A building services package is not finished when the last cable is terminated. It is finished when every system has been proved to do what the design says, in front of the person the contract names, with a record that says so. The commissioning plan is the document that gets a contractor from the first to the second, and the ones that fail do so because they describe commissioning as a single event rather than the five stages it actually is. This is how we structure a plan so that each stage has an entry condition, an owner, a witness and a record.
Five stages, not one
The words move around between specifications, and the first job of the plan is to define them for the project. We use five: static completion, pre-commissioning, commissioning, witnessing and seasonal or proving commissioning. CIBSE Commissioning Code M (2022) is the reference for how the whole process is managed, and BSRIA BG 8/2009 gives the model plan; between them they settle the structure of the document. What they cannot settle is the sequence on a particular job, because that is fixed by dependency. No fan runs before the ductwork leakage test and the fire damper drop tests; no pump runs before the pressure test and the water quality certificate; no board is energised before initial verification. The plan sets the stages out as a table of activities, each with what it depends on, the ITP or form that releases it, the planned date and the witness required. A programme bar chart with a paragraph underneath does not do that, and a client's consultant will say so at the first witness visit.
Stage 1: static completion
Static completion means the installation is physically finished and its static tests have been passed. For pipework that is the pressure test to the value and duration in the specification; for ductwork the leakage test to the class specified, with the record to BS EN 12599:2012 or the specification's own method; for the electrical installation the dead tests of initial verification under BS 7671:2018+A4:2026 with the schedule of test results filled in. The entry condition for everything that follows is that the installation ITPs for the system are signed, including the hold points that were witnessed when the work was still visible: the containment before the ceiling closed, the insulation before the cladding went on, the pipework before the screed. A commissioning plan that starts at the pumps has skipped the stage that decides whether the pumps can run.
Stage 2: pre-commissioning
Pre-commissioning is the set of checks that prove a system is clean, safe and ready to start. For heating and chilled water it is the pre-commission cleaning to BSRIA BG 29/2021, with the flushing velocities, the water samples and the laboratory results on file before any circulating pump runs for balancing. For air systems it is the checklist route in BSRIA BG 49/2024: plant secured, filters fitted, dampers free and marked, drives aligned, rotation checked at a bump start. For the electrical installation it is the Electrical Installation Certificate and its schedules for every board that feeds the system; nothing is energised on a verbal assurance. The plan also lists the instruments here, with serial numbers, calibration due dates and the register reference, because a balancing result from an instrument that was out of calibration is a result the client is entitled to reject. Permits, isolations, commissioning method statements and task briefings sit in this stage too, and a reviewer will look for them.
Stage 3: commissioning
Commissioning proper is setting each system to work and adjusting it to the design values. The acceptance basis is well established and the plan cites it at the current edition: air distribution to CIBSE Commissioning Code A (2024) and BSRIA BG 49/2024; water distribution to CIBSE Commissioning Code W (2025), which replaced the 2010 edition, with BSRIA BG 2/2010 alongside it; heating systems to BS EN 14336:2025; controls to CIBSE Commissioning Code C (2001); fire detection and alarm to BS 5839-1:2025; emergency lighting to BS 5266-1:2025. The tolerances themselves are project values. A specification that asks for terminal flow rates within a stated percentage of design has set the acceptance criterion, and the plan says so rather than quoting a guide that may say something different. The record form for each test carries the design value, the tolerance and the measured value on the same line, so that pass or fail is decided on the sheet and not argued afterwards.
Stage 4: witnessing, and who witnesses what
Witnessing is where most disputes start, because the plan did not say who was expected, at what notice, and what happened if they did not come. The four levels are the same as on any ITP. A hold point stops work until the named party has attended and signed. A witness point invites the named party and proceeds after the notice period, usually 24 or 48 hours under the contract, if they do not attend, with the non-attendance recorded. Surveillance is unannounced. Review is the document only. The plan states the level for each test, and the pattern on most commercial projects looks like this.
| Test | Typical witness | Level |
|---|---|---|
| Pressure tests, ductwork leakage, flushing samples | Principal contractor's quality team; client's clerk of works where appointed | Witness |
| Initial verification and energisation of each board | Principal contractor; client's electrical engineer on a sample | Hold for energisation, review of certificates |
| Air and water balancing | Client's services consultant, on a sample of terminals and branches | Witness |
| BMS point-to-point and control loops | Client's consultant; the facilities team | Review, with a witnessed sample |
| Fire alarm cause-and-effect and the integrated systems test | Client, fire engineer, building control body, often the insurer | Hold |
The contract governs, and the plan should say where it departs from that pattern. What it must not do is mark every line as a hold point for every party. That is not a plan; it is a way of never getting the consultant to site. The witness notice and the witness test record are one form in our packs so that the notice, the attendance and the result sit on the same page.
Stage 5: seasonal and proving commissioning
A heating system commissioned in July has not been proved at design conditions, and a chiller commissioned in January has not either. The plan says which systems are deferred to seasonal commissioning, the month it will happen, who attends and what record is produced, and it says so before practical completion so that the retention and the defects period take account of it. Proving runs for the BMS, the sequence of operation under real load, and the repeat of any test that the client's consultant witnessed only as a sample belong here too. If the plan is silent, the client will assume the systems were fully proved at handover and the first cold week will be a defect notice.
The records that close a system
A system is closed when the following exist, are signed by the person who did the work, and are indexed against the ITP line: the installation ITPs and check sheets; the static test certificates; the pre-commissioning checklists and the water quality results; the Electrical Installation Certificate and schedules; the balancing records with design, tolerance and measured values; the controls point-to-point and loop tuning records; the fire alarm commissioning certificate and cause-and-effect record; the emergency lighting test records; the witness notices and the witnessed results; the nonconformity reports and their close-out; and the training record and the O&M content to BSRIA BG 79/2020. The plan lists every one of those record types in a table with the form, who produces it, who reviews it and where it is filed. If a record is not on that table, it will not be produced, and the gap will be found at handover.
Our Commissioning & Test Plan Pack is built on this structure: a plan template to Code M and BG 8 with a completed worked example, eight commissioning ITPs and eleven test records with the limits printed on the sheet. The Commissioning Check Sheet Library carries the same lines onto printable sheets for the engineers doing the tests. The free ITP for LV distribution boards shows the same pattern before you buy anything.
Where this leaves you
The Commissioning & Test Plan Pack is the plan template to CIBSE Code M and BSRIA BG 8 with a completed worked example, eight commissioning ITPs and eleven test records with the limits on the sheet; the Commissioning Check Sheet Library puts the same lines on printable sheets. Download the free ITP first to see how a commissioning line is written.
Written by Craig Collier, MCIOB, CQP MCQI, MAPM, Director of StructAssure Ltd. Published 23 July 2026; standards and regulations as read on that date.