Energy modeling software changes

Energy modeling software provides detailed snapshots of homes that the RNC Program uses to determine energy savings and incentives. Until last year, HERS raters in the Program submitted homes in one specific energy modeling software (REM/Rate). Beginning in early spring of 2018, the Program began accepting a new software called Ekotrope that has quickly grown in popularity.

For a variety of reasons the Program has elected to use Ekotrope for all energy modeling moving forward.

  1. Consistency - using one software to determine incentives means that all homes are treated the same.

  2. Efficiency - Ekotrope is a cloud-based software that allows for faster processing of incentive applications. That means checks will get to builders more quickly.

  3. Flexibility - Due to the cloud-based nature of Ekotrope, updates and fixes are easier to manage. This means fewer surprises resulting from a software update or a version change.

Use of Ekotrope over time

Y-axis indicates % of all homes

75% of homes in the Program are already submitted using Ekotrope, so there is a very good chance that you will not be affected by this change. Builders whose homes are currently being submitted using REM/Rate may see impacts to homes’ HERO compliance and incentives. In a test of over 300 homes, the median impact of moving from REM/Rate to Ekotrope was an incentive reduction of less than 3%. It is also possible that some homes that passed HERO in the old software might not pass in the new software (and vice versa). It is critical that builders confer with their raters to determine if any updates are required to maintain HERO compliance.

**Please note that Program staff are available to assist by analyzing homes that appear to be improperly impacted by the change. Raters should contact with questions.**

What builders should do:

Ask your rater…

  • Are my homes already modeled using Ekotrope?

    • If yes, you’re all set. You’ll see no impacts from this change.

    • If no, move to the next bullets.

  • How do my homes perform in the new software? (HERO compliance and incentives)

    • It is important to review your homes’ compliance with the HERO code. It is possible that some specifications will need to be updated to maintain HERO compliance.

Be aware of the timeline…

  • Homes with permit dates prior to 9/1/2019 may continue to use REM/Rate to demonstrate HERO compliance. This provides ample time for builders and raters to connect and iron out any details mentioned in the bullets above.

  • Homes submitted beggining in early July will use the new software for incentive assignment (regardless of permit date). All raters have access to the new system and are able to provide incentive estimates for affected homes. As mentioned above, incentive impacts were found to be minimal.

Please feel free to contact the Program at with any questions or concerns.