Learn how weather normalization in ENERGY STAR Portfolio Manager affects your NYC Local Law 84 benchmarking score.
BY NYC Energy Code Team
ON
6 October 2026
How to Read Your ENERGY STAR Score: What a 75 vs a 50 Really Means
Seeing an ENERGY STAR score of 75 on a building dashboard can feel like getting a strong report card. Seeing a 50 may look mediocre.
But the numbers mean something much more specific than a simple percentage.
A score of 50 represents median energy performance among comparable buildings in the national reference population. A score of 75 means the property is performing at approximately the 75th percentile, meaning it performs better than roughly 75% of similar buildings in that comparison population. (energystar.gov)
For NYC owners, there is another important layer: the ENERGY STAR score is also used to determine the building's NYC energy efficiency grade under Local Law 33, as amended by Local Law 95.
That means the difference between 50 and 75 is not just an abstract number. It can affect how a building's energy performance is understood and, in NYC, the letter displayed on the property.
What Does an ENERGY STAR Score Actually Measure?
The ENERGY STAR score is a 1–100 comparative measure of whole-building energy performance.
It is not:
• 75% energy efficient
• 75% better than your neighbor
Instead, it compares the building's measured energy performance with a national population of similar buildings using the ENERGY STAR methodology.
EPA explains that the score considers the building's physical characteristics, operations, and how people use the building, rather than simply comparing raw energy consumption. (energystar.gov)
So a building's score is influenced by factors such as its property type, size, operating characteristics, climate, and actual energy consumption.
The Most Important Number: 50
A score of 50 is the median.
That means approximately half of the comparable buildings perform better and approximately half perform worse within the relevant statistical reference population.
It does not mean the building is using an excessive amount of energy.
It means its energy performance is roughly in the middle of the applicable comparison population.
Consider an office building with a score of 50. The owner should not immediately conclude:
“The building is inefficient.”
A better interpretation is:
“The building is performing around the national median for comparable properties under the ENERGY STAR methodology.”
That is a very different conclusion.
Then What Makes 75 Different?
A score of 75 is a significant step upward.
ENERGY STAR describes a score of 75 or higher as indicating that a building is a top energy performer and potentially eligible for ENERGY STAR certification, assuming all other certification requirements are satisfied. (energystar.gov)
Conceptually, the scale can be understood in performance bands:
| ENERGY STAR Score | General Meaning |
|---|---|
| 1–24 | Very low relative performance |
| 25–49 | Below median |
| 50 | National median |
| 51–74 | Above median |
| 75–100 | Top-performing range (Certification eligible) |
These are interpretive bands rather than separate certification categories. The key thresholds are 50 = median and 75 = top-performing threshold.
75 Does Not Mean the Building Uses 25% Less Energy
This is a common misunderstanding. A score of 75 does not mean:
❌ 25% less energy than average
The ENERGY STAR score is a statistical ranking, not a direct percentage-savings calculation.
A building with a score of 75 is performing better than roughly three-quarters of the comparable reference population, but the numerical difference between energy consumption levels is not necessarily 25%.
That is why you should never translate:
Score = 75 ≠ Energy use = 25% lower than average
The two numbers describe completely different metrics.
Why the Score Isn't Based Only on Utility Consumption
Imagine two office buildings:
Building A
Consumes 1 million kWh per year.
Building B
Consumes 700,000 kWh per year.
It would be tempting to assume Building B must have the better ENERGY STAR score. But that conclusion could be entirely wrong.
The buildings may differ in:
- Floor area and gross square footage
- Weekly operating hours
- Worker density and occupancy levels
- Climate zone and weather extremes
- Primary property use and tenant computing load
- Other operating characteristics used by the EPA regression models
EPA explains that the ENERGY STAR score normalizes for factors such as business activity and climate so that buildings with different operating conditions can be compared more fairly. (energystar.gov)
That is why the score is more useful than simply comparing total kWh between unrelated buildings.
Site Energy vs. Source Energy
Another reason the score can be confusing is that Portfolio Manager shows several energy metrics.
Site energy: Represents the energy consumed directly at the property (what shows on your utility meters).
Source energy: Accounts for the total energy required to produce and deliver that power, including upstream generation, transmission, and distribution losses.
EPA uses source energy as the basis for the ENERGY STAR score because it provides a more consistent basis for comparing buildings using different types of energy. (energystar.gov)
This means an owner looking at a utility bill is not necessarily looking at the exact metric used to generate the 1–100 score.
Weather Matters Too
A building's energy use changes with weather. A particularly hot summer can increase cooling energy. An unusually cold winter can increase heating consumption.
The ENERGY STAR methodology accounts for weather differences when determining the score for eligible property types. EPA notes that the methodology incorporates regional weather and other relevant operating characteristics. (energystar.gov)
This allows buildings in different climates and years with different weather conditions to be compared more meaningfully.
That is also why the score should not be interpreted as simply: “How many kilowatt-hours did we use?”
It is closer to: “How well did this building perform relative to comparable buildings after the methodology accounts for important differences?”
What Does a 75 vs. 50 Mean for an NYC Building?
This is where the ENERGY STAR score connects directly to NYC regulation.
NYC's Local Law 33, as amended by Local Law 95, requires applicable buildings to display an energy efficiency score and letter grade.
The current NYC grading scale is:
| ENERGY STAR Score | NYC Energy Grade |
|---|---|
| 85–100 | Grade A |
| 70–84 | Grade B |
| 55–69 | Grade C |
| Below 55 | Grade D |
| Required benchmarking not submitted | Grade F |
| Exempt / not covered by ENERGY STAR program | Grade N |
NYC DOB confirms that the letter grade is based on the ENERGY STAR score generated through ENERGY STAR Portfolio Manager. (nyc.gov)
That creates a dramatic result:
ENERGY STAR 75 → NYC Grade B
ENERGY STAR 50 → NYC Grade D
A difference of just 25 points on the 1–100 score therefore corresponds to a substantial difference in NYC's publicly displayed energy grade.
Why 75 Can Feel Better Than It Looks
For NYC owners, a score of 75 is actually stronger than the letter grade might initially suggest.
A 75 is already in the top-performing range according to ENERGY STAR. But NYC does not assign an A until the score reaches 85.
75–84: ENERGY STAR top performer → NYC Grade B
85+: ENERGY STAR top performer → NYC Grade A
This is an important distinction. A building with a 75 is not performing poorly simply because its NYC grade says B rather than A. The NYC grade is a regulatory disclosure scale, while the ENERGY STAR score is a national comparative performance metric.
What a Score of 50 Should Trigger
A score of 50 should generally be treated as a starting point for investigation, not proof that the building needs a major retrofit.
EPA specifically describes the ENERGY STAR score as a screening tool. It can indicate how a property performs but does not explain exactly why it received that score or which equipment should be upgraded. (energystar.gov)
For example, a score of 50 could lead an owner to investigate:
- HVAC operation, runtime schedules, and temperature setpoints
- Interior and exterior lighting controls
- Building automation system (BAS) programming and sensors
- Building envelope infiltration and insulation continuity
- Tenant occupancy schedules and plug-load density
- Year-over-year energy-use trends
The right next step depends on what the underlying operational data shows.
A Score of 75 Doesn't Mean “Stop Improving”
The opposite mistake is assuming that a good score means there is nothing left to do.
A building with a 75 can still have:
• Inefficient equipment
• Poor controls or simultaneous heating and cooling
• High maintenance costs
• Unnecessary operating hours
• Future Local Law 97 emissions cap compliance risks
The ENERGY STAR score is a whole-building benchmark. It does not certify that every piece of equipment is optimized.
For example, an owner may discover that one HVAC system is operating inefficiently even though the overall building still performs well compared with its peers.
Why the Score Can Change Year-Over-Year
A building's ENERGY STAR score can move from year to year.
Suppose an office building drops from 75 → 68. That does not automatically mean a major piece of equipment failed. The change could be associated with:
- Weather variations (e.g., severe summer cooling degree days)
- Changes in tenant occupancy or leasing rates
- Adjusted operating schedules (longer building operating hours)
- Shift in submetered plug loads or server density
- Updates to EPA's national reference surveys (CBECS updates)
Likewise, a jump from 50 to 65 does not necessarily mean one specific retrofit caused the entire improvement. The score should therefore be analyzed alongside the building's operational history.
ENERGY STAR Score vs. EUI
Owners should also keep an eye on Energy Use Intensity (EUI).
EUI measures energy consumption relative to building size, commonly expressed as energy per square foot per year (kBtu/sq.ft./yr). ENERGY STAR provides both site and source EUI metrics in Portfolio Manager. (energystar.gov)
EUI
How much energy does the building consume per unit of area?
ENERGY STAR Score
How does its performance compare with similar buildings nationally?
Neither replaces the other. A property manager reviewing a building's performance should ideally look at both metrics simultaneously.
A Practical Example
Consider two NYC office properties:
| Metric | Building A | Building B |
|---|---|---|
| ENERGY STAR Score | 75 | 50 |
| NYC Energy Grade | B | D |
| Relative Position | Top-performing range | Around median |
| Immediate Conclusion | Strong performance | Worth investigating |
Building B should probably receive more attention, but that does not automatically mean it needs a $1 million retrofit.
The next step should be diagnosis. Perhaps the problem is HVAC scheduling rather than HVAC equipment. Or perhaps the building has an inefficient envelope. The score identifies the signal. More detailed analysis identifies the cause.
Can You Increase a 50 to a 75?
Potentially, but there is no universal retrofit recipe.
A building might improve performance through a combination of:
Better HVAC operation + controls optimization + efficient lighting + envelope improvements + equipment upgrades
The appropriate measures depend on where the building is currently losing energy.
EPA recommends using benchmarking results to identify buildings that offer opportunities for improvement and then investigating the causes of poor performance. (energystar.gov)
In practice, that means the path from 50 to 75 is rarely:
Benchmark → Diagnose → Prioritize → Improve → Re-benchmark
Not Every Building Gets a Score
Another important limitation is that not every property type is eligible for a 1–100 ENERGY STAR score.
EPA currently lists eligible property types including offices, hotels, multifamily housing, hospitals, retail stores, warehouses, schools, supermarkets, and several others. (energystar.gov)
Properties without an eligible score can still use Portfolio Manager to track energy consumption and other metrics, but they do not automatically receive a 1–100 ENERGY STAR score.
That distinction is important when interpreting an NYC energy grade of N, which can indicate a property that is exempt from benchmarking or not covered by the ENERGY STAR program. (nyc.gov)
How Building Owners Should Read the Number
A good way to interpret the score is:
- Score of 50: “We're around the national median for comparable buildings.” This is a useful baseline and may justify further investigation.
- Score of 75: “We're performing better than roughly three-quarters of the applicable comparison population.” This is strong relative performance and may qualify the property for ENERGY STAR certification if all other requirements are met.
- Score of 85+: “We're both in the top-performing range and, under NYC's current grading scale, in the A-grade range.” That distinction is particularly relevant for NYC properties.
The Number Is More Useful as a Trend
One year's score provides a snapshot. Several years of data provide a story.
Imagine a historical progression:
2023: 48 → 2024: 55 → 2025: 67 → 2026: 76
That trend indicates meaningful improvement, especially if major building-performance upgrades occurred during the same period. But the owner should still examine the underlying data to understand what actually changed.
Conversely, a drop from 78 → 61 deserves prompt investigation even if the building appears to be operating normally.
The most valuable question is not merely: “What is our score?” It is: “Why did our score change?”
Common Mistakes
1
Treating 75 as 75% Efficiency
The score is a comparative percentile ranking against a national peer population, not a percentage of energy efficiency.
2
Treating 50 as a Failure
50 represents the national median, not a failing score. It indicates typical performance.
3
Assuming 75 Means an NYC A Grade
It does not. NYC currently assigns an A at 85 or higher. A score of 75 falls in the B range (70–84).
4
Looking Only at the Letter Grade
The underlying ENERGY STAR score, weather-normalized data, and EUI provide far more actionable engineering insight than a letter on a plaque.
5
Assuming a High Score Means Every System Is Efficient
The score evaluates whole-building aggregate performance. It does not certify that individual chillers, boilers, or distribution loops are optimized.
Conclusion
The difference between an ENERGY STAR score of 75 and 50 is substantial, but it is easy to misunderstand what those numbers actually represent.
A 50 is the national median for comparable buildings under the ENERGY STAR methodology. A 75 is approximately the 75th percentile, placing the property in the top-performing range. (energystar.gov)
For NYC owners, the difference becomes even more visible because the score feeds directly into the City's energy-grading system:
- 50 → Grade D
- 75 → Grade B
- 85+ → Grade A
under the current NYC grading scale. (nyc.gov)
But neither number tells you exactly why the building performs the way it does.
That's why the smartest way to use the ENERGY STAR score is as a screening and trend-tracking tool. Look at the score together with EUI, actual energy consumption, operating conditions, and building-system performance.
A score is valuable not because it tells the whole story, but because it tells you where to start asking better questions.
Frequently Asked Questions
A score of 50 represents median energy performance among comparable properties in the relevant national reference population. It does not mean the building is 50% efficient. (energystar.gov)
A score of 75 indicates performance around the 75th percentile of comparable properties, putting the building in the top-performing range. A score of 75 or higher can also make an eligible property potentially eligible for ENERGY STAR certification, subject to other requirements. (energystar.gov)
Yes. ENERGY STAR considers 75 or higher to represent top energy performance. (energystar.gov)
No. NYC's current energy-grading scale assigns B to scores from 70 through 84 and A to scores of 85 or higher. (nyc.gov)
Not necessarily. It means the building is around the median relative to comparable properties. It can still be worth investigating whether specific systems or operating practices offer cost-effective improvement opportunities.
EPA uses actual measured energy data and accounts for relevant building characteristics, operating conditions, and climate factors. The methodology varies by eligible property type and uses nationally representative survey data as the basis for comparison. (energystar.gov)
The 1–100 ENERGY STAR score uses source energy. EPA considers source energy a more equitable basis for comparing buildings because it accounts for energy used to produce and deliver the energy consumed at the property. (energystar.gov)
Potentially. Reducing unnecessary energy use through better equipment, controls, operations, and other efficiency measures can improve building performance. The actual change in score depends on the property's resulting performance relative to its reference population.
No. EPA describes the ENERGY STAR score as a screening tool rather than a diagnostic tool. A lower score can identify a property worth investigating, but additional analysis is needed to determine the underlying causes. (energystar.gov)
No. Only property types that meet EPA's eligibility requirements receive a 1–100 score. Other properties can still benchmark through Portfolio Manager and may receive an NYC grade of N when they are not covered by the ENERGY STAR scoring program. (energystar.gov) (nyc.gov)