Schedule MEP Commissioning Before It Delays Handover

Why does MEP commissioning always get squeezed at handover?

The last three to four weeks of a Thai residential or commercial build are dominated by visible finishes — painting, flooring, fixtures, tiling. MEP systems have been installed for weeks but testing is deferred until finishes are complete, which means commissioning ends up sharing the final days with an owner who has already booked a moving truck. Electrical circuits, water pressure, air-conditioning startup, and fire alarms all need dedicated time and undisturbed access to rooms that finishing trades are still occupying. When the commissioning window gets compressed from three weeks to four days, failures surface at the handover inspection, warranties are voided before the owner moves in, and minor items turn into month-long disputes over who is responsible for a leak found behind a finished tile. A properly scheduled commissioning phase prevents all of this.

What does an MEP commissioning sequence look like for a typical Thai build?

The correct sequence follows the physical logic of the building from infrastructure outward. Plumbing pressure testing comes first — before floor tiles are laid, so any leaking joint can be reached without removing finished surfaces. Electrical circuit testing, earthing continuity checks, and RCCB function tests run after all sockets and fittings are installed but before the utility meter connection is made. Air-conditioning commissioning follows: refrigerant charging, airflow balancing across rooms, and condensate drain testing all need a powered building and clear room access. Fire alarm testing, where the project specifies it, requires all detectors in their final position and the panel powered. An eight-unit residential compound typically needs a fifteen to twenty-one calendar-day commissioning window, not three or four days, and that window must be planned before the schedule is finalised.

How do you add MEP commissioning tasks to the Gantt planning view?

In SiteBoard's Gantt planning view, create a dedicated task for each major commissioning activity: plumbing pressure test, electrical circuit test and RCCB check, A/C commissioning, and final MEP walkthrough. Position the plumbing task to overlap with the last week of floor rough-in — its purpose is to test before tiles seal the pipes, so it must be placed earlier in the sequence, not after. Set the electrical test to finish at least five working days before the handover milestone. Give A/C commissioning its own duration row rather than combining it with the installation task; a four-to-six-unit building typically needs three to five days for proper balancing. When each task has its own row and duration, any slip in commissioning shows up as a cascade risk on the handover date — the earliest point where it can still be addressed before the owner arrives.

How much advance notice does an MEP subcontractor need for a commissioning visit?

Most MEP subcontractors in Thailand require at least three working days notice for a residential commissioning visit and five days for commercial jobs involving fire systems, generator load tests, or lift commissioning. A common mistake is treating commissioning as something the MEP contractor will handle spontaneously once finishes are done. In practice, the subcontractor has multiple sites and needs a confirmed date, a confirmed power-on or water-live status, and a clear scope for that day. Book commissioning visits the same way structural inspection hold points are booked: as a task in the Gantt with a lead-time duration that makes the booking date visible as a dependency. When this is not done, nobody calls the MEP contractor until one week before handover, and the first available slot is after the owner walk.

A real example: plumbing test before tiles saves a townhouse project

A contractor in Pathum Thani building twelve townhouses in a single compound had always run the plumbing pressure test after finishes were complete. On one project this meant the test ran after floor tiles were laid in nine of the twelve units. Three units showed a slow pressure drop. The MEP contractor traced two leaking joints, both under already-tiled floors. Repair and re-tiling cost 28,000 baht and delayed three units' handover by eleven days. On the next project, the contractor added a mandatory plumbing pressure test as a task in SiteBoard's Gantt planning view, placed the day after rough-in was complete and before any tiling began. The test flagged one joint and took two hours to fix at zero material cost. Creating the task at the kick-off meeting took five minutes.

What should the owner see on the owner sharing link during commissioning?

Most owners see the building as finished or unfinished — a status they hear in a phone call. The owner sharing link in SiteBoard gives you something more precise: a live schedule showing each commissioning task and its current completion status. When the plumbing pressure test passes, mark it 100% complete. When A/C balancing is in progress, it shows at 50%. The owner watching the schedule sees each system verified and signed off in sequence, which builds confidence ahead of the formal handover inspection. Owners who have followed the commissioning phase on the schedule arrive at the handover walk with far fewer first-day surprises, because they have already seen each system tick from in-progress to complete. The walk becomes a confirmation rather than a discovery, and the conversation stays professional throughout.

What happens when a commissioning test fails?

When a system fails its test — a pressure drop, a tripping circuit, a refrigerant leak — the correction and re-test adds days to the schedule. Treat this exactly as a structural re-inspection failure: correct the defect, rebook the test with the required lead time, and update the Gantt immediately so all downstream tasks cascade to honest dates. Log the failure, the correction work, and the re-test booking as on-site progress updates in SiteBoard. If the failure is the MEP subcontractor's responsibility, the dated log is your record for back-charging re-test costs or negotiating retention release. Update the owner sharing link the same day so the revised handover date reaches the owner directly, before a panic call creates a dispute. A test failure caught and corrected during the commissioning window costs one to three days. The same failure discovered at the owner walk costs weeks.

FAQ: Which MEP systems require third-party sign-off in Thailand?

For most Thai residential and light commercial projects, in-house testing by the MEP contractor is sufficient for plumbing, electrical circuits, and air-conditioning. However, systems connected to public infrastructure require a separate step. The electrical installation must pass an inspection by the Provincial Electricity Authority or Metropolitan Electricity Authority before the meter is connected — this is separate from the contractor's own circuit test and typically takes five to ten working days to schedule. Fire protection systems in buildings required to have them under the Building Control Act need certification from an authorised inspector. Lifts require a Department of Labour Protection and Welfare certificate before first use. Each of these external approvals belongs as its own task in the Gantt, clearly distinguished from the internal MEP commissioning test that precedes it.

FAQ: How do you commission MEP in a building that is already partially occupied?

Phased handovers and early owner occupation are common in Thai commercial projects and sometimes in residential compounds. The safest method is to commission each zone as a separate Gantt task, with power isolation and water shutdowns documented in each task note rather than assumed. Send written notice — a LINE message is sufficient — to any occupied unit at least 48 hours before a service interruption test. Write this requirement directly into the task note so no foreman runs a test without clearing it first. Log each notice sent and each commissioning result as an on-site progress update in SiteBoard. When a dispute arises about a service disruption, the dated update showing when the test ran and the notice that preceded it resolves the argument in minutes rather than a drawn-out exchange of conflicting recollections.

FAQ: Should commissioning come before or after the snagging walk with the owner?

Commissioning must be fully complete before the formal snagging walk. The snagging walk is the owner's inspection of defects; if MEP systems have not yet been tested, any failure found during the walk is added to the punch-list alongside cosmetic defects, mixing two corrective processes with different responsible parties and different repair timelines. The correct sequence is: commissioning complete and signed off by the MEP contractor, then snagging walk, then the defects liability period starts. In SiteBoard's Gantt planning view, add a milestone for MEP commissioning sign-off and set the snagging-walk milestone as dependent on it. This single dependency makes it structurally impossible to schedule the owner walk before all systems are running, preventing the most expensive handover argument: the owner claims a system never worked, and the contractor says it only needs commissioning.