The California Energy Commission (CEC) has recently revised its building energy standard, Title 24. As part of the revision of the energy code the CEC incorporated the air tightness testing protocols established in RESNET’s Chapter 8, “RESNET Standard for Performance Testing and Work Scope”. In a move to reduce energy costs, save consumers money, and increase comfort, the CEC on May 31 unanimously approved the revision of the state’s energy efficiency standards for new homes and commercial buildings. The Energy Commission’s 2013 Building Energy Efficiency Standards are 25 percent more efficient than the previous state standard for residential. The revised standard will take effect on January 1, 2014. This is the step to meeting the state’s commitment to net zero energy homes by 2020. Section RA3.8 of the revised Title 24 addresses field verification and diagnostic testing of building air leakage. The section states that “the purpose of this test procedure is to measure the air leakage rate through a building enclosure measured in cubic feet per minute at a 50 Pa pressure difference (CFM50). The measurement procedure described in this section is derived from Residential Energy Services Network’s (RESNET) Mortgage Industry National Home Energy Rating Standards.” I have attached a copy of the section of Title 24 addressing air leakage testing. This action by the California Energy Commission is another milestone is the movement to incorporate RESNET standards into energy codes. The RESNET Technical Committee is in the process of drafting a proposed ANSI standard on performance testing based upon Chapter 8. The 2012 version of the International Energy Conservation Code (IECC) requires performance testing of air tightness and duct leakage but not identifies the protocols for such testing. Incorporation of RESNET’s Chapter 8 into an ANSI standard poises the standard to be incorporated into the IECC.