Green Term Defined: Thermal Bridging
Thermal bridging is one of the biggest problems we have when trying to create a high performance home. You have to find an economical solution that does not create a bridge from inside to outside the home. A thermal bridge is where heat occurs across more conductive components in an otherwise well-insulated material, resulting in disproportionately significant heat loss.
Thermal Bridging can occur when using wood studs, steel studs, pre-engineered metal building, Insulated Concrete Forms, and even SIPS. The 2012 building code that is the basis for the Virginia Statewide Building Code has recognized this as an issue in creating energy-efficient buildings. You now have to either add additional insulation in roof structure, higher performing windows, or wrap your building in a insulation blanket such as rigid foam.
There are many problems with simply adding rigid foam on the outside of the wall system. The biggest being the potential for trapping moisture inside the wall system by creating a vapor barrier. A keen understanding of building science is needed or we are going to have buildings that have moisture in the walls which can lead to mold and rot.