In general, EPA strives to update each ENERGY STAR score at least once every five years. However, because EPA depends on a variety of external sources for the score, including DOE's Commercial Building Energy Consumption Survey (CBECS) for many U.S. property types, this is not always possible. More on CBECS 2012 update.
The purpose of updating the calculations is to reflect the current state of commercial facilities and their energy consumption, and to allow for a more up-to-date comparison of facilities. These enhancements generally cause slight score changes; some facilities' scores will increase, while others will decrease or remained unchanged.
Because the ENERGY STAR score provides a national peer-group evaluation it is not possible to update the calculations in the absence of reliable national reference data. We regularly monitor the status of representative national survey data to ensure that the ENERGY STAR is as accurate and as up-to-date as possible.
EPA will provide advance notice to all Portfolio Manager users before any future model changes take place.