Commissioning And The First Months Of Occupancy

A building is handed over in a working condition and reaches its real operating condition some months later.

That gap is normal, it is predictable, and it is where the difference between a building that performs and one that merely complies gets decided.

Commissioning is a proof, not a switch-on

Commissioning means demonstrating that each system does what it was designed to do, under the conditions it will face, with the result recorded.

Which is different from turning it on and confirming it runs.

**Mechanical.** Airflow measured rather than assumed, extraction rates at the fan and at the grille, controls operating in the sequence intended, and the heating and cooling achieving the design condition.

**Electrical.** Circuits tested and recorded, safety devices operating, every outlet and fitting proven, and the switchboard labelled to match reality rather than to match the drawing.

**Hydraulic.** Pressures and flows at the outlets, hot water delivery temperatures at the fixtures, tempering valves set and recorded, and drainage proven to fall and discharge.

**Fire and life safety,** tested as a system, with the certificates issued.

**Specialist equipment,** including any hoist, which is load tested and certified rather than inspected. The structural provision behind it is in [ceiling hoists and structural provision](/blog/ceiling-hoists-and-structural-provision).

In factory delivery much of this happens before the module leaves, which is one of the advantages: a system installed and tested indoors is more likely to be right. What remains on site is the testing of the connections and of anything that crosses between modules, plus the whole-building performance.

Record the settings

The part that is almost always skipped, and the one that saves the most later.

Every adjustable thing has a setting: control setpoints, timer durations, tempering valve temperatures, fan speeds, lighting sensor delays, hot water thermostat positions.

Those get written down at commissioning. Without the record, the first time somebody adjusts a setting there is no way back to the commissioned condition, and a building drifts into whatever configuration successive adjustments produce. The record belongs in the handover pack described in [handover documentation and as-built records](/blog/handover-documentation-and-as-built-records).

Why the first months matter

A building in use behaves differently from a building being tested.

Occupants use it in ways nobody modelled. Ventilation that was adequate on test is marginal when four people are home all day. A heating setpoint that suited the design condition is wrong for the people living there. A sensor delay that seemed right leaves a corridor dark at the wrong moment.

In supported accommodation this is more pronounced, because the resident's routine and the support worker's routine are specific and were not fully knowable at design stage.

Which means the first months are a tuning period, and treating them as such produces a better building than treating handover as the end.

What to review, and when

**At four to six weeks.** How the building is actually being used, what the occupants and support staff have found awkward, and any system behaving unexpectedly. Most of what comes out of this is adjustment rather than defect.

**After the first full heating season and the first full cooling season.** The only time thermal performance can really be assessed. Comfort, condensation, running cost and whether the system is sized and controlled correctly. Issues here are rarely faults and usually settings, and they connect back to [energy and thermal performance in modular](/blog/energy-and-thermal-performance-in-modular).

**At the end of the defects liability period,** which is a formal inspection against the contract rather than a conversation, and is covered in [defects and warranty in modular delivery](/blog/defects-and-warranty-in-modular-delivery).

The things that show up in the first year

Predictable, and mostly minor.

Doors and hardware needing adjustment as the building settles. Shrinkage cracking at junctions, which is movement rather than failure. A control setting that does not suit the routine. Drainage that is slow because of how a fixture is used. A sensor or timer in the wrong position for the occupants.

None of that indicates a problem with the build. All of it is better fixed in the first year, while the defects period is open and while somebody is paying attention.

Start the maintenance clock

The first scheduled maintenance items fall due during this period, and whether they are done is what determines whether warranties stay valid and whether the whole-of-life numbers hold.

Which is why the maintenance schedule is handed over with dates already calculated, not with intervals that somebody has to convert. The reasoning is in [maintenance and whole-of-life costs](/blog/maintenance-and-whole-of-life-costs).

Who needs to be trained

The people operating the building, not the people who commissioned it.

In supported accommodation that means support workers who rotate, which means the training is a document and a short walkthrough rather than a single handover briefing to one person. A building with systems nobody present knows how to operate will be operated badly regardless of how well it was commissioned.

How we deliver.

MADEmodular / MADEbetter.