2009 Washington State Energy Code (WSEC)


On January 1, the 2009 Washington State Energy Code (WSEC) became effective. Originally scheduled to take effect July 1, 2010, a lawsuit filed in May and a request to delay by the Governor and others in June led the State Building Code Council (SBCC) to temporarily delay the implementation date on June 11. After public hearings in September, the SBCC voted on October 15 to set the implementation date of January 1, 2011.

The 2009 WSEC is expected to be substantially more stringent than the 2009 IECC.

Multiple resources on the 2009 WSEC residential provisions are available through the Washington State University Energy Extension Program, including:

  • Significant changes from the residential provisions of the 2006 WSEC
  • Incremental first cost analyses for residential and non-residential buildings. The residential report shows that in a gas heated house of average size house the cost of applying the 2009 WSEC is about $1.00 per sq. ft. The return on investment to the homeowner occurs around Year 3 of home ownership
  • An extensive 2011 training schedule, including courses on energy code compliance, duct testing, ENERGY STAR/PTCS/HERS rater certification, and industrial equipment.

More Information: 2009 WSEC | State Building Code Council


Back to Washington Code Status Page

Based on: 
Date Passed: 
Friday, November 20, 2009
Date Effective: 
Saturday, January 1, 2011
Notes & Exceptions: 

The 2009 WSEC is expected to be substantially more stringent than the 2009 IECC.

You may login with either your assigned username or your e-mail address.
The password field is case sensitive.