The 2012 Washington State Energy Code (WSEC) went into effect July 1, 2013.  This new WSEC is now based on the 2012 International Energy Conservation Code with State amendments.  For residential construction this means better air sealing of the exterior envelope, more efficient windows, tighter sealing of duct work, and more high-efficacy lighting fixtures, plus many other changes from the 2009 code. 

As part of the building air tightness requirements, the code now allows the local building official to require an approved third party to inspect all components of air barrier system and verify compliance.  Air leakage testing using the blower door method is also required after visual inspection of all sealing components.  Test reports must be provided to the code official.  Here again the local building official can require the testing be performed by an approved third party. 

Duct work, air handlers and furnaces are all required to be sealed for air leakage.  Similar to the 2009 WSEC, duct work is required to be leak tested by a qualified technician.  Allowable duct leakage thresholds are stricter in the current code.  Replacement of an existing furnace, air handling unit or air conditioning unit also triggers the duct testing requirement of the duct system connected to the new or replacement equipment.

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