PDFWAC 51-52-004
Conflict between International Mechanical Code and State Energy Code chapter 51-11C WAC.
In the case of conflict between the duct sealing or insulation requirements of Section 603 or Section 604 of this code and the duct sealing or insulation requirements of chapter 51-11C WAC, the Washington State Energy Code, or where applicable, a local jurisdiction's energy code, the provisions of such energy codes shall govern.