For HERS® Raters and RFIs, understanding the differences between the HERS® Index and the International Energy Conservation Code (IECC)’s Energy Rating Index (ERI) is critical to educating builders and code officials on their important differences. The IECC’s ERI is a compliance pathway in the 2015, 2018, and 2021 versions of the IECC. The Home Energy Rating System (HERS) Index is a voluntary, national program used to rate the energy efficiency of homes. To date, there are over 2.9 million homes that have received a HERS® rating. Although both HERS® and the IECC’s ERI are largely based on the same American National Standard, ANSI/RESNET/ICC Standard 301, there are significant differences between these two programs. Under the 2015 IECC, ERI and HERS® were the same because there was no reference standard for calculating ERI scores. However, this changed under the 2018 IECC with the addition of ANSI/RESNET/ICC 301-2014 as the reference standard for calculating the ERI score and an amendment to R406.3 which changed the ventilation rate for the ERI reference home. The HERS® Index does not incorporate the IECC amendment. This can create a significant difference in scores between the HERS® Index and the IECC’s ERI. These two changes are just the tip of the iceberg when it comes to understanding the differences between HERS® and ERI. This webinar will clarify the differences between the IECC’s ERI scores and HERS® scores to assist state and local code officials, builders, and HERS® Raters/RFIs with understanding how each works. Register here.
