While the underlying methodology for computing the ENERGY STAR scores did not change in the new Portfolio Manager, you may see slight score changes (up to 5 points) and other calculated metrics may differ slightly because we have updated various reference values used to compute site energy, source energy, emissions, and reference weather stations with recent data.
There are two changes that could cause a slightly larger score change (5-10 points).
- The introduction of new weather stations. We have more than tripled the number of weather stations in Portfolio Manager, which enables us to understand weather conditions at your property more accurately. In some cases (e.g. microclimates in California) the Heating Degree Days and/or Cooling Degree Days are more than 50% different at the new (closer) station. If you are located in California, near mountains, or in an area with other kinds of microclimates, you could see a score change of up to 10 points.
- New Parking Garage Assumptions. We updated procedures to account for ventilation in fully enclosed garages. If you have a fully enclosed garage that is open 24/7, you may see a lower score (by up to 10 points). To mitigate this, we recommend sub-metering parking garage energy consumption so that you may omit it from your property’s meter data.
The changes we’ve made bring the reference factors up to date allow us to provide more accurate scores. Because all of your metrics (including all prior year metrics) were updated, it is important to look at how your metrics changed over time.