What systems does commissioning cover?

Any building system whose performance has to be verified, not just installed: HVAC and controls, electrical distribution and emergency power, fire alarm and life-safety systems, plumbing and domestic water, and increasingly building automation and energy systems. Scope is defined in the project’s commissioning plan, which lists each system, the acceptance criteria, and who tests it, the installing contractor, a third-party commissioning agent, or both, so testing is not left to chance at the end of the job.

What is the difference between commissioning and a final inspection?

A final inspection confirms a system is installed correctly and code-compliant at a point in time; commissioning confirms it actually performs as designed under real operating conditions, often across multiple modes, like a chiller plant running in both occupied and unoccupied sequences. Commissioning is a process with install checks, startup, functional performance testing, and owner acceptance; an inspection is usually a single pass or fail visit. A system can pass inspection and still fail commissioning if it runs but does not perform the way the design intended.

When does commissioning happen relative to substantial completion?

Functional testing is typically scheduled to finish before or right around substantial completion, since many owners require commissioning sign-off as a condition of occupancy, and the warranty period that substantial completion starts assumes the systems are actually working. In practice, commissioning often starts earlier, during installation, with pre-functional checks, and can extend past substantial completion into a seasonal or deferred testing period for systems, like heating and cooling, that cannot be fully tested outside their operating season.

Construction Glossary · Quality & Field

CommissioningCx

Installed is not the same as working. Commissioning is the proof that every system does what the design said it would.

Definition

Commissioning is the systematic process of verifying that building systems, HVAC, electrical, controls, and life safety, are installed and perform as the design intended. It moves through install checks, functional testing, and owner acceptance, confirming the building actually works before it is handed over.

Five stages, one gate at a time

Commissioning is not a single test at the end. It is a sequence, install, start-up, functional test, verify, accept, and a system that stalls at one stage does not move to the next until it is resolved.

What gets tested, and by whom

The commissioning plan assigns each system to a tester before the testing starts.

System	What gets tested	Who verifies
HVAC & controls	Sequences, setpoints, airflow under real load	Commissioning agent + installer
Electrical & emergency power	Transfer switches, generator start, load testing	Electrical sub + commissioning agent
Fire alarm & life safety	Detection, notification, interlocks with HVAC and doors	AHJ + fire alarm sub

Passing a construction inspection confirms the install; passing commissioning confirms it works, and both are typically closed out before substantial completion.

How POD handles commissioning records

POD reads the daily records and checklists that document commissioning activity where you log them. POD does not run commissioning or issue the certificates.

Construction daily report guide

Frequently asked questions

Accepted is the last stage, not the first test

Commissioning sign-off is usually the condition that lets a building move toward occupancy.

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