One of the biggest challenges to creating an energy efficient house is to reduce the air leakage as much as possible. While we have chosen to use ICF and SIP framing to greatly reduce the air leakage in the walls, and Nudura Ceiling for ceiling insulation, the gaps and interfaces need to be sealed as well in order to be air tight as possible, and the choice of the casement fiberglass windows.
We chose to spray foam insulate the weak points of the house; the ledger board area where the SIP interfaces to the ICF, the penetrations around the house to the outside, the pot light wire penetrations into the attic, and where the walls on the 2nd floor meet the ceiling.