Commissioning is a quality process that checks a building's systems are designed, installed, tested and able to operate according to the owner's requirements. It starts during design and continues past handover, and its purpose is simple: to make sure the building works on day one and that the people running it know how to keep it working.
Why commissioning matters
Construction involves many trades, each focused on their own scope. Mechanical, electrical, controls, plumbing and fire protection systems all have to work together, and the gaps between contracts are where problems hide. Typical results of skipping commissioning include equipment that runs around the clock, rooms that never reach temperature, ventilation that does not meet design, alarms that do not reach anyone, and operators who were never shown how anything works.
These problems are far cheaper to find before occupancy, while contractors are still on site and warranties are fresh.
Commissioning across the project
Pre-design and design
- Owner's project requirements (OPR): a document that states what the owner needs from the building, such as comfort conditions, hours of use, energy goals, maintenance capabilities and future flexibility.
- Basis of design: the design team's explanation of how the systems will meet the OPR.
- Design reviews: the commissioning provider reviews drawings and specifications for coordination, maintainability and testability.
- Commissioning specifications: requirements written into the contract documents so contractors know what testing and documentation they owe.
Construction
- Review of equipment submittals against the design.
- Site observation of installation, especially of items that will be hidden later.
- Pre-functional checklists completed by contractors before start-up: equipment set, wired, piped and labelled.
- Start-up of equipment by the installing contractors and manufacturers.
- Testing, adjusting and balancing of air and water systems. See testing, adjusting and balancing explained.
Functional testing
Functional performance tests check that systems operate as intended through their full range: occupied and unoccupied modes, heating and cooling, economizer operation, alarms, power failure and restart, and integration with other systems such as fire alarm shutdowns and emergency power. Each test has written procedures and recorded results. Failures are logged as issues and retested once fixed.
Handover and occupancy
- Operations and maintenance manuals, as-built drawings and the final sequences of operation.
- Training for operators on each system, ideally recorded for future staff.
- A systems manual that ties everything together.
- Seasonal testing of functions that could not be tested at handover, such as cooling in a winter handover.
- A review before the end of the warranty period to catch problems while contractors are still responsible.
Who does what
| Party | Role in commissioning |
|---|---|
| Owner | Sets requirements, makes decisions on issues, provides operators for training |
| Commissioning provider | Plans and leads the process, reviews, witnesses tests, tracks issues |
| Design team | Prepares basis of design, responds to review comments, resolves design issues |
| Contractors | Install, start up, complete checklists, perform tests, fix deficiencies |
| Operators | Attend testing and training, take over the systems |
The commissioning provider should be independent of the installing contractors so that test results are reported honestly.
Bring commissioning in early. Commissioning added only at the end of construction can test systems, but it cannot fix design decisions that make a building hard to operate. The earlier it starts, the more value it adds.
What owners can do
- Write down your requirements, even briefly, before design starts.
- Put commissioning requirements in the contracts, with time in the schedule for testing.
- Insist on functional testing of controls, not just equipment start-up.
- Make sure your operators attend testing and training.
- Do not accept handover without sequences of operation, as-builts and O&M manuals.
- Schedule a check before warranties expire.
The issues log
The issues log is the working heart of commissioning. Every problem found in design review, site observation or testing is recorded with a description, the party responsible, the action required and its status. Owners should be able to see the log at any time. An issues log that closes out before handover, with the remaining items tracked to warranty, is one of the clearest signs that commissioning has done its job.
Existing buildings
Buildings that were never commissioned, or whose operation has drifted, can benefit from existing-building commissioning, sometimes called retro-commissioning. It follows a similar process: understand what the building needs, test how systems operate, fix what is wrong and train the operators. It often uncovers the same control problems described in our guide to building automation systems.
How ehZee can help
Our mechanical system inspections can support owners at handover and before warranties expire, by independently inspecting mechanical systems, reviewing documentation and checking that issues have been closed out. For whole-building handover, see our certificate of occupancy inspections.
Common questions
Is commissioning required by code?
Requirements vary. Some energy codes, green building programs and owners' standards require commissioning of certain systems. Check the codes and programs that apply to your project.
Isn't start-up by the contractor enough?
Start-up confirms that each piece of equipment runs. Commissioning confirms that the systems work together, under all modes, to meet your requirements.