Calculate and benchmark your building's energy efficiency performance using the EUI metric.
Updated 5/6/2026
kWh
sq ft
0.17
kBtu/sq ft/yr
Efficiency Rating
Excellent (High Efficiency)
Performance Category
Excellent
Energy Use Intensity (EUI) is a metric that measures a building's annual energy consumption relative to its size. It represents the total energy used per square foot (or square meter) per year, allowing buildings of different sizes to be compared on equal footing. EUI standardizes energy performance, making it easy to identify efficiency opportunities and benchmark against similar buildings.
Think of EUI as the "miles per gallon" equivalent for buildings. A lower EUI indicates better energy efficiency, while a higher EUI suggests the building uses more energy than typical. EUI encompasses all energy sources including electricity, natural gas, steam, and other fuels consumed within a building annually.
Commercial buildings typically range from 40-80 kBtu/sq ft/year, but this varies significantly by building type. Data centers may exceed 150 kBtu/sq ft/year due to 24/7 operations, while high-efficiency office buildings can achieve EUI below 30 kBtu/sq ft/year. Building code compliance and LEED certification often reference EUI benchmarks.
EUI Benchmarks by Building Type
| Office | 40-80 |
| Retail | 50-90 |
| Hospital | 100-150 |
| School | 60-100 |
| Data Center | 100-200+ |
EUI Rating Scale
| Excellent | < 35 kBtu/sf |
| Good | 35-60 kBtu/sf |
| Average | 60-100 kBtu/sf |
| Poor | > 100 kBtu/sf |
Scenario: A 50,000 sq ft office building consumes 2,500,000 kWh of electricity and 5,000 therms of natural gas annually.
Step 1: Convert electricity to kBtu
2,500,000 kWh × 3.412 = 8,530,000 kBtu
Step 2: Convert natural gas to kBtu
5,000 therms × 100 = 500,000 kBtu
Step 3: Calculate total energy
8,530,000 + 500,000 = 9,030,000 kBtu
Step 4: Calculate EUI
9,030,000 kBtu ÷ 50,000 sq ft = 180.6 kBtu/sq ft/year
Result: This building has an EUI of 180.6 kBtu/sq ft/year, which is in the "Poor" category and significantly above the 40-80 benchmark for office buildings. Energy efficiency improvements should be prioritized.
EUI measures consumption per square foot regardless of energy prices, while energy cost varies with local rates and time-of-use pricing. A building with low EUI still has high costs in areas with expensive energy. Conversely, high-EUI buildings in low-cost regions may have lower bills, but are less efficient.
Annual EUI calculation is standard practice, typically reported on a fiscal or calendar year basis. Some buildings track EUI monthly to identify seasonal trends and anomalies. Regular tracking helps identify equipment degradation or operational issues early and demonstrates progress on energy efficiency initiatives.
Standard EUI doesn't account for climate directly, but EPA's ENERGY STAR uses "weather-normalized" EUI that adjusts for local heating and cooling degree-days. This allows fair comparison between buildings in different climates. Always specify whether data is raw or weather-normalized when comparing buildings.
Common improvements include upgrading HVAC systems, improving insulation and air sealing, replacing lighting with LED fixtures, optimizing controls and operational practices, and installing renewable energy. Energy audits identify the highest-return opportunities. Many buildings achieve 20-30% EUI reductions with systematic improvements.
Generally, EUI below 35 kBtu/sq ft/year is considered excellent for most commercial buildings. High-performance buildings (LEED Platinum, Passive House) may achieve 20-25 kBtu/sq ft/year. These require optimized design, high-efficiency systems, and superior envelope performance with minimal air leakage and infiltration.
On-site renewable generation (solar, wind) typically reduces EUI dollar-for-dollar by offsetting grid consumption. Some methodologies credit renewable generation as negative energy use. Purchased renewable credits or off-site solar don't reduce EUI under standard ASHRAE definitions, though some alternative frameworks differ.
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