A dead BMS is more common than no BMS
In many older offices the automation system exists but isn't working: years-old schedules, alarms switched off because they „kept ringing”, zones controlled by hand. Formally there is a BMS; in reality it doesn't run the building.
That can be worse than no system, because it creates an illusion of control. So the audit's first question is not „is there a BMS”, but „does anyone actually use it”.
What to actually check
Four areas tell the truth about the state of the automation. They don't need new hardware — they need a careful review of what is already there.
- Schedules — do they match real building use, or run around the clock.
- Setpoints — are they misaligned, contradictory or hard-coded.
- Alarms — are they handled, or ignored and muted.
- Trends — is historical data being collected and available at all.
Integration: do the systems talk
The second dimension is integration. HVAC, lighting, meters and access control often live in separate worlds — BACnet, Modbus, KNX, vendor protocols. Without a common layer you cannot analyse or optimise the building as a whole.
Assessing interoperability decides whether a retrofit will be „adding islands” or building a coherent architecture you can develop later.
Retro-commissioning before replacement
Surprisingly often the biggest effect comes not from replacement but from retro-commissioning — restoring the existing system to correct operation: fixing schedules, setpoints and control logic. It is a low-capital action with a high return.
Only when restoration isn't enough is modernising or replacing parts justified — and then on the basis of data, not a hunch.
From assessment to decision
The result of such an assessment is not a fault list, but a map: what to fix in the existing system, what to integrate, and what to genuinely replace. Each path has a different cost and a different return.
This is the foundation of Smart Retrofitting — delivery driven by diagnosis, not by a supplier's catalogue.
Before you replace the BMS, check whether the current one runs at all. The highest return often lies in restoration, not in a purchase.