With energy code evolution, another compliance path has emerged for builders to choose: the Energy Rating Index performance path found in IECC R406. This path emerged in the 2015 IECC and has further developed in the later codes.
The Energy Rating Index (ERI) was based on the proprietary HERS Index(TM) owned and developed by RESNET. RESNET also developed ANSI/RESNET/ICC Standards 301 and 380 which are referenced in the 2018 and later energy codes.
However, during the code development cycle there were additional requirements for the ERI that are not found in the ANSI standard and those requirements change the Index numbers dramatically. Those changes are not reflected in the HERS Index(TM), which can cause tons of confusion between code officials, raters, and builders as they work through ensuring homes comply with the current building codes.
Presenter: Brett Dillon, CEO The Dillon Group