Many states currently at the IECC 2009 code are bypassing IECC 2012 altogether and adopting IECC 2015. If your state’s current code is based on the older IECC 2009 and ASHRAE 90.1-2007 Standard, you will see more significant envelope changes. An Overview: IECC 2015 and ASHRAE 90.1-2013įirst, it’s important to know that I base the most recent code cycle changes on comparisons of the IECC 2012 code and the ASHRAE 90.1-2010 Standard. That blog breaks down a lot of the background information pertinent to understanding the current code landscape, such as the difference between IECC and ASHRAE. Check the status of your state energy code at .Īlso, before you continue reading about the latest code cycle, you might want to revisit my primer on ensuring commercial code compliance in a post I wrote back in 2014.

So, theoretically, your state could switch in the next few months or in a few years. Remember that each state is in a code cycle, which lasts two to three years. For some states the new code has already gone into effect as of January 1, 2017, but the exact timing of implementation depends on each state. The next commercial energy code cycle for most states is the IECC 2015 code and ASHRAE 90.1-2013 alternative path. The latest code cycle requires higher insulation values and an air barrier in the thermal envelope.