What’s Changed in the IECC for 2015 – Part Two

by Ryan VanArsdale

In our last blog post, we talked about the changes in the IECC from the 2012 to the 2015 version.  While we covered the changes in general, we want to spend a little time with the most notable change to the new IECC, to clarify what it means for you. A new performance path has been approved, and can be found in Section R406, Energy Rating Index Compliance Alternative. This new option is based on an Energy Rating Index. This section lays out required ERI scores, building envelope levels and approved third party participation.

To begin with, the basis of performance has been energy costs – until now. The 2015 IECC requires an ERI (Energy Rating Index) of between 51 and 55, depending on the climate zone. The following table shows what ERI each climate zone must achieve.

Climate Zone	1	2	3	4	5	6	7	8
ERI	52	52	51	54	55	54	53	53

Also, the following provisions should be noted in Chapter 4 - Energy Efficiency:

1. Testing for building envelope air leakage requires that all testing be performed under ASTM E779 or ASTM E1827.
2. Building envelope stringency levels must be at least equal to the 2009 IECC levels.
3. Verification of compliance must be completed by an approved third – party agency.

If you missed our previous blog post, be sure to read our overview of the changes to the IECC at ‘What’s Changed in the IECC for 2015 – Part One.'

For more help understanding and complying with the 2015 IECC, contact NTA. Our knowledgeable account managers and engineers can help you ensure your project is ready for the new 2015 IECC.