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Pillar
Tier
Project

Pillar 2

Indoor Air Quality & Health

Keep occupants safe from combustion gases, radon, mold, and indoor pollutants. Covers gas/CO testing, MERV filtration, radon mitigation, kitchen/bath exhaust, and humidity control.

16 requirements · 2 badges

Requirements

Grouped by the tier at which they first become mandatory. Tap any row to slide in the full detail.

Certified (8)

  • HVAC Filter Rating

    Minimum MERV rating for filters on ducted heating/cooling systems.

    Open

  • Bathroom Exhaust Ventilation

    Bath fans exhaust to the outdoors (verified with a toilet-paper test). Silver and above must also test to ≥ 50 CFM per bathroom.

    Open

  • Range Hood Tested at 100 CFM (or Electric Stove)

    Either install an electric stove, or have a range hood that is tested to vent at least 100 CFM to the outdoors.

    Open

  • Gas Leak Inspection

    All gas appliances and piping inspected for leaks. No leaks permitted; repair or replace before certification.

    Open

  • Carbon Monoxide Testing of Combustion Appliances

    CO leak test performed on all combustion-based appliances. Repair or replace any appliance that fails.

    Open

  • Carbon Monoxide Detectors

    Hardwired CO detectors installed on every floor and near any fireplace.

    Open

  • Radon Testing and Mitigation

    Test for radon; no levels above PCL 4 permitted. Install a passive or active mitigation system if needed. All new construction and all EPA Zone 1 homes require a system.

    Open

  • Fireplace Safety

    If a combustion fireplace exists: seal, vent, provide makeup air, and install a CO detector. (At Platinum, no combustion fireplaces indoors — electric only.)

    Open

Silver (3)

  • Whole-House Fresh Air Supply

    A whole-house mechanical fresh-air supply system is provided.

    Open

  • Sealed/Vented New Gas Appliances

    Any new gas appliances are sealed-combustion / vented to the outdoors — or the project goes all-electric.

    Open

  • Kitchen Ventilation

    Kitchen has proper ventilation via range hood, outdoor air system, or air-quality monitor. (At Platinum, the range hood must detect PM2.5 and activate automatically.)

    Open

Gold (2)

  • Balanced Fresh-Air System

    A balanced (supply + exhaust) fresh-air system is installed and tested.

    Open

  • Indoor Air Quality Sensor

    RESET-certified air-quality sensor installed in the main living area or ducts. (At Platinum, sensor measures CO₂, TVOC, humidity, temp, and PM2.5.)

    Open

Platinum (3)

  • Ventilation with Heat/Energy Recovery or Smart Controls

    Ventilation includes energy-recovery / heat-recovery (ERV/HRV) or smart-control features.

    Open

  • Whole-Home Humidity Control

    Whole-home dehumidification / humidification provided where appropriate by climate (target 40–50°F dewpoint).

    Open

  • No Indoor Combustion Fireplace

    No combustion fireplaces present indoors. Electric fireplaces permitted.

    Open

Badges in this pillar

  • Healthier Home (Clean Living)

    Project goes beyond baseline IAQ requirements with low-emission materials, advanced filtration, and active monitoring.

    Open

  • Reduced Electromagnetic Frequency (EMF)

    Wiring, lighting, and wireless infrastructure designed to minimize EMF exposure for occupants.

    Open
Indoor Air Quality & Health Required from Certified

HVAC Filter Rating

Minimum MERV rating for filters on ducted heating/cooling systems.

Spec by tier

TierSpec
CertifiedMERV 8 minimum
SilverMERV 10 minimum
GoldMERV 13 minimum
PlatinumMERV 16 minimum

Scope

All HVAC return-air filters in ducted heating, cooling, and ventilation systems serving the dwelling.

Requirements

Performance targets

  1. 01.

    Filter MERV rating must meet the tier threshold in the "Spec by tier" table above.

  2. 02.

    The HVAC system's static pressure must be verified to support the filter MERV without restricting airflow — higher MERV filters create more pressure drop. Increase filter surface area (deeper filters: 4" or 5" pleated) where needed to stay within manufacturer spec.

  3. 03.

    Filter change cadence must be documented in the maintenance instructions (typically every 3-6 months).

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Filter spec sheets (or photos of the rated labels) for all installed return-air filters.

  2. 02.

    HVAC static pressure test record showing total external static pressure within manufacturer spec at design airflow.

Guidance

Why MERV ratings matter — and what they actually filter

MERV 8 captures dust, mold spores, pet dander. MERV 11-13 captures pollen, smoke particles, and most allergens. MERV 16 captures bacteria, ultrafine particles, virus carriers — approaching HEPA performance. Each step up roughly doubles the particle-capture efficiency for the next-smaller particle size.

Note

Many residential HVAC systems can't handle a MERV 13+ filter at standard 1" depth — the pressure drop exceeds the blower's capacity and reduces airflow below cooling spec. Solution: switch to a 4-5" deep pleated filter (Aprilaire, Honeywell, etc.) — same MERV rating, much larger surface area, no airflow penalty.

Resources

  • ASHRAE 52.2 — Method of Testing General Ventilation Air-Cleaning Devices

    The standard that defines MERV ratings.

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Indoor Air Quality & Health Required from Certified

Bathroom Exhaust Ventilation

Bath fans exhaust to the outdoors (verified with a toilet-paper test). Silver and above must also test to ≥ 50 CFM per bathroom.

Scope

Exhaust fans in every bathroom — full bath, half-bath, and powder rooms with a permanent water source.

Requirements

  1. 01.

    Every bathroom must have an exhaust fan that vents to the outdoors. Termination must be an exterior wall, soffit (where vented), or roof — NOT into the attic, eave, or wall cavity.

  2. 02.

    At Certified: verify with a "toilet paper test" — hold a single ply of TP against the running fan and confirm it sticks.

  3. 03.

    At Silver and above: flow-test the fan to confirm at least 50 CFM (per ASHRAE 62.2 minimum).

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Photo of each bath fan termination (exterior wall hood, roof jack, or vented soffit).

  2. 02.

    For Silver+: flow-test record (date, fan model, measured CFM at the grille).

Guidance

Why termination matters

A surprisingly large fraction of installed bath fans terminate inside the attic — the installer ran the duct but never finished it through the roof. Result: humid air dumps directly into the attic, condenses on the underside of the roof deck, and causes mold, ice damming, or even structural rot. The toilet-paper test verifies the fan moves air; visual inspection of the termination verifies that air goes outside.

Note

Common failure: rigid metal duct connected to a flex bath-fan inlet, with the connection unsealed by tape. Air leaks out at the joint and into the attic. Mastic the joint with HVAC tape (UL-181 rated) and you fix it permanently.

Resources

  • ASHRAE 62.2 — Ventilation for Acceptable Indoor Air Quality in Residential Buildings

    The bath-fan CFM minimum (50 CFM intermittent or 20 CFM continuous) comes from this standard.

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Indoor Air Quality & Health Required from Certified

Range Hood Tested at 100 CFM (or Electric Stove)

Either install an electric stove, or have a range hood that is tested to vent at least 100 CFM to the outdoors.

Scope

The kitchen cooking surface. Choose one of the two compliance paths — electric stove (eliminates combustion) or vented range hood (removes combustion products if gas is used).

Requirements

Choose one path

  1. 01.

    Electric path: install an electric stove (induction or resistance). No range hood requirement applies. (Aligns with the Gold all-electric cooking requirement.)

  2. 02.

    Vented hood path: install a range hood ducted to the outdoors and tested at ≥ 100 CFM at the hood face.

  3. 03.

    The hood capture area must extend at least to the front edge of the cooktop burners (not just over the rear burners).

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Photo of the installed cooktop showing whether it is electric or gas.

  2. 02.

    For vented hood: spec sheet showing rated CFM + flow test record at the hood face.

  3. 03.

    Photo of the hood termination outdoors.

Guidance

Why this is a single-requirement two-path setup

Gas combustion releases NO2, CO, formaldehyde, and ultrafine particles at concentrations that frequently exceed EPA outdoor air-quality limits indoors. A properly-vented hood mitigates this. An electric stove sidesteps the problem entirely. The standard accepts either.

Note

Recirculating ("ductless") range hoods do not satisfy this requirement — they filter particles but do not remove NO2 or CO. The hood must vent to the outdoors.

Resources

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Indoor Air Quality & Health Required from Certified

Gas Leak Inspection

All gas appliances and piping inspected for leaks. No leaks permitted; repair or replace before certification.

Scope

All natural-gas and propane plumbing inside the dwelling — supply piping, fittings, appliance connections, and shutoff valves.

Requirements

  1. 01.

    A licensed plumber or gas-fitter must perform a leak-detection test on the entire gas system (typically a pressure-drop test with a manometer).

  2. 02.

    Any leak — even a "soap-bubble" trace — must be repaired and retested before sign-off.

  3. 03.

    Connection fittings should be tested with electronic leak detector or soapy water at every joint.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Signed leak-test report from the licensed gas fitter, dated within the project window.

  2. 02.

    Photo of the manometer reading at start and end of the hold period (if used).

Guidance

Why even tiny leaks matter

A small natural gas leak is not just a methane release (climate impact) — it can elevate indoor NO2 and benzene exposure even when the appliance is OFF. A 2023 Stanford study found methane leaks in 80% of inspected residential kitchens, with measurable benzene downstream.

Note

After certification, occupants should be advised to call the gas utility and have an outside-the-meter sniff test done annually. Most utilities offer this for free.

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Indoor Air Quality & Health Required from Certified

Carbon Monoxide Testing of Combustion Appliances

CO leak test performed on all combustion-based appliances. Repair or replace any appliance that fails.

Scope

All combustion-based appliances in the dwelling — furnace, boiler, water heater, gas range/oven, gas dryer, and gas fireplace.

Requirements

  1. 01.

    Every combustion appliance must be tested for CO emissions at the flue, draft, and ambient air around the unit.

  2. 02.

    Tests must be performed under worst-case conditions: all exhaust fans running, doors closed (negative-pressure stress test).

  3. 03.

    Any reading above the manufacturer's maximum, or any spillage detected, requires immediate service before certification.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Combustion analysis report for each appliance: model, flue CO ppm, draft pressure, and spillage check.

  2. 02.

    List of test conditions (which exhaust fans were running during the worst-case stress test).

Guidance

Why worst-case testing matters

A furnace that vents fine on a calm day can backdraft when the kitchen hood is running. Combustion-zone depressurization is a leading cause of CO incidents in modern tight homes. The worst-case test simulates the conditions where backdrafting will happen first.

Resources

  • BPI 1100/1200 — Combustion Safety Test Standard

    The protocol most home-performance contractors use for combustion safety testing.

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Indoor Air Quality & Health Required from Certified

Carbon Monoxide Detectors

Hardwired CO detectors installed on every floor and near any fireplace.

Scope

Carbon-monoxide detection throughout the dwelling.

Requirements

  1. 01.

    Install UL-certified CO detectors on every floor of the dwelling.

  2. 02.

    Place a CO detector within 10 feet of every bedroom door.

  3. 03.

    Place a CO detector within 10 feet of every fireplace and combustion appliance.

  4. 04.

    Detectors must be hardwired with battery backup (not battery-only).

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Floor-plan markup showing CO-detector locations.

  2. 02.

    Photos of installed detectors (showing the UL listing label).

Guidance

Combination vs dedicated detectors

Combination smoke + CO detectors satisfy this requirement. Standalone CO detectors are also fine. The key is coverage per the placement rules above. Replace all detectors every 10 years (per UL 2034 sensor lifespan) — most current models have a built-in end-of-life chirp.

Note

Low-level CO detectors (sensitive to 10-30 ppm) provide a much earlier warning than standard UL-listed units, which only alarm at 70+ ppm sustained for over an hour. Not required by this standard, but recommended for households with children, pregnant occupants, or anyone with heart/respiratory issues.

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Indoor Air Quality & Health Required from Certified

Radon Testing and Mitigation

Test for radon; no levels above PCL 4 permitted. Install a passive or active mitigation system if needed. All new construction and all EPA Zone 1 homes require a system.

Scope

Indoor radon levels throughout the dwelling, with emphasis on the lowest livable floor.

Requirements

  1. 01.

    Perform a 48-hour minimum short-term radon test on the lowest livable level of the dwelling. Test must follow EPA protocol (closed-house conditions for 12 hours before + during test).

  2. 02.

    If result is ≥ 4 pCi/L, install a radon mitigation system (passive or active sub-slab depressurization) and retest to confirm post-mitigation levels.

  3. 03.

    All new construction in any climate must include a passive radon system (4" vertical riser from sub-slab to roof, capped or fan-assisted).

  4. 04.

    All homes in EPA Zone 1 counties must include an active radon system regardless of initial test results.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Radon test report from a certified lab (NRPP or NRSB), with the test conditions, dates, and result in pCi/L.

  2. 02.

    For mitigation: system design + photos showing the riser, fan (if active), and roof termination.

  3. 03.

    Post-mitigation retest report.

Guidance

Why this is a Certified-level requirement

Radon is the #2 cause of lung cancer in the U.S. after smoking — and #1 among non-smokers. The EPA estimates ~21,000 deaths/year are attributable to radon exposure. Testing costs $25-$50; mitigation costs $800-$2,500. Both are dramatically cheaper than the health consequences of unaddressed exposure.

Resources

Note

Long-term radon tests (90+ days) are more accurate than 48-hour short-term tests. GHI accepts either for compliance, but for occupied homes with marginal short-term results (3.0-3.9 pCi/L), a follow-up long-term test is recommended.

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Indoor Air Quality & Health Required from Certified

Fireplace Safety

If a combustion fireplace exists: seal, vent, provide makeup air, and install a CO detector. (At Platinum, no combustion fireplaces indoors — electric only.)

Scope

Any combustion-based fireplace (wood, gas, pellet) installed in the dwelling — both new and existing.

Requirements

  1. 01.

    The fireplace must be a sealed, vented unit. Open-hearth wood fireplaces are not permitted at any tier (they backdraft and release dangerous PM2.5).

  2. 02.

    Provide dedicated makeup air to the fireplace, sized per the manufacturer's specification.

  3. 03.

    Install a hardwired CO detector within 10 feet of the fireplace.

  4. 04.

    At Platinum: no combustion fireplace permitted indoors — electric fireplaces only.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Fireplace manufacturer spec sheet showing sealed/vented design and makeup-air requirement.

  2. 02.

    Photo of the installed makeup-air duct + termination.

  3. 03.

    Photo of the CO detector near the fireplace.

Guidance

Why open-hearth wood fireplaces are excluded

A traditional open-hearth wood fireplace operates at ~10% efficiency and releases PM2.5 indoor concentrations that frequently exceed EPA 24-hour limits within an hour of lighting. Modern sealed/vented inserts (EPA-certified to <2.0 g/hr) are dramatically cleaner and more efficient.

Note

Even sealed gas fireplaces should not be the primary heating source — they have lower combustion efficiency than a furnace, more potential for CO incidents, and contribute to depressurization issues. Treat them as decorative/supplemental.

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Indoor Air Quality & Health Required from Silver

Whole-House Fresh Air Supply

A whole-house mechanical fresh-air supply system is provided.

Scope

Continuous or intermittent mechanical ventilation that supplies outdoor air to the dwelling — separate from spot ventilation (bath fans, kitchen hood).

Requirements

  1. 01.

    Install a whole-house ventilation system meeting ASHRAE 62.2-2022 airflow minimums (typically 30-90 CFM for a 1500-3000 sf home, depending on bedrooms).

  2. 02.

    Acceptable system types: dedicated supply fan, exhaust-only with passive inlets, or balanced (supply + exhaust with optional heat recovery — required at Gold).

  3. 03.

    Run-time controls must ensure the design CFM is delivered as an average over each 4-hour period.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    ASHRAE 62.2 ventilation calculation worksheet showing required CFM for the dwelling.

  2. 02.

    Ventilation system spec sheet + photo of installed fan / controls.

  3. 03.

    Flow test confirming delivered CFM at the grille(s).

Guidance

Why tight houses need this

Modern construction is tight enough that natural infiltration alone no longer dilutes indoor pollutants to safe levels — VOCs from finishes, CO2 from occupants, moisture from cooking/showering, and (for the unlucky) radon all accumulate. The whole-house fan is the air-quality equivalent of a circulating pump in a plumbing system.

Resources

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Indoor Air Quality & Health Required from Silver

Sealed/Vented New Gas Appliances

Any new gas appliances are sealed-combustion / vented to the outdoors — or the project goes all-electric.

Scope

All NEW gas appliances installed in the dwelling — furnace, boiler, water heater, dryer, fireplace.

Requirements

  1. 01.

    New gas appliances must be sealed-combustion (direct-vent) — drawing combustion air from outside and exhausting to outside through dedicated venting.

  2. 02.

    Atmospherically vented or naturally drafted gas appliances are not permitted for new installations at Silver and above.

  3. 03.

    OR the project may convert to all-electric appliances (which automatically satisfies the requirement plus aligns with Gold all-electric goals).

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Equipment spec sheets for all new gas appliances showing sealed-combustion / direct-vent design.

  2. 02.

    Photos of installed combustion-air intake and exhaust terminations.

Guidance

Why sealed-combustion is now baseline

Atmospheric-draft appliances are dependent on neutral house pressure to vent properly — they backdraft in any home with strong exhaust fans (kitchen hood, bath fans, dryer) or wind effects. Sealed-combustion appliances are immune to backdrafting because the entire combustion air/exhaust path is isolated from house air.

Note

Most furnaces sold in the U.S. today are already sealed-combustion (95%+ AFUE condensing units). Atmospheric-draft is most commonly found in older tank water heaters — replacement with a sealed-combustion or electric HPWH is the easiest path.

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Indoor Air Quality & Health Required from Silver

Kitchen Ventilation

Kitchen has proper ventilation via range hood, outdoor air system, or air-quality monitor. (At Platinum, the range hood must detect PM2.5 and activate automatically.)

Scope

Kitchen ventilation supplementing or extending the basic range hood requirement.

Requirements

  1. 01.

    Install one of: (a) range hood ducted outdoors and flow-tested at ≥ 100 CFM at the hood face; (b) dedicated kitchen exhaust fan; or (c) an indoor air-quality monitor that triggers ventilation when PM2.5, CO, or VOCs spike.

  2. 02.

    At Platinum, the range hood must include automatic activation triggered by a PM2.5 sensor (typical threshold: 35 µg/m³).

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Hood spec + flow test record at the hood face (not the fan, not the duct).

  2. 02.

    For Platinum: PM2.5 sensor spec sheet and integration with the range hood control.

Guidance

100 CFM at the hood face — what that means

Many high-end "1000 CFM" range hoods deliver only 200-400 CFM at the hood face because of undersized ducting, multiple elbows, or a long run to the exterior. Flow-test at the hood face (with the hood running on its highest setting and the kitchen door closed) is the only meaningful verification.

Note

Larger ducts (6" round minimum, 8" preferred) and short, straight runs make a huge difference. Avoid more than two 90° elbows. Roof terminations are typically lower-resistance than wall terminations.

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Indoor Air Quality & Health Required from Gold

Balanced Fresh-Air System

A balanced (supply + exhaust) fresh-air system is installed and tested.

Scope

Mechanical ventilation system delivering balanced supply and exhaust airflow — HRV (heat recovery ventilator) or ERV (energy recovery ventilator).

Requirements

  1. 01.

    Install a dedicated HRV or ERV sized to ASHRAE 62.2-2022 ventilation rates for the dwelling.

  2. 02.

    Commission with a balance test: measured supply CFM and exhaust CFM must be within 10% of each other.

  3. 03.

    Supply ducting must distribute fresh air to bedrooms and main living areas; exhaust ducting must pull from kitchen, bathrooms, and laundry.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    HRV/ERV spec sheet showing sensible recovery efficiency (≥ 60% for cold climates, ≥ 70% for ENERGY STAR).

  2. 02.

    Commissioning test report showing measured supply CFM, exhaust CFM, and the balance percentage.

  3. 03.

    Marked floor plan showing supply and exhaust grille locations.

Guidance

HRV vs ERV — which to pick

HRV recovers sensible heat only (temperature). ERV recovers both sensible heat and latent (humidity). Use ERV in hot-humid climates (Zones 2-3) to keep summer humidity out, and in cold-dry climates (Zones 6-7) to keep winter humidity in. HRV is acceptable in mixed climates (Zones 4-5) where humidity transfer is less critical.

Resources

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Indoor Air Quality & Health Required from Gold

Indoor Air Quality Sensor

RESET-certified air-quality sensor installed in the main living area or ducts. (At Platinum, sensor measures CO₂, TVOC, humidity, temp, and PM2.5.)

Scope

Continuous indoor air-quality monitoring in the dwelling.

Requirements

  1. 01.

    Install a RESET-certified or ENERGY STAR-recognized air-quality sensor in the main living area, or in the return-air duct.

  2. 02.

    Sensor must measure PM2.5 at minimum. Additional sensors for CO2, TVOC, humidity, and temperature are encouraged.

  3. 03.

    At Platinum: sensor must measure CO2, TVOC, humidity, temperature, AND PM2.5 (full RESET Grade B).

  4. 04.

    Sensor data must be accessible to the occupant via a display or mobile app.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Sensor spec sheet with the measured pollutants listed.

  2. 02.

    Photo of installed sensor in the main living area.

  3. 03.

    Screenshot of the occupant's monitoring app showing live readings.

Guidance

Why monitoring is the missing piece

A home can have a great ventilation system, low-VOC finishes, and HEPA filtration — and still have unexpected IAQ events from cooking, candles, new furniture off-gassing, or wildfire smoke. Continuous monitoring lets the occupant notice and act on these events rather than living with them.

Resources

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Indoor Air Quality & Health Required from Platinum

Ventilation with Heat/Energy Recovery or Smart Controls

Ventilation includes energy-recovery / heat-recovery (ERV/HRV) or smart-control features.

Scope

The whole-house ventilation system, building on the Silver and Gold ventilation requirements.

Requirements

  1. 01.

    Ventilation must include heat recovery (HRV) or energy recovery (ERV) with a minimum 70% sensible recovery efficiency.

  2. 02.

    OR the system must include smart-control features (CO2 demand-controlled, occupancy-triggered, scheduled per-room boost).

  3. 03.

    Either pathway must include continuous monitoring of supply CFM and integration with the IAQ sensor required at Gold.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    HRV/ERV spec showing SRE ≥ 70%, OR smart-control system spec showing the demand-control logic.

  2. 02.

    Photo of installed unit and control interface.

  3. 03.

    Integration documentation showing the IAQ sensor → ventilation control link.

Guidance

Smart-control ventilation

Demand-controlled ventilation throttles based on actual indoor air quality — runs harder when CO2 is high (people present) or when PM2.5 spikes (cooking, wildfire). Result: same air quality as continuous-run ventilation with 30-50% less fan energy and less conditioned-air exhaust.

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Indoor Air Quality & Health Required from Platinum

Whole-Home Humidity Control

Whole-home dehumidification / humidification provided where appropriate by climate (target 40–50°F dewpoint).

Scope

Whole-home humidity management — dehumidification in cooling season, humidification in heating season, as appropriate to climate.

Requirements

  1. 01.

    Install a whole-home dehumidifier (typically integrated with the HVAC return) sized for the dwelling.

  2. 02.

    Target dewpoint range: 40-55°F (corresponds to ~30-50% RH at typical indoor temperatures).

  3. 03.

    In cold-dry climates (Zones 6-8), add a whole-home humidifier to prevent winter RH dropping below 30%.

  4. 04.

    Controls must be tied to the IAQ sensor required at Gold.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Dehumidifier (and humidifier where applicable) spec sheets showing pint/day capacity and integration.

  2. 02.

    Photo of installed unit + control interface.

  3. 03.

    Initial commissioning record showing RH/dewpoint readings in main living area.

Guidance

Why dehumidification is separate from AC

In hot-humid climates, a properly-sized AC removes humidity as a side effect of cooling — but only when it's running. During mild "shoulder" periods (May, October), the AC doesn't run enough to control humidity, and indoor RH can climb to 65-75%. A dedicated dehumidifier handles the gap.

Note

Mold growth becomes likely above 60% sustained RH on cool surfaces. Most building scientists recommend keeping RH between 30% (winter floor) and 50% (summer ceiling). Below 30% causes static, dry skin, increased respiratory infection; above 60% causes mold + dust mite growth.

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Indoor Air Quality & Health Required from Platinum

No Indoor Combustion Fireplace

No combustion fireplaces present indoors. Electric fireplaces permitted.

Scope

Any indoor combustion-based fireplace (wood, gas, pellet, ethanol).

Requirements

  1. 01.

    No combustion fireplace permitted indoors at Platinum tier.

  2. 02.

    Electric fireplaces (decorative or heating) are permitted and recommended as a substitute.

  3. 03.

    Outdoor combustion fireplaces / fire pits are not subject to this requirement.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Confirmation statement (signed by Owner/Project Team) that no combustion fireplace exists indoors.

  2. 02.

    If an existing combustion fireplace was decommissioned: photos showing the unit removed or permanently sealed.

Guidance

Why the Platinum ban

Even sealed/vented combustion fireplaces (a) create combustion-safety risk, (b) require makeup air that defeats some of the envelope tightening, and (c) emit PM2.5 outdoors that affects the neighborhood. Electric fireplaces eliminate all three concerns while providing equivalent ambience.

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Indoor Air Quality & Health

Healthier Home (Clean Living)

Project goes beyond baseline IAQ requirements with low-emission materials, advanced filtration, and active monitoring.

Description

The Healthier Home (Clean Living) badge recognizes projects that go meaningfully beyond the GreenStar baseline for indoor air quality and occupant health. The baseline already addresses combustion safety, radon, fresh-air ventilation, and filtration. The badge pushes further on three fronts: lower-emission materials at the surfaces occupants actually touch, advanced filtration on the air they breathe, and active monitoring so problems are caught early instead of discovered chronically.

Earning the badge does not require pursuing Platinum — but the Platinum-tier IAQ requirements (MERV 16 filter, advanced sensor for CO₂/TVOC/PM2.5/humidity/temperature, balanced ventilation with heat recovery) define the practical ceiling and provide the most common compliance path.

Required standard requirements

To earn this badge, the project must meet:

Additional badge criteria

Low-emission materials

  1. 01.

    Interior paints, coatings, sealants, and adhesives meet GreenSeal GS-11 / GS-36 / GS-47 emissions standards (or SCS Indoor Advantage Gold, FloorScore, or GreenGuard Gold equivalents).

  2. 02.

    All composite-wood panels (cabinetry, millwork, subfloor) meet CARB Phase 2 or TSCA Title VI for formaldehyde emissions.

  3. 03.

    New carpet, resilient flooring, and engineered wood floors carry FloorScore, Green Label Plus, or GreenGuard Gold certification.

  4. 04.

    No added flame retardants in installed furniture, mattresses, or upholstered seating where occupants control the spec (PBDEs, chlorinated tris explicitly excluded).

Advanced filtration

  1. 01.

    MERV 13 minimum on all ducted HVAC return paths (MERV 16 strongly preferred and required where the Platinum tier is being claimed alongside the badge).

  2. 02.

    Whole-house HEPA filtration on the fresh-air supply OR a dedicated bedroom-area HEPA air purifier rated for the served volume (CADR ≥ 2/3 of room area in sq ft).

  3. 03.

    Activated carbon stage on the kitchen range-hood filter or a downstream pre-filter — required where any combustion remains in the home.

Active monitoring

  1. 01.

    Continuous IAQ sensor installed in the primary living area, measuring at minimum: CO₂, total VOC, PM2.5, temperature, and relative humidity. RESET-certified sensors qualify automatically.

  2. 02.

    Sensor must be readable via on-device display or app, with alert thresholds configured for CO₂ > 1,000 ppm, PM2.5 > 35 µg/m³, and humidity outside 30–60% RH.

  3. 03.

    Sensor data exportable for at least 30 days of history (rolling) to support post-occupancy review.

Documentation

  1. 01.

    Material spec sheets / certificates for all paints, sealants, composite woods, and flooring.

  2. 02.

    Filter spec sheet showing MERV rating + photo of installed unit; HEPA unit cut sheet if used.

  3. 03.

    Sensor cut sheet + photo of installed location + screenshot of a recent reading showing the measured parameters.

  4. 04.

    Occupant orientation: homeowner/tenant briefed on filter-change cadence, sensor alerts, and ventilation operation.

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Indoor Air Quality & Health

Reduced Electromagnetic Frequency (EMF)

Wiring, lighting, and wireless infrastructure designed to minimize EMF exposure for occupants.

Description

The Reduced EMF badge recognizes homes whose wiring, lighting, and wireless infrastructure are designed to minimize occupant exposure to electromagnetic fields. The badge is intended for occupants with diagnosed electromagnetic hypersensitivity (EHS) or with a preference, supported by their physician, to limit ambient EMF — and for builders who want to offer that option as a design discipline.

The badge does not require a particular EMF threshold be met everywhere in the home. It requires that the home was designed with EMF reduction as an explicit constraint and that a post-construction survey verifies the design intent at the sleeping areas, where occupants spend the longest continuous exposure.

GreenStar is agnostic about the EMF-health debate; the badge serves owners who want this as a build option, similar to how the Foam-free badge serves owners with chemical sensitivities.

Required standard requirements

To earn this badge, the project must meet:

Additional badge criteria

Wiring & circuits

  1. 01.

    All branch-circuit wiring run as twisted or shielded cable (MC armor, metal conduit, or twisted-pair Romex equivalents). No untwisted parallel hot/neutral runs above the sleeping floor.

  2. 02.

    No knob-and-tube wiring (already required at Certified tier for existing homes) and no ungrounded two-wire circuits.

  3. 03.

    Dedicated "kill switches" — manual or smart-relay disconnects — at the electrical panel for the bedroom-area circuits, allowing occupants to de-energize sleeping areas during the night.

  4. 04.

    No bedroom outlets backed against the head-of-bed wall on the opposite side (i.e. neighbor's panel, kitchen panel, refrigerator); relocate or shield where unavoidable.

Lighting

  1. 01.

    No CFL lighting in sleeping areas (CFLs emit high "dirty electricity" — line-frequency harmonics).

  2. 02.

    LED drivers in sleeping areas selected for low flicker (modulation < 5% per IEEE 1789) and low EMI emission (FCC Part 15 Class B or better).

  3. 03.

    No magnetic-ballast fluorescent fixtures anywhere in the dwelling.

Wireless infrastructure

  1. 01.

    Ethernet drops (Cat 6 minimum) to all primary work, study, and media locations — Ethernet-first as the default network path.

  2. 02.

    Wi-Fi access points sited away from sleeping areas, with at least one wired-bedroom-network option offered.

  3. 03.

    Smart-home hubs and any in-wall radios sited outside bedrooms (utility room, garage, or central closet).

  4. 04.

    Mesh-network nodes counted as wireless transmitters and sited per the same separation rule.

Verification survey

  1. 01.

    Post-construction EMF survey by a building-biologist-certified or IBE-certified rater (or equivalent), measuring at minimum: AC magnetic field, AC electric field, RF/microwave power density, and dirty electricity.

  2. 02.

    Sleeping-area readings: AC magnetic field < 1 mG, AC electric field < 1 V/m, RF power density < 10 µW/m² (BBP "no concern" thresholds).

  3. 03.

    Living-area readings documented (no maximum threshold required for living spaces but readings reported on the certificate).

Documentation

  1. 01.

    EMF survey report from the certified rater with floor-plan-annotated readings.

  2. 02.

    Electrical plans showing the bedroom-circuit kill-switch panel layout.

  3. 03.

    Cable spec sheets (MC, shielded Romex, etc.) and LED driver specs for sleeping-area fixtures.

  4. 04.

    Photographs of the panel kill switches, Ethernet drops, and AP / hub locations.

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