Sandwiching expanded polystyrene between two layers of OSB, the maker says its SIPs offer a 55% higher whole-wall efficiency than traditional 2x6, R-19 construction. By creating a virtually airtight building envelope, the panels’ energy efficiency can lower homeowners’ expenses up to 60% and reduce necessary HVAC equipment size by as much as 40%, the maker says. 800.275.7086.