Double stud wall wood framing is not specifically addressed in the International Residential Code (IRC) or International Energy Conservation Code (IECC); it is neither encouraged nor discouraged. Recommendations of where the vapor retarder and air barrier should be placed, based on research and testing are further defined in this Code Compliance Brief.
An entirely new section in the 2015 IECC/IRC regarding fuel-burning appliances basically requires the appliance to be isolated from the building thermal envelope, located either outside or within a separate room if the fuel-burning appliance is supplied by open combustion air ducts. This brief provides an overview of the requirements and further details of approving the actual "room".
This brief discusses the provisions in the 2015 International Energy Conservation Code (IECC) and International Residential Code (IRC) related to evaporative cooling.