The EPA will introduce Heating Degree Days back into the ENERGY STAR Portfolio Manager scoring process for Office buildings, and the changes will be implemented July 21, 2019.

One year ago, EPA updated the performance metrics and model used to determine Office building Energy Star scores. This update was necessary to correct a shift in Energy Star scores which led to more than 50% of buildings receiving a score of 75 or higher. The changes resulted in a large decrease in Energy Star scores for many buildings, which caused many building owners to question the updates and feedback from many Portfolio Manager users indicated that the model changes seemed to result in larger-than-expected score decreases for some buildings, especially those in colder climates.

Based on this feedback, EPA instituted a review period to verify the model changes with respect to building size, fuel mix and climate (Heating Degree Days–HDD). The review is now complete and has resulted in changes to the 2018 model that will be implemented on July 21, 2019.

While developing the 2018 Model, EPA determined that the building HDD was not a significant metric and removed it from the model. Their review process has since determined that when warm climate buildings are excluded, this metric is significant and must be included to correctly calculate Energy Star scores for buildings with moderate to significant energy use for heating.

EPA has revised the 2018 model to include an HDD adjustment for buildings with an HDD of 924 and greater. This change has resulted in a tighter distribution of score changes and a smaller average score drop overall.

Changes to distribution of EPA Energy Star scores

The new model has also corrected the above average drop in Energy Star scores that was observed for cold climate buildings, and the number of buildings that receive an Energy Star Score of 75% or greater is now consistent across HDD ranges. When the HDD changes were included in the new model, other suspected criteria (building size and fuel mix) proved insignificant factors.

New Energy Star HDD Averages August 2018 adjustments compared to HDD model

What does the model change mean for my Energy Star score? Unfortunately, if your building is located in a warm climate like Southern California, the model change will have little impact on your Energy Star score. The good news is that your scores will not decrease. If you are in a cold climate like Seattle or Chicago (HDD >5000) you can expect an Energy Star score increase of 4 to 9 points. 

All Portfolio Manager users should download their building information by July 20th, 2019–before the model updates take effect. This will allow you to track any changes. Portfolio Manager will be down on July 21st, 2019 for the updates and the new scores will be available on Monday July 23rd, 2019.

If you have a building that was added to Portfolio Manager during the review process and have been waiting for Energy Star Certification, EPA will again issue these for Office buildings beginning July 31st, 2019.


Resource | Analysis and Key Findings from EPA’s Review

About Kathleen Martin

Katy came to Gridium with a background in Product Development. She has an SB and SM in Mechanical Engineering from MIT. Katy enjoys reading, camping, and cross-country road trips with her family.

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