Energy Use Intensity (EUI): A Guide to Building Efficiency (2025)
As sustainability becomes an essential focus for businesses, Energy Use Intensity (EUI) has become a key metric for measuring building efficiency. It calculates a building’s total annual energy consumption relative to its overall floor area. The lower your commercial building’s EUI energy, the more efficient it is.
This article explores energy usage intensity and how you can use energy-efficient solutions to improve your building’s sustainability rating.
What is Energy Use Intensity (EUI)?
EUI is measured in two primary ways: Site EUI and Source EUI.
- Site EUI refers to the energy consumed on-site, as shown in utility bills.
- Source EUI considers the total energy used, including generation and transmission losses, offering deeper insight into environmental impact.
Understanding source EUI vs site EUI is key when setting or evaluating sustainability goals.
Calculating EUI
Energy use intensity is typically expressed in kWh/m²/year or kBtu/ft²/year:
EUI = Total Energy Consumed Annually / Gross Floor Area
Different building types have different EUI values. For instance, hospitals and factories usually have a higher energy usage intensity than small office complexes.
Why EUI Matters for Sustainability
Buildings contribute to around 40% of global energy use, making EUI a critical benchmark for comparing and improving building performance. It helps in:
- Identifying inefficiencies
- Reducing operational costs
- Minimizing environmental impact
- Meeting regulations
- Attracting green-minded tenants and investors
Improving EUI with Smart Building Solutions
Modern solutions can significantly reduce EUI energy:
- Smart HVAC systems adjust temperatures based on occupancy and climate
- Building automation systems integrate HVAC and lighting controls to reduce power use
- Intelligent lighting with scheduling, daylighting, and occupancy-based control saves electricity
- Real-time monitoring helps track trends and detect anomalies for better decision-making
Practical Steps to Reduce Energy Use Intensity
- Upgrade HVAC and lighting systems with smart controls
- Install sensors for improved monitoring
- Switch to renewable energy sources (e.g., solar, wind)
- Educate building occupants to encourage energy-saving behaviors
- Retrofit buildings with energy-efficient equipment
For example, according to UKGBC, retrofitting can reduce energy usage intensity by 15–20% and yield substantial cost savings.
Conclusion
As the world moves towards net zero, Energy Use Intensity (EUI) is becoming crucial in shaping efficient commercial buildings. It’s more than just a number; it’s a guide to improving sustainability, reducing costs, and increasing building performance.
Rensair’s SDCV solutions offer the cost of a light retrofit with the energy impact of a deep retrofit, making us a smart choice for top tenants like Salesforce.
Want to cut energy use and costs? Contact us today to start your journey toward a more sustainable building.
Frequently Asked Questions
1. What is a good EUI score for commercial buildings?
A good EUI score depends on the building type and location, but generally, a lower EUI means better energy performance. For example, office buildings often aim for an EUI below 100 kWh/m²/year.
2. How often should a building’s EUI be evaluated?
EUI should be reviewed annually to track performance trends, assess the impact of upgrades, and ensure progress toward energy efficiency goals.
3. Can EUI be used to benchmark against other buildings?
Yes, EUI is commonly used to benchmark energy performance against similar building types, helping identify areas for improvement and set realistic efficiency targets.