Resource search

Search DataDrivenAEC

Type at least two characters to search.

Looking for live projects? Explore open projects or browse the feed.

Open the full search page →

Site EUI arithmeticFree

Building Site EUI
Calculator

Divide a user-entered annual site-energy total by the matching floor area. The result is a normalized arithmetic indicator, not a code, certification, or peer benchmark.

Who it's for: facilities managers and energy consultants normalizing a consistent 12-month site-energy total at post-occupancy operations review, by the floor-area boundary used for that same dataset.

1
Enter floor area + annual energy
Use gross floor area (GFA). Annual energy from utility bills or energy model — heating + cooling + lighting + plug loads
2
Confirm matching boundaries
The energy period, included fuels, and floor-area definition must be consistent before comparing results
3
Calculate site EUI
kWh/m²/yr only; select any external benchmark separately
EUI = total energy / floor area
EUI = annual site energy (kWh) ÷ floor area (m²). This tool does not convert fuels, weather-normalize consumption, define the floor-area boundary, or select a comparison target.
EUI Calculator
Site EUI · kWh/m²/yr

Prefilled values are a worked example. Replace them with your figures and select Calculate.

Annual site-energy inputs
From utility bills or energy model. Include all end uses.

How to use this calculator

1
Enter the floor area (m²)
Use the same documented floor-area boundary that any later comparison dataset uses.
2
Enter annual site energy (kWh/yr)
Use a consistent 12-month total with all included fuels already converted to kWh on a declared site-energy basis.
3
Read the arithmetic result
The result is annual kWh divided by m². It does not assign a rating or determine compliance.

The formula

Site EUI = Annual site energy (kWh/yr) ÷ Floor area (m²)

Both inputs must use documented, matching boundaries. The formula itself does not define which fuels, meters, spaces, or operating period belong in the numerator or denominator.

Worked example

Example
A building with a documented 5,000 m² comparison area and 375,000 kWh of annual site energy has an EUI of 375,000 ÷ 5,000 = 75.0 kWh/m²/yr. Compare 75 only with a dataset using compatible energy and area definitions.

When this estimate will be off

  • Does not convert fuels or calculate source energy, greenhouse-gas intensity, cost, or weather normalization.
  • Does not choose a code, certification, peer group, climate, occupancy, or operating-hours benchmark.
  • Use a consistent 12-month energy total. Document vacancy, changed operating hours, renovations and missing meters; this calculation neither adjusts for them nor establishes a performance rating.
  • A whole-building EUI can describe a mixed-use total. Any zone comparison needs matching energy and area boundaries; the tool cannot allocate shared meters or establish comparable operating conditions.

Frequently asked questions

Using energy and area figures that cover different spaces or periods. Align meter coverage, energy units and the floor-area definition before dividing.

EUI is annual energy consumption divided by floor area, expressed here in kWh/m²/yr on a site-energy basis. It normalizes for size, not for different uses, climates or operating conditions. A lower value alone does not prove better efficiency or make a clinic directly comparable to a hospital.

This calculator intentionally does not answer that question. A meaningful comparison requires a compatible dataset and definitions for climate, occupancy, operating hours, fuels, site/source basis, and floor area.

No. It performs one division and returns a site-EUI indicator. Compliance and certification require their own methods, inputs, and approved benchmarks.

Sources

This free Building Site EUI Calculator is built and maintained by DataDrivenAEC, using the relevant codes and standards. It does not substitute for professional judgment.