Pre and Post-Occupancy Air Quality Testing

Pre-occupancy testing after completion

Testing is planned after the relevant finishes, furniture and final clean are complete and the ventilation is operating in the agreed mode. Typical parameters include formaldehyde, TVOC and particulates, selected against the handover specification or registered scheme criteria. Formaldehyde and scheme-critical VOC evidence uses the required laboratory sampling route; direct-reading TVOC can support screening but is not substituted for a specified analytical method. Room conditions, product completion dates and ventilation history are recorded with every sample.

Readiness before instruments are placed

Testing too early can describe active works rather than the completed space. We review readiness with the project team and link to the detailed IAQ Compliance checklist where formal criteria apply.

• Fit-out, snagging that affects air quality and furniture installation complete
• Final clean completed with products and date recorded
• Ventilation commissioned and operating in the required condition
• Windows, doors and room status agreed
• Material and product information available
• Representative locations shown on current drawings

Flush-out and retest route

If a result is elevated or the space was not ready, the report identifies the relevant evidence and possible sources. The project team may remove a source, complete further cleaning or operate a managed ventilation flush-out with its HVAC specialist. We then agree when conditions are stable enough for repeat sampling. Retesting uses the required method and records the new room state, allowing the handover file to preserve both the original result and the evidence after action.

Post-occupancy testing under normal use

Once the space is in routine use, testing can add CO₂, comfort parameters, particulates and VOC monitoring selected for the occupied question. Real-time logging shows meeting-room peaks, daily accumulation and the effect of normal ventilation schedules. Laboratory sampling is repeated only where a criterion or earlier finding warrants it. Results are compared carefully because occupancy, season, cleaning and furniture loading may differ from the pre-occupancy stage. The purpose is to understand operational performance, not force unlike conditions into a simple before-and-after score.

Handover documentation

The final record identifies the project stage, readiness checks, methods, sample locations, ventilation condition, results, limitations and any retest. Drawings and room references let landlords and occupiers trace the evidence after the project team leaves. Where BREEAM or WELL criteria apply, testing follows the registered framework and the appointed assessor uses the evidence for the project decision. For an existing building with no handover event, a Baseline Air Quality Survey is the more suitable route.