The rise of connected building systems has generated an enormous volume of operational data. But data without a framework for measurement is just noise. The facilities managers who are getting real value from their building intelligence investments are those who have defined a small number of high-signal KPIs and are tracking them consistently over time.
Here are the five metrics we recommend as the foundation of any building performance measurement programme.
1. Energy Use Intensity (EUI)
EUI — typically measured in kWh/m²/year — is the single most useful metric for comparing a building’s energy performance over time or against peers. Track it monthly, break it down by end-use category (HVAC, lighting, IT, other), and set a 3-year reduction target aligned to your carbon commitments.
2. Thermal Comfort Compliance
Using temperature and humidity sensors, measure the percentage of occupied hours during which each zone is within its defined comfort band (typically 22–24°C, 40–60% RH). A zone that spends more than 15% of occupied hours outside its comfort range warrants investigation.
3. Reactive vs Planned Maintenance Ratio
A healthy M&E estate should see reactive maintenance (emergency callouts, unplanned repairs) represent no more than 20% of total maintenance spend. A higher ratio indicates either an ageing asset base, inadequate PPM coverage, or both.
4. Space Utilisation Rate
Occupancy sensors and meeting room booking data can reveal actual versus booked space utilisation. A building where meeting rooms are booked but unused 40% of the time is wasting heating, cooling and lighting energy — and potentially justifies a reconfiguration of the floor plate.
5. System Fault Mean Time to Resolution (MTTR)
How long does it take from fault detection to resolution for each system category? MTTR is a direct measure of the effectiveness of your maintenance provision. Track it monthly, broken down by system type, and use it to hold your service providers accountable.
