipes because it’s rigid, durable, weather- and chemical-resistant, and low maintenance. In its unplasticized form (uPVC), it maintains high stiffness and dimensional stability, making it perfect for extruded profiles that won’t warp outdoors. Its chlorine content also gives it inherent flame resistance, and additives can improve UV stability—key for long-term outdoor use.

By contrast, polyethylene (PE) and polypropylene (PP) are more flexible and commonly used in packaging and containers, while polystyrene (PS) is brittle and often used as foam insulation. Memory tip: “P for Plumbing = PVC,” and “V for Vinyl in Visible windows.” PVC’s combination of strength, weatherability, and affordability explains its dominance in building applications.