Westlake is a vertically integrated manufacturer operating across two segments: building and infrastructure products, and commodity chemicals. The Housing and Infrastructure Products (HIP) segment makes PVC siding, trim, mouldings, architectural stone veneer, roofing tiles, windows, PVC pipe and fittings, and specialty polymer compounds. These products are sold to homebuilders, distributors, and municipal contractors, with end use roughly split between new residential construction and repair and remodel. The Performance and Essential Materials (PEM) segment produces commodity and specialty chemicals including PVC resin, polyethylene, chlorine, caustic soda, and epoxy resins, sold to downstream fabricators and industrial customers globally. Westlake's core economic logic is vertical integration: the company produces ethylene and chlorine internally, combines them into VCM, converts VCM into PVC resin, and feeds that resin directly into HIP to make finished building products. This chain lets Westlake capture margin at multiple steps and insulates HIP from external PVC supply disruptions. HIP generates higher and more stable margins, while PEM is cyclical and heavily exposed to global supply-demand spreads. Westlake's PEM competitive advantage rests on low-cost ethane-based feedstock on the U.S. Gulf Coast. Growth strategy centers on HIP, targeting organic share gains with national homebuilders, product innovation in PVCO pipe, and bolt-on acquisitions, while PEM is being restructured through plant closures, reliability improvements, and cost reductions.