WELL v2 air features, met with continuous sensor data
The WELL Building Standard, from IWBI, certifies buildings on health and wellbeing. Its Air concept sets limits for particulates, gases and CO2, and accepts continuous sensor data as evidence for several features. Aqueduct supplies those readings per zone through aQ AirSafe.
Who it applies to
Owners and tenants pursuing WELL v2 certification or the WELL Performance Rating. The current version is WELL v2, Q2 2025. The Air concept has four preconditions, A01 to A04, which every project must meet, and optimizations A05 to A14 that earn points.
A01 requires air parameters to be measured at least once a year and the results submitted annually, so the evidence does not end at certification.
Features that need measured data
Feature codes and thresholds from WELL v2, Q2 2025. IWBI and its performance testing agents decide certification.
| Requirement | What it asks for | Data Aqueduct supplies |
|---|---|---|
| A01 Air Quality (precondition) | PM2.5 at most 15 µg/m3, PM10 50, TVOC 500 µg/m3 by sensor, CO 9 ppm, ozone 51 ppb; by performance test or sensor data. | Continuous PM2.5, PM10, TVOC, CO and ozone per zone. |
| A03 Ventilation Design (precondition) | Design to ASHRAE 62.1, or monitoring that keeps CO2 at 900 ppm or 500 above outdoors. | CO2 per zone against outdoor CO2. |
| A05 Enhanced Air Quality | Tighter limits, such as PM2.5 at 12 or 10 µg/m3 and NO2 at 21 ppb. | The same sensors, judged against the stricter thresholds. |
| A06 Enhanced Ventilation Design | DCV holding CO2 under 900 or 750 ppm in nearly all regularly occupied spaces. | CO2 compliance per space, as a share of occupied hours. |
| A08 Air Quality Monitoring and Awareness | Monitors for at least three parameters, calibrated every three years, with occupant displays updated every 15 minutes. | Sensor register with calibration dates and live data for displays. |
Thresholds
The stricter A06 CO2 tier, or 350 ppm above outdoor air.
Source: WELL v2 A06A01 PM2.5 limit where outdoor PM2.5 is at or above 35 µg/m3.
Source: WELL v2 A01Related standards
sites in 21 countries run on Aqueduct.
and 9 clinics in one of India’s top hospital chains.
US airport running water intelligence on Aqueduct.
of commercial real estate under Aqueduct.
FMCG manufacturing campus.
operations run on Aqueduct.
Related
Common questions
For A01 Air Quality, yes: the feature accepts either a performance test or continuous sensor data. Sensors must meet IWBI specifications for accuracy and placement, and your WELL AP confirms which route the project uses. aQ AirSafe sensors can supply that data per zone.
One display per 500 m2 (5,400 sq ft) of regularly occupied space, mounted between 1.1 and 1.7 m. Aqueduct keeps the register of those monitors with their calibration dates, so the evidence for A08 is ready at recertification.
Ongoing data. A01 asks for air parameters to be measured at least yearly and submitted, so a continuous sensor record avoids a separate annual test campaign. Aqueduct exports the year of readings per zone for submission to IWBI.
Yes, through its ventilation features. A03 can be met by monitoring that holds CO2 at 900 ppm, or 500 ppm above outdoor air, and A06 earns points for lower levels across occupied spaces. aQ AirSafe reports how many occupied hours each space stayed under its level. See CO2 monitoring.
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