Why Did My ENERGY STAR Score Go Down?
If your ENERGY STAR score recently decreased, do not assume your building suddenly became inefficient.
A lower score can result from increased energy consumption, changes in building operations, missing meter data, inaccurate property details, occupancy changes, unusual weather, or equipment and control problems.
The first step is to determine whether the change reflects a real decline in building performance or simply a problem with the information entered into ENERGY STAR Portfolio Manager.
In most cases, owners should compare the current reporting period with the previous year, review every energy meter, confirm property-use details, and investigate any changes in occupancy, operating hours, equipment, or tenant activity.
Here are the most common reasons an ENERGY STAR score goes down and what building owners should check.
1. Missing or Inaccurate Meter Data
Meter data should be the first place you look when a Portfolio Manager score decreases unexpectedly.
ENERGY STAR Portfolio Manager needs complete, whole-building energy information to evaluate performance accurately. If a meter is missing, entered twice, assigned to the wrong property, or contains incorrect dates, the resulting score may not reflect actual building performance.
Common meter problems include:
Missing utility bills
Overlapping billing periods
Duplicate meter entries
Estimated readings replacing actual use
Incorrect units
Meters that were added or removed during the year
Tenant meters that are not included
Utility data connections that stopped updating
Solar generation entered incorrectly
A meter accidentally excluded from performance metrics
Review at least 12 consecutive months of electricity, natural gas, district energy, and other fuel data. Compare Portfolio Manager totals with utility statements and confirm that every meter serving the property is included.
A sudden spike or gap is often easier to identify in a monthly energy-use chart than in the annual score itself.
2. Increased Operating Hours
Your building may simply be operating longer than it did during the previous reporting period.
An office that adds evening shifts, a retail property that extends weekend hours, or a medical building that begins operating seven days per week will usually consume more energy.
Portfolio Manager uses certain operating characteristics when comparing a property with similar buildings, but updated operating hours still need to be entered correctly. If the building is running longer while the property-use details remain unchanged, the score may decrease.
Ask:
Did tenants expand their schedules?
Did weekend occupancy increase?
Did cleaning or security hours change?
Are systems starting earlier or shutting down later?
Did a formerly vacant space become active?
Were temporary HVAC overrides left in place?
Even when longer hours are legitimate, HVAC, lighting, and ventilation schedules should still match actual occupancy as closely as possible.
3. Occupancy Changes
Occupancy can affect both energy consumption and the operating information used to calculate an ENERGY STAR score.
A building may use more energy after new tenants move in, especially when previously vacant areas become occupied. More people can mean greater cooling demand, additional ventilation, more computers, longer elevator operation, increased domestic hot-water use, and heavier use of common areas.
The opposite situation can also create confusing results. A building with lower occupancy may not reduce its energy use proportionally. Central HVAC systems, lighting, pumps, and ventilation may continue operating almost as they did when the building was full.
Review changes in:
Occupancy percentage
Number of workers
Number of residential units occupied
Tenant mix
Vacancy
Shift schedules
Use of common areas
Special operating conditions
Update the applicable property-use details in Portfolio Manager and make sure the effective dates match when the change occurred.
4. Incorrect Property-Use Details
ENERGY STAR Portfolio Manager does not evaluate every building in exactly the same way. It compares eligible properties with similar buildings while considering characteristics related to their use and operation.
Incorrect property-use details can therefore affect the score.
Depending on the property type, relevant inputs may include:
Gross floor area
Weekly operating hours
Number of workers
Number of computers
Occupancy
Number of units or rooms
Seating capacity
Refrigeration cases
Licensed beds
Parking area
Percent of the property that is heated or cooled
A common error is failing to update these details after a renovation, tenant change, expansion, conversion, or change in operating schedule.
Gross floor area deserves particular attention. If the area is entered incorrectly, the building’s energy use intensity and other performance metrics may be distorted.
Also confirm that each portion of a mixed-use property is categorized correctly. A building containing offices, retail, restaurants, parking, and data-center space should not automatically be entered as one uniform property use.
5. Weather and Normalization
A hotter summer or colder winter can increase HVAC energy use even when the building is operated reasonably well.
ENERGY STAR scoring accounts for climate and weather, which helps create a fairer comparison between buildings in different locations and reporting periods. However, weather normalization does not make actual energy consumption irrelevant.
A prolonged heat wave may expose:
Undersized or poorly performing cooling systems
Excessive cooling setpoints
Simultaneous heating and cooling
Dirty coils
Poor economizer operation
Increased peak demand
Controls that are not responding properly
Likewise, a cold winter may expose envelope leakage, poor heating controls, failed sensors, or inefficient boilers.
Compare both actual and weather-normalized energy-use metrics. If actual consumption increased sharply, investigate what happened operationally rather than assuming weather explains everything.
6. Equipment or Control Problems
Sometimes a declining score reflects a real building-performance problem.
Mechanical equipment can continue operating without completely failing. A stuck damper, failed sensor, leaking valve, overridden schedule, dirty filter, or poorly tuned control sequence may increase energy use for months without causing an obvious emergency.
Common operational causes include:
HVAC systems running after hours
Simultaneous heating and cooling
Incorrect temperature setpoints
Failed or inaccurate sensors
Disabled economizers
Stuck dampers or valves
Dirty coils and filters
Excessive ventilation
Poor boiler or chiller sequencing
Equipment short-cycling
Controls left in manual override
Compare monthly energy use with previous years and look for changes that correspond with maintenance events, complaints, renovations, or controls work.
An energy audit or retro-commissioning investigation can help determine whether the increase is caused by equipment condition, controls, scheduling, or another operational issue.
7. Increased Plug or Process Loads
Not every increase comes from the central HVAC system.
Modern commercial buildings contain growing numbers of computers, monitors, servers, kitchen appliances, charging stations, medical devices, laboratory equipment, refrigeration systems, and other plug or process loads.
A tenant may install new equipment without notifying the property manager. A small server room may expand. A restaurant may add refrigeration. An office may increase workstation density. Electric vehicle charging may appear as additional property electricity use.
These loads can increase both direct electricity consumption and cooling demand.
Review recent changes such as:
New tenant equipment
Additional computers or servers
Commercial kitchen expansion
New refrigeration
EV charging
Laboratory or medical equipment
Portable heaters
Supplemental cooling systems
Increased production or process activity
When possible, use submeters or interval utility data to identify when and where the increase is occurring.
How to Improve an ENERGY STAR Score
To improve an ENERGY STAR score, begin with accuracy before investing in new equipment.
Use this order:
Confirm all meters and utility entries.
Verify gross floor area and property type.
Update occupancy and operating characteristics.
Compare monthly consumption with prior years.
Review nights, weekends, and peak-demand periods.
Inspect HVAC schedules, setpoints, sensors, and controls.
Identify new plug or process loads.
Correct maintenance and operational problems.
Consider an energy audit or retro-commissioning study.
Continue monitoring performance after changes are made.
Do not change Portfolio Manager inputs simply to produce a better score. Property information should accurately represent how the building operated during the reporting period.
The goal is not to make the score look better. It is to understand why it changed and improve the building’s actual performance.
Final Takeaway
When owners ask, “Why did my ENERGY STAR score go down?” the answer is rarely visible in the score alone.
The decrease may come from bad meter data, longer operating hours, occupancy changes, incorrect property-use details, unusual weather, equipment problems, or new plug and process loads.
Start by validating the data. Then investigate the building.
A Portfolio Manager score is a useful warning signal, but it is not a diagnosis. The real value comes from finding the reason behind the change and turning that information into practical action.
IE Energy helps commercial building owners review benchmarking data, identify performance issues, complete energy audits, and develop practical recommendations for improving building operations.
