Compliance · US Green Building Council
LEED v5: Indoor Air Quality Performance (Operations and Maintenance)
Indoor: green building certification (LEED v5 O+M)
LEED v5, released by the US Green Building Council in 2025, rewards measured indoor air quality. In the Operations and Maintenance (O+M) rating system, the Indoor Air Quality Performance credit gives up to 10 points. Its continuous-monitoring option measures CO₂, PM2.5, and TVOC for at least three consecutive months (hourly, and every 15 minutes for CO₂) and awards points for results within its limits. CO₂ at or below 1,000 ppm (95th percentile) earns 3 points, and at or below 800 ppm earns 4. PM2.5 at or below 15 µg/m³ (daily average) earns 3 points, and at or below 12 µg/m³ earns 4. Monitoring TVOC earns 2 points at any level.
The standard
What LEED V5 Sets for Indoor Air
Its one-time testing option sets limits of 9 ppm for carbon monoxide (and no more than 2 ppm above outdoor), 50 µg/m³ for PM10, 12 µg/m³ for PM2.5, 0.07 ppm for ozone, 21 ppb for nitrogen dioxide, and 16 ppb for formaldehyde, with TVOC above 500 µg/m³ calling for investigation.
Limit values
LEED v5 Limit Values
Every value US Green Building Council publishes for the 8 parameters below, with its averaging period, as the standard states it.
Who it applies to
Who Uses It
Owners and operators certifying existing buildings under LEED v5 O+M, and new construction projects under LEED v5 BD+C. BD+C projects demonstrate air quality through pre-occupancy testing or permanently installed sensors, rather than the flush-out that earlier versions allowed.
Monitoring
How Monitoring Demonstrates Compliance
For the continuous option, the record is the monitoring data itself: at least three months within the reporting period, from monitors that are building grade or better, with CO₂ as the 95th percentile and PM2.5 and TVOC as daily averages. The same continuous record can support WELL v2 and ESG reporting. The configurator assembles a monitor for CO₂, PM2.5, and TVOC.
Recommended
best match-
Industrial monitor for indoor and outdoor sites. Built-in sensors cover the essentials, and hot-swappable gas sensor cartridges and a differential-pressure option add more.
Built-inPM10PM2.5Gas 1
Aethair MultiGas+
Carbon Monoxide (CO)VOC (Total)Metal-oxide semiconductor (MOS) sensing tracks carbon monoxide, methane, and total VOC from a compact…
Gas 2
Aethair O₃+NO₂
Nitrogen Dioxide (NO₂)Ozone (O₃)Four-electrode electrochemical sensing measures oxidizing gases (ozone plus nitrogen dioxide) and reports one…
MultiSense
Custom MultiSense built to order
Carbon Dioxide (CO₂)Formaldehyde (CH₂O)Built to order for the MultiSense socket with the Aethair CO₂ (dual NDIR) cartridge's sensor (0-5000 ppm, 1 ppm resolution) and the Aethair MultiSense cartridge's sensor (0-10 ppm, 10 ppb resolution).
Expansion
Free: differential pressure
Also measures 12 more
Dew PointHeat IndexRelative HumidityIlluminance / LightParticle Count (by size)PM1Total PM / Mass Conc.Barometric PressureEquivalent Continuous Level (Leq)Sound Pressure Level (SPL)Air TemperatureMethane (CH₄)
Who measures each parameter
| Parameter | Aethair PRO |  Aethair IAQ |  External |
|---|---|---|---|
| Carbon Dioxide (CO₂) | CO₂ (dual NDIR), CO₂ (self-calibrating NDIR) cartridges | Built in | 2 instruments via Thiamis |
| PM2.5 | Built in | Built in | 3 instruments via Thiamis |
| PM10 | Built in | Built in | 3 instruments via Thiamis |
| Carbon Monoxide (CO) | CO (electrochemical), MultiGas+ +1 cartridges | — | 3 instruments via Thiamis |
| Ozone (O₃) | O₃+NO₂ cartridge | — | 1 instrument via Thiamis |
| Nitrogen Dioxide (NO₂) | NO₂, MultiSense +1 cartridges | — | 1 instrument via Thiamis |
| Formaldehyde (CH₂O) | MultiSense cartridge | Built in | — |
| VOC (Total) | VOC (ppm PID), VOC (ppb PID) +2 cartridges | Built in | 2 instruments via Thiamis |
Devices
Devices That Cover LEED v5
How much of this standard one Aethair monitor covers, followed by the third-party instruments in the sensor catalog that measure its parameters. Each connects to Environet through a Thiamis gateway, which adds whatever the monitor leaves out.
Aethair monitors
Aethair PRO Built in + Aethair MultiGas+, Aethair O₃+NO₂, Custom MultiSense (CO₂, CH₂O)Covers all 8Aethair IAQ Built-in sensors5 of 8: CO₂, PM2.5, PM10, CH₂O, VOCCovers part of it (combine on one Thiamis)
RAE Gas Detectors4 of 8: CO, CO₂, NO₂, VOC
TSI DustTrak Particulate & Dust Monitors2 of 8: PM10, PM2.5
Met One E-BAM Particulate & Dust Monitors2 of 8: PM10, PM2.5
Particles Plus Particulate & Dust Monitors2 of 8: CO₂, VOC
Trolex Particulate & Dust Monitors2 of 8: PM10, PM2.5
TSI GM460 Gas Detectors1 of 8: CO
RKI Instruments GX6000 Gas Detectors1 of 8: CO
2B Technologies POM Specialty Air Analyzers1 of 8: O₃Solutions
Solutions Judged Against LEED v5
Indoor Air Quality
Offices, schools, homes, and public buildings
Article Library
Articles on LEED v5
How Building Certifications Use Air Quality Monitoring
How WELL and LEED v5 incorporate air quality monitoring, why both frameworks are moving toward continuous performance, and what that means for building teams.
Commercial Building IAQ Monitoring: ASHRAE 62.1 & WELL
Indoor air quality monitoring for commercial buildings: what to measure, which standards apply, and how property managers build a program tenants trust.
WELL Building Standard Air Quality: CO2 & PM2.5 Limits 2026
WELL v2 air quality limits: PM2.5 at 15 µg/m³, formaldehyde at 50 µg/m³, CO2 at 900 ppm for ventilation monitoring, plus the monitoring WELL verifies.
OSHA Air Quality Standards 2026: PELs & 29 CFR 1910.1000
OSHA air quality standards for indoor and outdoor work: permissible exposure limits, Table Z-1, 29 CFR 1910.1000, and the heat and wildfire smoke triggers.
IAQ Monitoring Parameters: PM2.5, CO2, VOCs & Formaldehyde
Indoor air quality monitoring parameters explained: PM2.5, CO2, VOCs, and formaldehyde, plus the sensors, thresholds, and OSHA, ASHRAE 62.1, and WELL limits.
Questions
LEED v5 FAQ
How many LEED v5 points does continuous air monitoring earn?
Up to 10 in the O+M Indoor Air Quality Performance credit: points for monitoring CO₂, PM2.5, and TVOC, and more for CO₂ at or below 1,000 or 800 ppm and PM2.5 at or below 15 or 12 µg/m³.
What LEED v5 limit applies to CO₂?
The 95th percentile of continuous readings at or below 1,000 ppm earns 3 points and at or below 800 ppm earns 4.
What does LEED v5 require for one-time air testing?
Limits including 9 ppm for carbon monoxide, 50 µg/m³ for PM10, 12 µg/m³ for PM2.5, 0.07 ppm for ozone, 21 ppb for nitrogen dioxide, and 16 ppb for formaldehyde.
Monitor Against LEED v5
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