EUI Calculator – Energy Use Intensity

Energy Use Intensity is expressed as energy per unit of building floor area over a specific timeframe, typically one year. The fundamental equation is EUI = Energy Consumption / Floor Area. Depending on your region and reporting standards, energy consumption is measured in kBtu or kilowatt-hours (kWh), while floor area is calculated in square feet (ft²) or square meters (m²). A lower EUI score generally indicates superior energy performance and lower operational expenses.

Imagine you manage a mid-sized commercial office building with a total floor area of 25,000 square feet. Over the course of the year, utility records show a total annual energy consumption of 1,750,000 kBtu. To find the EUI, divide the total energy consumption by the floor area: EUI = 1,750,000 kBtu / 25,000 ft². This yields an EUI of 70 kBtu per square foot per year. You can now compare this figure against regional benchmarks for similar office spaces to evaluate performance.

Always ensure your energy consumption data includes all fuel sources used on-site, such as electricity, natural gas, and district steam, converted into a common unit like kBtu. Keep your gross floor area measurements consistent by following standardized guidelines like building exterior dimensions. Finally, remember that building type drastically alters expectations; a data center will naturally feature a significantly higher EUI than a warehouse.