Basement – calculating interior insulation R-Value with exterior foundation insulation

Newer home (less than 5 years old) on boarder of zones 6A & 7A. Has existing exterior foundation insulation of R10 that is a ridged fiberglass. Full basement (i.e. all… Newer home (less than 5 years old) on boarder of zones 6A & 7A. Has existing exterior foundation insulation of R10 that is a ridged fiberglass. Full basement (i.e. all…Read MoreGreenBuildingAdvisor