Help with spray foam code – prescriptive vs. performance

Hi all, Thanks for reading. We are building a home in climate zone 4; Nashville, TN The spray foam quote on the exterior walls only calls for 4 inches of… Hi all, Thanks for reading. We are building a home in climate zone 4; Nashville, TN The spray foam quote on the exterior walls only calls for 4 inches of…Read MoreGreenBuildingAdvisor