What is 'post-occupancy verification'?

• A. It refers to initial commissioning before occupancy.
• B. It measures energy usage after occupancy.
• C. It verifies IAQ performance during construction.
• D. It verifies IAQ performance after building occupancy to confirm targets are met.

Answer: (D)

Post-occupancy verification is the process of checking, after the building is in use, that the IAQ performance actually meets the targets established for occupancy. It looks at how the ventilation, filtration, and control systems operate under real conditions—with actual occupants, schedules, and outdoor conditions—rather than just how they were designed or tested during construction. In practice, it involves collecting measurements of IAQ-related indicators (such as outdoor air delivery, CO2 levels, temperature and humidity, and particulate or VOC levels as applicable) and comparing them to the project’s targets. If gaps are found, adjustments are made to controls, balancing, filtration, or ventilation rates to bring performance in line with the goals, and the results are documented. This distinguishes it from activities done before occupancy (initial commissioning) or targets focused on energy use or construction-phase IAQ checks, which do not verify performance in actual occupied operation.