This is a legacy version of the WELL Building Standard. Please check the latest version here.

Air quality standards

Air quality standards


To ensure a basic level of high indoor air quality.

Yes, radon testing is required on the ground floor (or below ground floor), if the floors are included in the project scope and if they are regularly occupied.

GBCI will use data from air quality measurements near the project and take 30% of the average value. For example, if the ambient PM2.5 levels average 90 µg/m³ on the day of Performance Verification, the project will use 27 µg/m³ as the threshold for Part 2c. Note that projects using this approach are limited to Silver certification level.