I have a general code question regarding when a wall is considered interior and when it is considered exterior, as our team has looked for clear language in the NYS energy code as well as the ASHRAE 90.1-2007 standard, and we're unsure how to proceed with our energy model and verification strategy for EA credits.

Is a butting wall adjacent to another building, which is structurally independent, is considered an interior or exterior wall? Our understanding is that the adjacent wall should be considered an exterior wall since the building next to it can be demolished or come down. We understand that the adjacent wall isn't exposed to the outside enviroment but are still looking for a clear definition of an exterior wall. Is an exterior wall defined as any wall which will be exposed to the outside environment? Or is it defined as in ASHRAE "the elements of a building that separate conditioned spaces from the exterior", which would mean that the adjacent wall must be considered an interior wall?