Floors: Above Unconditioned Basement, Vented Crawlspace, Cantilevered Floors, and Floors above Garage, Code Compliance Brief Overview New language in the 2015 IECC allows different installation of insulation in floors over unconditioned spaces.
Ducts in Interstitial Floor Framing Description Guide for designing and installing interior ducts in an interstitial floor cavity in new and existing homes.