Unlike most other building codes, the energy code has multiple compliance paths. When combined with the fact that the energy code is a relative newcomer to the code scene and often treated as less important than traditional life safety codes; it’s easy to see why there is confusion among builders and code officials. Prior to the 2015 International Energy Conservation Code (IECC), the energy code had three compliance paths: Prescriptive, Total UA (U-value x area) and Performance. For those working in states or jurisdictions where the 2015 IECC is in effect, there is yet another compliance path to choose from, the Energy Rating Index (ERI). The prescriptive compliance path has been the most common for a couple reasons: (1) it’s easy to follow, and (2) from the 2009 IECC and later, the performance path removed any potential flexibility for high efficient heating, cooling and water heating equipment. By removing any potential benefit to builders for using high efficient mechanical equipment it made the performance path nearly equivalent to using the prescriptive path. With the ERI compliance alternative in the 2015 and 2018 versions of the IECC, builders once again can do a true energy modeling analysis of their homes and get credit for installing high efficient mechanical equipment. Having certified RESNET HERS Raters involved in the verification of energy codes is a major opportunity for builders, strapped code jurisdictions and the rating industry. It ties code compliance by a third party with market opportunities for the builder.