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Commissioning

Commissioning is the final pre-handover stage testing every installed system. What gets commissioned, who signs, and the paperwork that lands in the build pack.

By Chalkline. Last updated 14 May 2026. Verified 14 May 2026.

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Commissioning is the final pre-handover stage of a residential build where every installed service is energised, tested under operating conditions, balanced, and signed off. It happens after second-fix and before practical completion. A site that has not been fully commissioned cannot be lawfully occupied; commissioning paperwork is part of the evidence the certifier wants before issuing the Occupation Certificate.

What typically gets commissioned on a Class 1 or Class 2 residential job:

  • Electrical: switchboard energisation, RCD trip tests, circuit identification, smoke alarm interconnection. The licensed electrician issues a Certificate of Compliance Electrical Work (or state equivalent).
  • Gas: pressure test, appliance light-up, leak check. The licensed gasfitter issues a Gas Certificate of Compliance under AS/NZS 5601.1.
  • Plumbing and drainage: hydraulic pressure test, drainage test, fixture flow and pressure check per AS 3500. The licensed plumber issues a Certificate of Compliance.
  • Hot water unit (HWU): filling, energising, temperature set per the AS 3500 / TMV requirements.
  • HVAC (ducted heating, cooling, ventilation): airflow balancing across registers, refrigerant charge check, condensate drainage check. The HVAC contractor issues a test-and-balance (T&B) report.
  • Solar PV and battery: inverter commissioning, isolator labelling, network connection sign-off.
  • Fire detection and emergency lighting (mainly Class 2): alarm test, battery backup test, AS 1670 / AS 2293 sign-off where applicable.
  • Swimming pool, spa, bore pump: filling, pump priming, chlorinator commissioning.

Paperwork in the build pack. Each commissioning step ends with a written certificate from the licensed trade. The builder collates these into the handover pack along with appliance manuals, warranty cards, and as-built drawings. Missing certificates delay the certifier and delay handover.

Common builder mistake. Booking the final certifier inspection before HVAC balancing or solar PV grid sign-off has completed. Those two items typically have the longest lead times; book them as early as the schedule allows.

Also known as: system commissioning, T&B, test and balance.

Category: Pre-handover / completion / certificates.

See also

Last updated: 2026-05-14. Verified: 2026-05-14.

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