XPS is generally positioned as a premium insulation product. It is typically more expensive per board foot than:
- EPS (Expanded Polystyrene): Lower cost, but with lower R-value and moisture resistance.
- Fiberglass Batt: Significantly lower cost, but performance depends heavily on installation quality and it offers no inherent air/moisture barrier.
It is often cost-competitive or slightly more expensive than rigid polyisocyanurate (PIR) foam, depending on thickness and region. The true cost analysis must consider installed performance and lifetime value. XPS’s high R-value per inch, moisture resistance, and durability often lead to lower long-term energy costs, reduced risk of moisture problems, and less maintenance, justifying the higher initial investment, especially in demanding applications.
