Impacts
An analysis of roughly 800 test homes showed that savings in REM v15.4.1 are 4.5% higher than v15.3 on average. This positive impact can be traced to the correction of a bug in previous versions that improperly assigned LTO values in the reference home. REM Support personnel and their Version History page confirm this behavior.
A single home in the sample had a negative savings change of less than 1%.
Timeline
All homes submitted via the online Home Registration and Rebate System on or after November 1, 2017 will be processed in v15.4.1. Homes submitted in earlier versions will automatically be updated and processed in v15.4.1. No action is required from raters who plan to submit files created in earlier version.
**Note that future versions of REM/Rate will not be accepted until the RNC Program explicitly notifies all raters that the newest version's savings impacts have been adequately tested.