What's the difference between BMS and iBMS?

A BMS controls and monitors a building's mechanical and electrical systems — HVAC, lighting, alarms, sometimes life safety. An iBMS adds the systems that historically sat outside the BMS's remit and brings them under one operating picture: energy monitoring, power quality, security, audio-visual, IT environmental.

When iBMS is the right call

• Multiple subsystems would otherwise have their own operator interfaces — true for most critical infrastructure.
• Energy optimisation has a measurable business case.
• Operational continuity depends on subsystem interactions (cooling + power; life safety + HVAC).
• Cyber posture demands one HMI to harden, one audit trail.

Where this lands on cost

iBMS is 20-40% more expensive to deliver than a BMS-only scope and meaningfully cheaper to operate over a 15-year horizon if the convergence value is real. The judgement is whether the operating savings justify the up-front.