Reference

The full standard

All 54 requirements grouped by pillar. Pick a certification level to see everything it takes, describe your project to hide what doesn't apply, or focus one pillar. Tap any card to slide in the full detail.

Level
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Pillar

Showing 54 of 54

Silver+ = becomes required at that level and every level above; unmarked requirements apply at every level Badge name = doing this also counts toward that optional badge

Pillar 1

Energy & Climate Resilience (12)

Pillar 2

Indoor Air Quality & Health (16)

  • Bathroom Exhaust Ventilation

    Counts toward Healthier Home (Clean Living)

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

    Open

  • Carbon Monoxide Detectors

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

    Open

  • Carbon Monoxide Testing of Combustion Appliances

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

    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

  • Gas Leak Inspection

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

    Open

  • HVAC Filter Rating

    Stepped · 4 tiers Counts toward Healthier Home (Clean Living)

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

    Open

  • Radon Testing and Mitigation

    Counts toward Healthier Home (Clean Living)

    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

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

    Counts toward Healthier Home (Clean Living)

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

    Open

  • Kitchen Ventilation

    Silver+ Counts toward Healthier Home (Clean Living)

    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

  • Sealed/Vented New Gas Appliances

    Silver+

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

    Open

  • Whole-House Fresh Air Supply

    Silver+ Counts toward Healthier Home (Clean Living)

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

    Open

  • Balanced Fresh-Air System

    Gold+ Counts toward Healthier Home (Clean Living)

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

    Open

  • Indoor Air Quality Sensor

    Gold+ Counts toward Healthier Home (Clean Living) Reduced Electromagnetic Frequency (EMF)

    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

  • No Indoor Combustion Fireplace

    Platinum+

    No combustion fireplaces present indoors. Electric fireplaces permitted.

    Open

  • Ventilation with Heat/Energy Recovery or Smart Controls

    Platinum+ Counts toward Healthier Home (Clean Living)

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

    Open

  • Whole-Home Humidity Control

    Platinum+ Counts toward Healthier Home (Clean Living)

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

    Open

Pillar 3

Water Efficiency & Management (11)

  • Bathroom Aerator Flow Rate

    Stepped · 4 tiers Counts toward Zero Water Capable Home Water Score

    Average measured flow rate of all bathroom faucet aerators.

    Open

  • Clothes Washer Leak Protection

    Counts toward Home Water Score

    Use steel-braided supply hoses, OR install a drain pan under the clothes washer.

    Open

  • Plumbing Leak & Pressure Test

    Counts toward Zero Water Capable Home Water Score

    Pressure test the plumbing system; no leaks permitted. Documented via the LEED-format Water Pressure and Leak Verification Report.

    Open

  • Showerhead Flow Rate

    Stepped · 4 tiers Counts toward Zero Water Capable Home Water Score

    Average measured flow rate of all showerheads in the home. Alternative pathway: meet a Home Water Score threshold.

    Open

  • Tank Water Heater Drain Pan

    Install a drain pan under any tank water heater located in or above conditioned living space.

    Open

  • Toilet Flush Volume

    Stepped · 4 tiers Counts toward Zero Water Capable Home Water Score

    Average flush volume across all toilets in the home.

    Open

  • Cold-Water Pipe Insulation

    Gold+ Counts toward Zero Water Capable

    Insulate cold-water pipes, or keep them out of unconditioned space.

    Open

  • On-Demand Well-Water Softener

    Gold+

    Where well water is the supply, use an on-demand softener.

    Open

  • Tap Water Filtration

    Gold+ Counts toward Zero Water Capable

    Install tap-water filtration appropriate to local water-quality conditions.

    Open

  • Advanced Hot Water Delivery Test

    Platinum+ Counts toward Home Water Score

    Hot-water delivery passes the advanced test: ≤ 0.6 gallons before delivery and +10°F temperature rise.

    Open

  • Water Leak Detection & Real-Time Metering

    Platinum+ Counts toward Zero Water Capable Resilience Home Water Score

    Real-time water leak detection and metering system installed.

    Open

Pillar 4

Moisture & Structural Integrity (7)

  • Functional Gutter System

    Counts toward Nature-friendly Storm Water Control

    Gutters drain water well away from the foundation — OR site has well-draining sandy soils verified per USDA classification.

    Open

  • Moisture & Wall Water Leak Assessment

    Counts toward Nature-friendly Storm Water Control

    Inspect roof condition, flashing, gutters, siding, ground slope, basement moisture (meter), and visible mold/mildew. Repair findings.

    Open

  • Certified Shower/Tub Surrounds

    Silver+

    New shower/tub surrounds use ASTM D3273-certified wallboard, certified coating, or drywall-free construction.

    Open

  • Moisture-Resistant Flooring in Wet Areas

    Silver+

    Bathrooms, kitchens, main entryways, and laundry rooms use moisture-resistant flooring.

    Open

  • No New Ducts Panned in Joists

    Silver+ New construction only

    No newly installed ducts are panned in floor joists — they must be fully ducted to prevent unintended air paths.

    Open

  • Site Grading or French Drains

    Silver+ New construction only Counts toward Nature-friendly Storm Water Control

    Grading slopes away from the home — or french drains are installed (new construction).

    Open

  • All Ducts Fully Ducted

    Platinum+

    All HVAC ducts are fully ducted — none panned in joists.

    Open

Pillar 5

Materials & Environmental Impact (8)

  • Asbestos Mitigation

    Existing buildings only Counts toward Sustainable Materials

    Mitigate any asbestos found, or document that none is present.

    Open

  • Embodied Carbon Reduction

    New construction only Stepped · 4 tiers Counts toward GHI Zero Carbon Certified Foam-free Sustainable Materials

    Reduction in upfront embodied carbon below the 154 kg CO₂e/m² baseline. Approved tools: Beam Estimator, EC3, PHPP (PH Ribbon). Alternative pathways available at Silver (no concrete, RECs, solar offset, small home).

    Open

  • Knob-and-Tube Wiring Removed

    Existing buildings only Counts toward Reduced Electromagnetic Frequency (EMF)

    No knob-and-tube wiring remains active in the home.

    Open

  • Lead Paint Assessment (Pre-1978 Homes)

    Existing buildings only Counts toward Sustainable Materials

    Review and resolve any potential lead-paint issues. Document via the Lead Abatement acknowledgement template.

    Open

  • Building Maintenance Instructions

    Silver+ Counts toward Accessibility Resilience

    Create written instructions documenting how to maintain the building, equipment, and finishes.

    Open

  • Homeowner / Tenant Training

    Silver+ Counts toward Accessibility Resilience

    Train the homeowner or tenant on how to operate and maintain the building.

    Open

  • Certified Wood (No Tropical Species)

    Gold+ New construction only Counts toward Sustainable Materials

    New wood products are FSC or SFI certified. No tropical wood.

    Open

  • Floorscore or Green Label Plus Carpet

    Platinum+ New construction only Counts toward Sustainable Materials

    Any new carpet is Floorscore or Green Label Plus certified.

    Open
Energy & Climate Resilience Required at every level Resilience Nature-friendly Walkability

Climate Risk Assessment

Determine the project's future climate risks using a climate-resource tool. Document and mitigate identified risks (stringency rises by tier).

Scope

Site-specific climate risks over the project's expected lifetime (typically 30-60 years), identified using a recognized climate-projection tool.

Requirements

Assessment + mitigation

  1. 01.

    Run the project address through a climate-risk tool such as NOAA's Climate Explorer, FEMA's National Risk Index, or the U.S. Climate Resilience Toolkit.

  2. 02.

    Identify the top risks for the project location — typical categories: extreme heat days, wildfire, riverine/coastal flooding, hurricane/severe wind, drought, freeze events.

  3. 03.

    Document a mitigation strategy for each identified risk. The stringency rises by tier: Certified must mitigate the highest risk; Silver and above must mitigate progressively more.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Climate-risk report exported from NOAA Climate Explorer, FEMA NRI, or equivalent tool, dated within 12 months of registration.

  2. 02.

    Mitigation plan listing each risk and the specific design or operational response (e.g. "high heat → install 200A panel for future heat-pump upgrade; specify R-21 walls").

Guidance

Why this is the first requirement

Climate risk drives many of the downstream Energy and Moisture decisions in this standard — sizing cooling for the higher peak days, hardening the envelope against wildfire, raising the foundation in flood-prone areas. Doing the assessment up front makes the rest of the certification easier to defend.

Tools

Example — A typical risk → mitigation chain

Project in central Texas: top risks come back as extreme heat (highest), drought (high), and severe wind/hail (high). Mitigation: oversized HVAC return + R-21 walls + cool roof for heat; xeriscape + rainwater catchment for drought; impact-rated windows + reinforced roof anchors for wind. Each mitigation aligns with a separate GreenStar requirement, so the climate report becomes the design narrative.

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Energy & Climate Resilience Required at every level GHI Zero Energy Certified GHI Zero Energy Ready Certified Reduced Electromagnetic Frequency (EMF)

Majority LED Lighting

A majority of fixtures use LED lamps.

Scope

All interior and exterior lighting fixtures in the dwelling. Decorative-only fixtures (e.g. chandeliers used <1 hr/day) count toward the total.

Requirements

  1. 01.

    At least 50% of installed lamp sockets must be fitted with LED lamps or LED-integrated fixtures (Certified threshold).

  2. 02.

    For Gold+, the practical target is >90% LED — incandescent + halogen should be limited to specialty applications (oven, refrigerator, niche decorative).

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Lighting inventory listing each fixture type, lamp type (LED / CFL / halogen / incandescent), and count. Spreadsheet or marked-up floor plan both acceptable.

  2. 02.

    OR purchase receipts / fixture spec sheets showing LED-integrated rating for new construction.

Guidance

Quality over count

A "majority LED" count check can pass with low-CRI cheap bulbs that look terrible. For long-term satisfaction, specify ≥90 CRI bulbs and a consistent color temperature (2700K-3000K for residential spaces). ENERGY STAR-rated LEDs include color rendering and lifetime requirements.

Note

Dimmer compatibility is a common failure point — many older incandescent dimmers cause LED flicker. Replace dimmers when swapping to LED, or specify "dimmable LED" + a matched LED-compatible dimmer (Lutron Diva, Leviton SureSlide, etc.).

Resources

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Energy & Climate Resilience Required at every level

Air Leakage Between Attached Units

Reduce air movement between attached housing units. Stringency tightens at higher tiers (ACH50 thresholds differ for new construction vs. renovation).

Spec by tier

TierSpec
CertifiedReduce air leaks between attached units (no specific threshold)
Silver0.3 ACH50 (new) / 0.4 (existing) between units
Gold0.23 ACH50 (new) / 0.3 (renovation) between units
Platinum0.15 ACH50 (new) / 0.23 (renovation) between units

Scope

Air leakage between adjoining dwelling units in attached housing — duplex, townhouse, multifamily, ADU sharing a wall. Single-family detached homes are exempt.

Requirements

Performance targets

  1. 01.

    Perform a blower-door test specifically isolating air leakage between the test unit and adjoining units (pressurize the test unit and measure airflow into the neighbor units).

  2. 02.

    Measured air leakage between units must meet the tier threshold in the "Spec by tier" table above. Each tier has separate values for new construction and existing/renovation.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Blower-door test report from a RESNET-certified or BPI-certified rater, showing inter-unit air leakage measurements in CFM50 or ACH50.

  2. 02.

    Floor plan marked with leak-test locations.

Guidance

Why it matters more in attached housing

In a single-family detached home, air leakage means heat loss + comfort issues — annoying, not unsafe. In attached housing, inter-unit air leakage moves combustion gases, cooking odors, allergens, secondhand smoke, and noise between dwelling units. A unit can fail its CO test because of a neighbor's furnace.

Common leak locations

Shared chases for plumbing and HVAC, electrical penetrations through the demising wall, unsealed top plates above the demising wall (especially under a common attic), and gaps where the demising wall meets exterior walls. Aerosolized sealant ("AeroBarrier") is increasingly used in multifamily new construction for hard-to-reach demising-wall seams.

Resources

  • ASTM E779 — Air Leakage Measurement

    The blower-door test method most jurisdictions reference.

  • AeroBarrier →

    Aerosolized envelope sealant used to hit aggressive ACH50 targets without manual caulking.

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Energy & Climate Resilience Required at Silver and above GHI Zero Energy Certified GHI Zero Carbon Certified GHI Zero Energy Ready Certified Foam-free

Home Energy Performance

DOE Home Energy Score (existing) or modeled annual energy use (new construction). Alternative tools include HERS, PHPP, WUFI Passive, BeOpt, and 90.1.

Spec by tier

TierSpec
CertifiedNot required at this tier
SilverDOE Home Energy Score of 6
GoldDOE Home Energy Score of 8
PlatinumDOE Home Energy Score of 10 (existing) — or 17.5 MBtu/year (new construction)

Scope

Whole-house energy performance, rated using DOE Home Energy Score or an equivalent recognized rating tool.

Requirements

Performance targets

  1. 01.

    Engage a qualified DOE Home Energy Score assessor (or equivalent: HERS rater, PHIUS verifier) to score the home.

  2. 02.

    Score must meet or exceed the tier threshold in the "Spec by tier" table above. For new construction, the equivalent thresholds in modeled annual energy use (MBtu/year) apply.

  3. 03.

    Acceptable alternative scoring tools: HERS Index, PHIUS+, Passive House Planning Package (PHPP), BeOpt, ASHRAE 90.1 modeled output.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    DOE Home Energy Score report from a certified assessor — includes the score (1-10), label-style summary, and improvement recommendations.

  2. 02.

    OR equivalent: HERS Index report, PHIUS verification, PHPP output, or BeOpt modeling output.

Guidance

How the Home Energy Score scale works

DOE Home Energy Score is a 1-10 scale based on modeled annual energy use per square foot, normalized for local climate. A score of 5 represents the U.S. average existing home; a score of 10 represents the best 10% of homes nationally. The score is asset-based (not consumption-based), so it reflects the building itself rather than how the occupants use it.

Why one tier might map to several scores

A Gold-tier home (score 8) modeled at the local 99% design temperature lands in roughly the same actual annual consumption as a 17.5 MBtu/year new build — the standard accepts either pathway. Use whichever tool your rater is certified for; results are interchangeable for compliance.

Resources

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Energy & Climate Resilience Required at Silver and above

Properly Sized Cooling Equipment

Cooling equipment sized per ACCA Manual J 8th Edition (or equivalent load calculation).

Scope

All air-conditioning and heat-pump equipment installed for space cooling — central, mini-split, and packaged systems.

Requirements

  1. 01.

    Cooling equipment sized using ACCA Manual J 8th Edition load calculation, or an equivalent ASHRAE-recognized method.

  2. 02.

    Installed nominal capacity must not exceed the Manual J calculated load by more than 15% (oversizing causes humidity issues and short-cycling).

  3. 03.

    Manual S equipment selection and Manual D duct design (where applicable) must accompany the load calc.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Manual J load-calculation report prepared by an ACCA-certified or equivalent professional, listing room-by-room sensible + latent loads.

  2. 02.

    Equipment cut sheet for installed AC/HP showing the AHRI-rated capacity at design conditions.

  3. 03.

    Manual S equipment selection rationale (if separate from the Manual J).

Guidance

Why oversizing is harmful

Most U.S. homes have AC oversized by 50-100% — a leftover habit from the days of poorly-insulated houses and pre-Manual-J rules of thumb. Oversized AC short-cycles (cools the air without removing humidity), leaving the home cool but clammy. It also wastes 5-25% more energy than a properly-sized unit.

Note

Heat pumps follow the same sizing rule but additionally need to be checked against the heating load at the local 99% design temperature — undersizing causes auxiliary resistance heat to kick in too often. Use ACCA Manual J + Manual S for both heating and cooling capacity selection.

Resources

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Energy & Climate Resilience Required at Silver and above

Refrigerant Charge Verification

Refrigerant charge test completed on all AC and heat-pump equipment.

Scope

All split-system AC and heat-pump equipment installed (factory-charged window/PTAC units excluded).

Requirements

  1. 01.

    Verify refrigerant charge using the subcooling method (TXV systems) or superheat method (fixed-orifice systems), per ACCA Quality Installation Standard.

  2. 02.

    Charge must fall within the manufacturer's specified target range for the system at the test conditions.

  3. 03.

    If charge is off, adjust before sign-off and re-verify.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Signed refrigerant charge test record per installed unit, listing model number, outdoor temperature at test, measured superheat or subcooling, and manufacturer target range.

Guidance

Why charge matters so much

A typical residential AC system underperforms by 5-20% when charge is off by even 10%. Industry surveys consistently find 60%+ of new installations have improper charge — this requirement catches that during commissioning rather than after months of high bills.

Resources

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Energy & Climate Resilience Required at Gold and above GHI Zero Energy Certified GHI Zero Carbon Certified GHI Zero Energy Ready Certified Electrified Living Peak Load Shaver

All-Electric or Dual-Fuel Heating

Space heating is all-electric or dual-fuel/hybrid. (At Platinum, all-electric only.)

Scope

The primary space-heating system — central heat pump, ducted air handler, mini-split, or hydronic system.

Requirements

  1. 01.

    At Gold: space heating must be either (a) all-electric (heat pump preferred, resistance backup OK) or (b) a dual-fuel hybrid system (heat pump primary, gas backup for extreme cold).

  2. 02.

    At Platinum: all-electric only. Dual-fuel is not accepted.

  3. 03.

    Heat-pump capacity must be sized to meet 100% of the heating load at the local 99% winter design temperature (per Manual J), or a supplementary heat source must cover the gap.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Equipment spec sheet for installed heat pump showing HSPF2 (≥ 8.1 for ENERGY STAR cold-climate, ≥ 8.5 for cold-climate ENERGY STAR Most Efficient).

  2. 02.

    Manual J load calculation showing the heating load at design temperature and the equipment capacity at that temperature.

  3. 03.

    For dual-fuel systems: thermostat configuration documentation showing the changeover temperature (typically 20-35°F).

Guidance

Cold-climate heat pump selection

Modern variable-speed heat pumps maintain 100% of nameplate capacity down to 5°F and 75%+ down to -15°F — well past where dual-fuel systems used to be necessary. NEEP's Cold-Climate Heat Pump list filters for systems that maintain capacity at low temperatures. ENERGY STAR Cold Climate label is the easiest filter.

Resources

Note

IRA federal tax credit covers 30% of installed cost up to $2,000 for qualifying HPs. Many states stack additional rebates of $1,000-$8,000 through utility programs.

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Energy & Climate Resilience Required at Gold and above GHI Zero Energy Certified GHI Zero Carbon Certified GHI Zero Energy Ready Certified Electrified Living Peak Load Shaver

All-Electric or Solar Water Heating

Water heating is all-electric (heat pump preferred) or solar.

Scope

The primary domestic hot-water heater serving the dwelling. Recirculation loops and point-of-use boosters are downstream of this and not constrained by this requirement.

Requirements

  1. 01.

    The primary water heater must be either: (a) a heat-pump water heater (HPWH), (b) an electric-resistance water heater, or (c) a solar-thermal system with an electric backup.

  2. 02.

    HPWH is strongly preferred — it delivers the same hot water with ~70% less electricity than resistance.

  3. 03.

    For Platinum, electric-resistance alone is not sufficient (HPWH or solar required).

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Manufacturer spec sheet showing UEF (Uniform Energy Factor) ≥ 2.0 for HPWH or ≥ 0.92 for resistance.

  2. 02.

    Photo of the installed unit with model number visible.

  3. 03.

    For HPWH: documentation that the installation location meets the minimum ambient air-volume requirement (typically 1000 cu ft, or ducted intake/exhaust).

Guidance

Heat-pump water heaters in practice

HPWHs need ambient heat to extract — they actually cool the room they're in by ~5°F and dehumidify it. Ideal locations: garage in warm climates, basement, dedicated utility room. Avoid bedrooms (compressor noise is real) and very small closets without ducting. Hybrid units allow electric-resistance fallback for high-demand periods.

Resources

Note

Federal Inflation Reduction Act offers a 30% tax credit (up to $2,000) for HPWHs through 2032, plus utility rebates of $500-$1,500 in many areas. Stack these for under $1,000 net installed cost on many models.

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Energy & Climate Resilience Required at Gold and above GHI Zero Energy Certified GHI Zero Carbon Certified GHI Zero Energy Ready Certified Electrified Living

All-Electric Cooking

Cooking appliances are all-electric.

Scope

All primary cooking appliances in the dwelling — cooktop, range, oven, wall oven, microwave-convection. Outdoor grills and supplementary appliances (toaster oven, slow cooker) are excluded.

Requirements

  1. 01.

    All installed cooking appliances must be electric — either induction or electric resistance.

  2. 02.

    Induction is strongly preferred for performance and indoor air quality.

  3. 03.

    If existing gas hookups remain, they must be capped per local code.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Equipment spec sheets for cooktop, oven, and any other installed cooking appliance.

  2. 02.

    Photo of installed appliances.

  3. 03.

    Plumber sign-off on gas-line capping (if applicable).

Guidance

Induction vs electric resistance

Induction heats the pan directly via electromagnetic field — boils water roughly 50% faster than gas, with finer temperature control than either gas or resistance. Downsides: only works with magnetic cookware (cast iron, magnetic stainless), and quality units are more expensive. Electric resistance ("smoothtop") is cheaper, works with any cookware, but slower and less responsive.

Note

Switching from gas to induction often requires upgrading from a 120V outlet to a 240V circuit — confirm electrical panel capacity early in design. Portable induction burners (110V, 1800W) are a useful try-before-you-buy option.

Resources

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Energy & Climate Resilience Required at Gold and above GHI Zero Energy Certified GHI Zero Carbon Certified GHI Zero Energy Ready Certified Electrified Living Peak Load Shaver

All-Electric Dryer

Clothes dryer is all-electric (heat-pump dryer preferred).

Scope

The primary clothes dryer in the dwelling.

Requirements

  1. 01.

    The clothes dryer must be electric. Heat-pump dryers are strongly preferred over electric-resistance vented dryers.

  2. 02.

    If a gas dryer is being replaced, the gas line must be capped per local code.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Equipment spec sheet for installed dryer showing combined energy factor (CEF) — typical HP dryers are 5-7+, resistance vented dryers are 3-4.

  2. 02.

    Photo of installed unit.

Guidance

Heat-pump dryers in practice

HP dryers use ~50% less electricity than vented resistance dryers, are ventless (so no exterior wall penetration needed), and operate at lower temperatures (gentler on fabrics). Tradeoffs: cycle time is ~25% longer, and the condensate needs to drain (either to a drain line or a removable tank).

Note

Ventless HP dryers can be installed in apartments and tight spaces with no exterior wall — opens up laundry placement options. Most newer models (Whirlpool, LG, Miele, GE) qualify for the ENERGY STAR Most Efficient list.

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Energy & Climate Resilience Required at Platinum and above Resilience Peak Load Shaver

Time-of-Use / Peak-Load Appliances

Major appliances support time-of-use scheduling and/or peak-load avoidance.

Scope

Major-load appliances: HVAC, water heater, EV charger, electric dryer, dishwasher, and (where present) battery storage system.

Requirements

  1. 01.

    At least the major-load appliances above (where installed) must support time-of-use scheduling, demand response, or peak-load avoidance — via smart-appliance controls, smart-home hub, or utility demand-response program.

  2. 02.

    Where the local utility offers TOU rates, the project must be enrolled in a TOU rate plan.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Inventory of installed smart appliances with model numbers, listing the demand-response or scheduling capability of each (e.g. CTA-2045 compliant water heater, ENERGY STAR Connected dryer, ChargePoint EV charger with TOU scheduling).

  2. 02.

    Confirmation of utility TOU rate enrollment (utility statement or screenshot).

  3. 03.

    Photo or screenshot showing scheduling configured in the smart-home hub.

Guidance

Why this matters at Platinum

A home that consumes the same kWh as the grid average but shifts those kWh off-peak avoids 30-60% of the carbon intensity of grid power (peak hours = dirtiest marginal generation in most U.S. markets). It also unlocks 10-40% savings on the utility bill under TOU rates. Without smart appliances, this is impractical to achieve manually.

Resources

  • CTA-2045 — Modular Communication Interface for Energy Management

    The open standard for utility-controllable appliances. Most newer HPWHs and EV chargers support it.

  • ENERGY STAR Connected Products →

    Searchable list of appliances with verified smart-connectivity features.

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Energy & Climate Resilience Required at Platinum and above GHI Zero Energy Certified GHI Zero Carbon Certified GHI Zero Energy Ready Certified Resilience Walkability Peak Load Shaver

Solar- and EV-Ready Electrical Service

200-amp breaker box with capacity to add future solar PV and electric-vehicle chargers.

Scope

The main electrical service panel and the conduit/wiring runs from panel to roof and panel to the EV-charging location.

Requirements

  1. 01.

    Main service must be at least 200 amps.

  2. 02.

    Panel must have a dedicated 60A+ breaker space reserved for future solar PV interconnection (NEC 705 backfeed).

  3. 03.

    Panel must have a dedicated 40A+ breaker space (with conduit run + outlet box) for a Level 2 EV charger.

  4. 04.

    Conduit must be run from the main panel to the roof (for future solar inverter) and from the panel to the primary parking space (for the EV charger).

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Panel schedule listing all breakers, with the reserved solar + EV breakers labeled.

  2. 02.

    Photo of the installed panel.

  3. 03.

    Marked-up electrical plan showing the conduit runs and termination points.

  4. 04.

    Electrical permit + final inspection sign-off.

Guidance

Why this is cheap to do now and expensive later

Adding the EV-ready conduit + 240V outlet during initial wiring costs ~$300-$800. Retrofitting after drywall and finishes are in often costs $2,000-$5,000 and may require surface-mounted conduit. The panel + solar conduit story is similar.

Resources

  • NEC 705 — Interconnected Power Production Sources

    Code section governing solar backfeed. The most common compliance path is the 120% rule: PV breaker + main breaker ≤ 120% of panel busbar rating.

  • EV Charger Installation Cost Guide →

    DOE guide to Level 2 charging selection and installation.

Note

SB-100 (California), HB 6-1-23 (Colorado), and similar state laws now require new construction to be EV-ready. Even where not required by code, the resale premium for EV-ready homes is documented at $1,500-$3,500.

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Indoor Air Quality & Health Required at every level Healthier Home (Clean Living)

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 at every level Healthier Home (Clean Living)

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 at every level Healthier Home (Clean Living)

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 at every level

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 at every level

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 at every level

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 at every level Healthier Home (Clean Living)

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 at every level

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 at Silver and above Healthier Home (Clean Living)

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 at Silver and above

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 at Silver and above Healthier Home (Clean Living)

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 at Gold and above Healthier Home (Clean Living)

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 at Gold and above Healthier Home (Clean Living) Reduced Electromagnetic Frequency (EMF)

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 at Platinum and above Healthier Home (Clean Living)

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 at Platinum and above Healthier Home (Clean Living)

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 at Platinum and above

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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Water Efficiency & Management Required at every level Zero Water Capable Home Water Score

Showerhead Flow Rate

Average measured flow rate of all showerheads in the home. Alternative pathway: meet a Home Water Score threshold.

Spec by tier

TierSpec
Certified≤ 2.2 GPM average — or Home Water Score of 2
Silver≤ 2.0 GPM average — or Home Water Score of 3
Gold≤ 1.5 GPM average — or Home Water Score of 5
Platinum≤ 1.25 GPM average — or Home Water Score of 6

Scope

All showerheads installed in the dwelling unit, including primary, guest, and accessory bathrooms. Hand-held wands count as part of the fixture they share a valve with. Bathtub spouts and tub-only fillers are excluded.

Requirements

Performance targets

  1. 01.

    Measure the flow rate (GPM) of every showerhead in the home, then calculate the average across all heads.

  2. 02.

    The average GPM must meet the tier threshold shown in the "Spec by tier" table above. Hand-held wands are measured separately and included in the average.

  3. 03.

    Alternative pathway: the project may submit a Home Water Score report meeting the tier threshold in lieu of per-fixture measurement.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Photo of each showerhead's manufacturer rating sticker or packaging showing rated GPM (and WaterSense label if applicable).

  2. 02.

    OR a field flow-test record for each showerhead, including date, room location, measured flow rate, and inspector signature.

  3. 03.

    OR a completed Home Water Score report referencing the dwelling and showing the required score.

Guidance

Why flow rate matters

Showerheads are typically the second-largest indoor water draw after toilets, and they pull from the water heater — so cutting shower flow saves both water and the energy used to heat it. EPA WaterSense estimates a typical household saves ~2,700 gallons of water and 330 kWh of electricity per year by switching from a 2.5 GPM head to a 1.5 GPM WaterSense head.

Field flow-test procedure

When the manufacturer rating is missing or you want field verification:

  1. 01.

    Set up

    Hold a graduated 1-gallon flow bag (or a calibrated container) under the showerhead. Turn the shower on full hot and full cold so the mixing valve runs at the same total flow it would in normal use.

  2. 02.

    Capture

    Once steady-state flow is reached (3-5 seconds), start a timer and capture water for exactly 10 seconds.

  3. 03.

    Calculate

    Divide the captured volume (gallons) by 10, then multiply by 60 to get GPM. Example: 0.25 gal in 10 sec × 6 = 1.5 GPM.

  4. 04.

    Record

    Record the result on the flow-test form along with the room/fixture identifier.

Resources

Note

WaterSense ratings are measured at 80 psi static pressure. Actual field flow at lower house pressures (most homes run 40-60 psi) may be lower than the sticker value, which is fine — the spec accepts the manufacturer rating as the documented value.

Example — Averaging across fixtures

A 4-bathroom home has showerheads rated at 1.5, 1.5, 1.8, and 1.5 GPM. The average is 1.575 GPM — passes Silver (≤ 2.0) and Gold (≤ 1.5? No, 1.575 > 1.5). To clear Gold, the 1.8 GPM head would need to be swapped for one ≤ 1.0 GPM, or all four upgraded to 1.5 GPM caps.

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Water Efficiency & Management Required at every level Zero Water Capable Home Water Score

Bathroom Aerator Flow Rate

Average measured flow rate of all bathroom faucet aerators.

Spec by tier

TierSpec
Certified≤ 2.0 GPM average — or Home Water Score of 2
Silver≤ 1.75 GPM average — or Home Water Score of 3
Gold≤ 1.0 GPM average — or Home Water Score of 5
Platinum≤ 0.5 GPM average — or Home Water Score of 6

Scope

Aerators on every bathroom lavatory (sink) faucet in the dwelling. Kitchen, utility, and laundry-sink aerators are excluded.

Requirements

Performance targets

  1. 01.

    Measure or read the rated flow rate (GPM) of every bathroom faucet aerator in the home.

  2. 02.

    Calculate the average GPM across all bathroom aerators; the average must meet the tier threshold in the "Spec by tier" table.

  3. 03.

    Alternative pathway: submit a Home Water Score report meeting the tier threshold in lieu of per-fixture measurement.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Photo of each bathroom aerator showing the stamped GPM rating (typically printed on the underside or on the packaging).

  2. 02.

    OR field flow-test record (date, location, measured GPM, signature) for each aerator.

  3. 03.

    OR a Home Water Score report referencing the dwelling.

Guidance

How to read an aerator

Bathroom aerators are stamped with their flow rate in tiny letters on the underside, on the side ring, or on the original packaging. The most common ratings are 0.5, 1.0, 1.5, 2.0, and 2.2 GPM. WaterSense-labeled aerators max out at 1.5 GPM and produce noticeably softer spray.

Swapping a non-compliant aerator

Most aerators swap in under a minute with no tools:

  1. 01.

    Unscrew

    Unscrew the existing aerator by hand (counterclockwise as you look up at it). If it is stuck, wrap with a rag and use slip-joint pliers gently.

  2. 02.

    Match thread

    Bathroom aerators come in male (M22 or M24) and female (M22x1) thread. Bring the old one to the store to match.

  3. 03.

    Install

    Hand-tighten the replacement with the included washer. No tools or thread tape required.

  4. 04.

    Test

    Run full flow for 10 seconds and re-measure to confirm.

Resources

Note

For Platinum, the 0.5 GPM target is aggressive but workable in bathrooms (faucets are used mostly for short hand-washing bursts). Kitchen faucets generally cannot run that low and are not covered by this requirement.

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Water Efficiency & Management Required at every level Zero Water Capable Home Water Score

Toilet Flush Volume

Average flush volume across all toilets in the home.

Spec by tier

TierSpec
Certified< 1.6 GPF average — or Home Water Score of 2
Silver< 1.3 GPF average — or Home Water Score of 3
Gold≤ 1.0 GPF average — or Home Water Score of 5
Platinum< 1.0 GPF average — or Home Water Score of 6

Scope

Every toilet installed in the dwelling unit, including dual-flush models. Bathtubs, urinals (residential only), and bidets are excluded.

Requirements

Performance targets

  1. 01.

    Identify the rated GPF (gallons per flush) for every toilet in the home. For dual-flush toilets, use the higher of the two flush volumes (full flush) for compliance calculations.

  2. 02.

    Calculate the average rated GPF; the average must meet the tier threshold in the "Spec by tier" table.

  3. 03.

    Alternative pathway: submit a Home Water Score report meeting the tier threshold.

  4. 04.

    New construction at Silver and above must install only toilets meeting the tier threshold — averaging in older fixtures is not permitted on new builds.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Photo of each toilet's manufacturer rating (cast or printed on the bowl behind the seat or on the underside of the tank lid) showing GPF.

  2. 02.

    OR completed measurement record (bucket-and-stopwatch method) for each toilet.

  3. 03.

    OR Home Water Score report.

Guidance

How dual-flush counts

For a 1.6/1.1 GPF dual-flush toilet, GreenStar counts the 1.6 GPF full flush — not a weighted average. The rationale is that occupants do not always select the appropriate flush, so the standard assumes worst-case usage. Single-flush 1.28 GPF WaterSense toilets typically outperform dual-flush models on this basis.

Retrofit options

For existing toilets above the threshold: (a) replace the toilet with a WaterSense unit, (b) install an adjustable dual-flush conversion kit (some are accepted by GHI; verify with the inspector before relying on this), or (c) install a tank fill-cycle diverter / displacement bag to reduce flush volume — last-resort, only useful for marginal cases.

Resources

Example — Averaging a mixed home

A 3-toilet home has units rated 1.6, 1.28, and 1.28 GPF. The average is 1.387 GPF — passes Certified (<1.6) but fails Silver (<1.3). Swapping the 1.6 GPF unit for a 1.28 brings the average to 1.28 — passes Silver and Gold (≤1.0? No, 1.28 > 1.0).

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Water Efficiency & Management Required at every level Zero Water Capable Home Water Score

Plumbing Leak & Pressure Test

Pressure test the plumbing system; no leaks permitted. Documented via the LEED-format Water Pressure and Leak Verification Report.

Scope

All cold- and hot-water supply piping inside the dwelling envelope, from the point of entry (meter or well pressure tank) through every fixture connection.

Requirements

  1. 01.

    Pressurize the supply system per local plumbing code (typically 60-100 psi static or 1.5× working pressure, whichever is higher).

  2. 02.

    Hold the test pressure for the code-required duration (commonly 15 minutes for the basic test) with all fixtures closed.

  3. 03.

    Pressure must hold with zero observable drop. Any pressure loss requires the leak to be located and repaired before retesting.

  4. 04.

    On new construction, the test must be performed before drywall is closed in over the supply lines.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Completed LEED-format Water Pressure and Leak Verification Report (or equivalent) signed by the plumber or GreenHome Inspector.

  2. 02.

    Photo or scan of the pressure-test gauge at start and end of the hold period (if available).

Guidance

Why it matters

A single 1/16-inch supply-line leak behind drywall can waste 15+ gallons per day and cause thousands of dollars in moisture damage before being noticed. The pressure test is the single most cost-effective failure check in residential plumbing.

Field procedure

Most plumbers run this as part of rough-in. For existing-home retrofits:

  1. 01.

    Isolate

    Shut off all fixtures and close the main shutoff temporarily; open one fixture briefly to confirm system pressure has not fluctuated.

  2. 02.

    Gauge

    Attach a pressure gauge at the outdoor hose bib or a service tee. Note the static pressure.

  3. 03.

    Hold

    Re-pressurize and observe the gauge for the required hold period. A drop of even 1-2 psi indicates a leak.

  4. 04.

    Locate

    If pressure drops, isolate sections (hot vs. cold, upper vs. lower floors) by closing intermediate valves and re-running to narrow down the location.

Note

Pressure tests do not catch slow leaks at fittings under normal operating pressure that only show up under thermal cycling. Bath fan and water-leak inspections during the moisture assessment cover those.

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Water Efficiency & Management Required at every level Home Water Score

Clothes Washer Leak Protection

Use steel-braided supply hoses, OR install a drain pan under the clothes washer.

Scope

Every clothes washer installation in the dwelling, including stacked or laundry-closet units.

Requirements

  1. 01.

    Install stainless-steel-braided supply hoses (both hot and cold) — OR install a drain pan with a plumbed drain under the washer.

  2. 02.

    Either solution is acceptable. Some inspectors prefer the pan even with braided hoses for second-floor laundry rooms.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Photo of the installed supply hoses showing the braided stainless sheath at both hot and cold connections.

  2. 02.

    OR photo of the installed drain pan with the plumbed drain line and where it discharges (floor drain, standpipe, or exterior).

Guidance

Why this is so cheap and high-impact

Standard rubber washing-machine supply hoses are the #1 cause of indoor water damage claims to insurers in North America. A burst rubber hose can dump 5-10 gallons per minute behind the washer until the water main is shut off. Braided stainless hoses cost ~$15/pair and last 10-15 years. Drain pans cost ~$30 and provide a backup if the hose still fails.

Note

Connect a smart water sensor (e.g. Flo by Moen, Phyn, even a $20 standalone unit) inside the drain pan or behind the washer for early-warning alerts. Not required, but it pairs naturally with this requirement.

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Water Efficiency & Management Required at every level

Tank Water Heater Drain Pan

Install a drain pan under any tank water heater located in or above conditioned living space.

Scope

Tank-style water heaters located in or above conditioned living space (e.g. utility closets on upper floors, attic installations). Garage and basement installations are excluded if a tank failure would not damage living space.

Requirements

  1. 01.

    Install a drain pan rated to fully contain a worst-case tank-failure leak under the water heater.

  2. 02.

    The pan must have a plumbed drain line routed to a safe discharge point (floor drain, exterior wall, or condensate line) per IPC §504.7.

  3. 03.

    Pan material: galvanized steel (≥ 24 ga) or aluminum, OR plastic rated for sustained 140°F exposure.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Photo of the installed pan showing the tank seated in it and the drain line connection.

  2. 02.

    Photo of where the drain line discharges (must be visible / observable per code).

Guidance

Tankless heaters

Tankless water heaters are exempt from this requirement — their failure mode is leak-free (they shut off on internal fault). However, GHI recommends still installing a small drip pan + sensor under tankless units mounted in conditioned space, since fittings on cold-water inlet and TPR valves can still fail.

Pan sizing

The pan must extend at least 2 inches beyond the tank diameter on all sides per most jurisdictions. Standard pans come in 22", 24", 26", and 28" diameters — match to your tank.

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Water Efficiency & Management Required at Gold and above Zero Water Capable

Cold-Water Pipe Insulation

Insulate cold-water pipes, or keep them out of unconditioned space.

Scope

Cold-water supply lines running through any unconditioned space (attics, crawlspaces, exterior walls in cold climates, garages, vented soffits).

Requirements

  1. 01.

    Insulate all cold-water supply lines passing through unconditioned space with closed-cell foam pipe sleeves of R-3 minimum (commonly 3/8" or 1/2" wall thickness).

  2. 02.

    OR route all cold-water supply lines through conditioned space only, eliminating exposure to unconditioned conditions.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Photos of insulated cold-water runs showing foam sleeve coverage at joints, tees, and elbows.

  2. 02.

    OR marked-up architectural drawings showing all cold-water lines routed through conditioned space (acceptable for new construction).

Guidance

Why insulate cold lines (not just hot)

Two reasons: (1) prevents condensation / "sweating" on cold pipes during humid weather, which can drip into wall cavities and cause hidden moisture damage; (2) reduces freeze risk in cold climates where pipes pass through unconditioned space. The energy savings are minor compared to hot-water insulation, but the moisture-management benefit is significant.

Note

Pair cold-water insulation with R-3+ hot-water insulation on the same runs. Hot-water insulation is a baseline expectation and reduces standby losses by 4-9% per the DOE.

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Water Efficiency & Management Required at Gold and above Zero Water Capable

Tap Water Filtration

Install tap-water filtration appropriate to local water-quality conditions.

Scope

The primary drinking-water tap (typically the kitchen sink cold tap). Whole-house filtration is acceptable but not required.

Requirements

  1. 01.

    Obtain or request the local Consumer Confidence Report (CCR) from the water utility, or — for well water — perform a current water-quality test.

  2. 02.

    Install a point-of-use or whole-house filtration system rated to remove the specific contaminants flagged in the CCR or well test.

  3. 03.

    At minimum, the filter must hold an NSF/ANSI 42 certification (aesthetic — chlorine, taste, odor) for treated municipal water. NSF/ANSI 53 (health-related: lead, cysts, VOCs) or 401 (emerging contaminants) is required where those contaminants are present.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Copy of the CCR or well water-quality test results highlighting contaminants of concern.

  2. 02.

    Filter specification sheet showing matching NSF/ANSI certifications.

  3. 03.

    Photo of installed filter with model number visible.

Guidance

Reading a CCR

Every U.S. public water utility publishes an annual Consumer Confidence Report listing detected contaminants and their levels relative to the MCL (maximum contaminant level). Items at or near MCL — especially lead, chromium-6, nitrates, disinfection byproducts (TTHMs), PFAS — should drive the filter selection.

Filter types

Pitcher / faucet-mount filters meet the spirit of the requirement only if certified for the specific contaminants. Under-sink activated-carbon block units (e.g. Multipure, AquaTru, Berkey countertop) are typically the highest-performing point-of-use option. Whole-house systems are appropriate only for chlorine and sediment — they do not effectively remove dissolved metals or PFAS.

Resources

Note

Filter cartridges have a finite life — typically 6-12 months for carbon, 5-10 years for reverse osmosis membranes. Document the replacement cadence in the building maintenance instructions.

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Water Efficiency & Management Required at Gold and above

On-Demand Well-Water Softener

Where well water is the supply, use an on-demand softener.

Scope

Dwellings on well water with measured hardness above 7 grains per gallon (gpg) or 120 mg/L as CaCO₃.

Requirements

  1. 01.

    Install a demand-initiated regeneration (DIR) water softener — also called metered or on-demand. Time-clock-only softeners are not permitted.

  2. 02.

    Softener must be sized to the household water-use volume and source hardness.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Well-water hardness test result (current within 12 months).

  2. 02.

    Softener manufacturer spec sheet showing demand-initiated regeneration control.

  3. 03.

    Photo of installed unit with model number and capacity rating visible.

Guidance

Why demand-initiated, not time-clock

Time-clock softeners regenerate on a fixed schedule (e.g. every 3 days) regardless of actual water use. A typical 4-person household with a time-clock softener wastes 5,000-15,000 gallons of water and 200-500 lbs of salt per year compared to a demand-initiated unit, which regenerates only after the resin bed has actually been depleted.

Twin-tank vs single-tank

Twin-tank softeners (e.g. Kinetico) provide continuous soft water during regeneration and use roughly 30% less salt + water than single-tank units. Higher upfront cost but the lowest lifetime operating cost.

Note

Potassium chloride salt is a sodium-free alternative for households with dietary sodium restrictions. Costs ~3× more than NaCl pellets but works in any DIR softener.

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Water Efficiency & Management Required at Platinum and above Home Water Score

Advanced Hot Water Delivery Test

Hot-water delivery passes the advanced test: ≤ 0.6 gallons before delivery and +10°F temperature rise.

Scope

Hot-water distribution from the water heater (or recirculation manifold) to the farthest hot-water fixture in the home.

Requirements

Performance targets

  1. 01.

    At the farthest fixture from the water heater, less than 0.6 gallons must be drawn before hot water arrives (measured from cold start, fixture wide open).

  2. 02.

    Within the same draw, the temperature must rise at least 10°F above the incoming cold-water temperature.

  3. 03.

    Test at every "long-run" fixture (any fixture more than 20 ft of pipe from the water heater).

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Completed hot-water delivery test record listing each tested fixture with: distance from heater, gallons drawn before delivery, peak temperature reached, time elapsed.

  2. 02.

    Architectural plumbing layout showing hot-water distribution (trunk-and-branch, home-run manifold, or recirculation loop).

Guidance

Why this matters

In a typical home, 10-25% of all hot water drawn never reaches the fixture — it cools in the pipe between uses. A home that passes the 0.6 gal / +10°F test saves 5,000-15,000 gallons of water per year and the energy used to heat it, plus shortens the wait time at the tap (under 10 seconds typical for compliant homes).

Design strategies

Compliance comes from one or more of: (a) home-run manifold distribution with 3/8" PEX trunks, (b) trunk-and-branch with the heater centrally located, (c) on-demand or temperature-modulated recirculation pump at the farthest fixture, (d) point-of-use water heaters for distant fixtures. Insulating hot lines to R-3 helps marginally.

Resources

  • PMI Hot Water Delivery System Performance — research

    Industry research showing typical hot-water wait times across distribution types.

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Water Efficiency & Management Required at Platinum and above Zero Water Capable Resilience Home Water Score

Water Leak Detection & Real-Time Metering

Real-time water leak detection and metering system installed.

Scope

Whole-home plumbing — the system must monitor the entire supply line for unusual flow patterns indicative of a leak.

Requirements

  1. 01.

    Install a whole-home water monitoring + leak detection system at the main supply line (post-meter, pre-distribution).

  2. 02.

    System must provide real-time flow data accessible via mobile app or web interface.

  3. 03.

    System must detect anomalous flow (continuous flow exceeding a threshold, indicating a likely leak) and alert the occupant within 1 hour.

  4. 04.

    Automatic water shutoff capability is strongly recommended but not required (alert-only systems are acceptable).

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    System specification sheet (Flo by Moen, Phyn Plus, Sense Save, etc.) showing real-time metering + alert capability.

  2. 02.

    Photo of the installed unit at the main supply line.

  3. 03.

    Screenshot of the occupant's mobile app showing live data from the unit.

Guidance

Auto-shutoff vs alert-only

Auto-shutoff systems (Flo, Phyn Plus) close the main water valve when a leak is detected — they prevent damage even if the occupant ignores the alert. Alert-only systems (Sense Save, Streamlabs) are cheaper but rely on the occupant acting promptly. For Platinum-level homes, auto-shutoff is the better fit even though the requirement is permissive.

Pair with point sensors

Whole-home meters detect supply-line leaks but miss drain-side issues (washer drain backup, toilet overflow). Add inexpensive Wi-Fi water sensors under sinks, behind toilets, near the water heater, and in the laundry pan. Most whole-home systems pair with these as a unified alerting system.

Note

Many insurance carriers (Travelers, Liberty Mutual, Nationwide) offer 3-15% homeowner premium discounts for installed leak detection. Have the homeowner submit the device certification to their carrier after installation.

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Moisture & Structural Integrity Required at every level Nature-friendly Storm Water Control

Moisture & Wall Water Leak Assessment

Inspect roof condition, flashing, gutters, siding, ground slope, basement moisture (meter), and visible mold/mildew. Repair findings.

Scope

The entire dwelling envelope and grounds — roof, flashing, gutters, siding, foundation, basement/crawlspace, around plumbing penetrations, and visible interior surfaces.

Requirements

Inspection checklist

  1. 01.

    Inspect roof condition: missing/damaged shingles, exposed nails, sealant failures around penetrations (vents, chimneys, skylights).

  2. 02.

    Inspect flashing: chimney, skylight, dormer, kickout/step flashing at roof-wall intersections.

  3. 03.

    Inspect siding: cracks, sealant failures around windows and doors, weep holes clear (for brick veneer).

  4. 04.

    Inspect ground slope around the foundation: must drop at least 6 inches over the first 10 feet (6% slope) away from the building.

  5. 05.

    Use a moisture meter on basement walls, crawlspace, and any area showing past water staining.

  6. 06.

    Visually inspect for active mold, mildew, or water staining throughout the dwelling.

  7. 07.

    Document any findings; address all active leaks or moisture issues before certification.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Inspector's moisture/leak assessment report with photos of each inspection point.

  2. 02.

    Moisture meter readings (basement, crawlspace, any wet area).

  3. 03.

    Repair documentation for any findings — receipts, photos, contractor sign-off.

Guidance

Why this is the most consequential single check

Water intrusion is the #1 cause of premature building failure. A small unaddressed roof or flashing leak can rot framing, feed mold, ruin insulation, and corrode metal connectors within 1-3 years. The full envelope inspection at certification catches these before they become structural.

Common findings + what they cost to fix

Failed kickout flashing at the roof-wall junction (~$200-$500 to repair, prevents thousands in wall rot). Clogged gutters or downspouts dumping water at the foundation ($100-$300 to clear/extend). Negative grade (soil sloping toward house) — $500-$2,000 to regrade.

Note

A moisture meter ($30-$100) gives quantitative readings. Pin meters insert into the material; pinless meters use electrical capacitance. For walls and trim, pinless is non-destructive and good for screening; pin meters give the most accurate reading at depth.

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Moisture & Structural Integrity Required at every level Nature-friendly Storm Water Control

Functional Gutter System

Gutters drain water well away from the foundation — OR site has well-draining sandy soils verified per USDA classification.

Scope

Roof drainage system — gutters, downspouts, splash blocks, and the ground area where roof water terminates.

Requirements

Choose one path

  1. 01.

    Standard path: install gutters that fully capture roof runoff, with downspouts that discharge a minimum of 4 feet from the foundation (extended via splash blocks, underground drains, or extensions).

  2. 02.

    Soil exemption: site has well-draining sandy soils (USDA classification: sand, loamy sand, sandy loam) verified by a soil test or USDA Web Soil Survey lookup. In this case gutters are optional.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Photos of installed gutters + downspouts + termination points.

  2. 02.

    OR (soil exemption): USDA Web Soil Survey report for the project parcel showing eligible sandy soil classification.

Guidance

Why downspout extensions matter so much

A 1-inch rainfall on a 2000 sf roof produces 1,200 gallons of water. If that volume drops within 1 foot of the foundation, it saturates the soil there, raises hydrostatic pressure on the foundation wall, and over years pushes water into the basement. 4-foot downspout extensions are the single cheapest fix for basement leaks — $5-$30 per downspout.

Resources

Note

In tight urban sites where 4-foot extensions aren't feasible, underground PVC drain to a daylight termination or dry well is acceptable. Sump pump discharge does not count — that's water already inside the building.

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Moisture & Structural Integrity Required at Silver and above Nature-friendly Storm Water Control

Site Grading or French Drains

Grading slopes away from the home — or french drains are installed (new construction).

Scope

Site grading and subsurface drainage in new construction projects.

Requirements

Choose one path

  1. 01.

    Grading path: site must be graded to slope away from the foundation at a minimum of 6 inches over the first 10 feet (6% slope), continuing to drop at least 2% beyond that.

  2. 02.

    French drain path: where grading is constrained (urban sites, retaining walls, sloped lots), install a perimeter French drain at the foundation footing depth, connected to a daylight termination, dry well, or storm sewer.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Civil/grading plan stamped by the project engineer showing the slope profile.

  2. 02.

    OR French drain detail drawing + photos of installation before backfill.

Guidance

Why the 6/10 rule

IRC R401.3 specifies the 6"/10ft (6%) minimum positive grade away from foundations. Below that slope, surface water sheets toward the foundation during heavy rain and saturates the perimeter soil. Above 6%, the slope is steep enough that water consistently drains away even on saturated ground.

Note

On urban infill lots where positive grading is impossible (e.g. neighbor's lot drops toward yours), French drains combined with a sump pump (interior or exterior) become the only practical solution. Plan for the sump pump in the electrical load at the climate-risk assessment stage.

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Moisture & Structural Integrity Required at Silver and above

No New Ducts Panned in Joists

No newly installed ducts are panned in floor joists — they must be fully ducted to prevent unintended air paths.

Scope

Newly installed HVAC return-air ductwork in new construction.

Requirements

  1. 01.

    No new HVAC return-air ducts may be "panned" — using the cavity between floor joists, capped with sheet metal, as the duct.

  2. 02.

    All return-air ductwork must be fully ducted (rigid metal or insulated flex), sealed at every joint with UL-181 rated mastic or tape.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Photos of installed return-air ducts showing rigid or flex construction with sealed joints.

  2. 02.

    Marked-up mechanical plan confirming no panned joist bays.

Guidance

Why panned joists fail

A panned joist bay relies on the floor framing as the duct surface — which means every gap in the framing (around nails, knockouts, end joints, plumbing penetrations) becomes a leak. Field studies consistently find 20-40% air leakage in panned-joist returns, which directly degrades HVAC efficiency and creates pressure imbalances that drive pollutants into the house from the basement/crawlspace.

Note

Existing panned-joist returns in renovation projects are not required to be removed — this Silver requirement applies to new ductwork only. At Platinum, all ducts (new + existing) must be fully ducted.

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Moisture & Structural Integrity Required at Silver and above

Moisture-Resistant Flooring in Wet Areas

Bathrooms, kitchens, main entryways, and laundry rooms use moisture-resistant flooring.

Scope

Floor finishes in wet areas: bathrooms, kitchens, main entryways, and laundry rooms.

Requirements

  1. 01.

    Install moisture-resistant flooring in all wet-area rooms: tile, sheet vinyl, LVT/LVP, sealed concrete, or marine-grade plywood with appropriate finish.

  2. 02.

    Carpet, unsealed wood, and laminate flooring are not permitted in wet-area rooms.

  3. 03.

    Transitions between wet-area and dry-area flooring must include a watertight seal (caulk or threshold).

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Photos of installed flooring in each wet-area room.

  2. 02.

    Material spec sheets confirming moisture-resistant rating.

Guidance

Engineered wood + LVP — the modern wet-area workhorses

Luxury vinyl plank (LVP) and waterproof engineered wood are both visually indistinguishable from real hardwood at typical viewing distance and fully waterproof. They've become the default for kitchens and bathrooms in green-built homes. Look for products with a wear layer of 20+ mil and a real waterproof core (SPC or WPC).

Note

Tile remains the gold standard for showers and high-splash areas. For radiant heating systems, tile + a decoupling membrane (Schluter Ditra, etc.) prevents cracking from substrate movement.

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Moisture & Structural Integrity Required at Silver and above

Certified Shower/Tub Surrounds

New shower/tub surrounds use ASTM D3273-certified wallboard, certified coating, or drywall-free construction.

Scope

Wall surfaces inside shower and bathtub surrounds — the wet zones behind tile, panels, or solid surface.

Requirements

Choose one substrate path

  1. 01.

    Tile path: substrate must be ASTM D3273-certified mold-resistant cement board (e.g. Hardiebacker, Durock) or equivalent, or a waterproof membrane system over standard substrate.

  2. 02.

    Coating path: apply a certified waterproofing membrane (Schluter Kerdi, RedGard, Hydroban) over the entire wet-zone substrate before finish.

  3. 03.

    Drywall-free path: install a one-piece fiberglass, acrylic, or solid-surface shower/tub surround unit (eliminates wet-zone seams entirely).

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Substrate or coating product spec sheet with ASTM D3273 (mold resistance) or ANSI A118.10 (waterproofing) certification.

  2. 02.

    Photo of substrate installation BEFORE tile/finish (so the inspector can verify the substrate type).

  3. 03.

    OR photo of one-piece surround installation.

Guidance

Why standard drywall fails in showers

Even moisture-resistant ("green board") drywall is not waterproof — moisture eventually wicks through grout lines, saturates the gypsum core, and creates mold inside the wall cavity. Cement board (water-tolerant but not waterproof) plus a waterproofing membrane is the modern standard. One-piece surrounds eliminate the seam-failure risk entirely.

Resources

  • TCNA Handbook for Ceramic, Glass, and Stone Tile Installation

    Industry reference for shower wet-zone construction. Methods W245 (membrane) and B415 (tile over backer board with topical waterproofing) are the most common compliance paths.

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Moisture & Structural Integrity Required at Platinum and above

All Ducts Fully Ducted

All HVAC ducts are fully ducted — none panned in joists.

Scope

All HVAC supply and return ductwork in the dwelling — new and existing.

Requirements

  1. 01.

    Every duct in the HVAC system must be fully ducted (rigid metal or insulated flex). No panned joist returns, building-cavity returns, or wall-stud-bay supplies.

  2. 02.

    All duct joints sealed with UL-181 rated mastic or tape.

  3. 03.

    Duct leakage test must show ≤ 4 CFM25 per 100 sf of conditioned floor area (or stricter local code).

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Duct leakage test report from a certified tester showing total system leakage in CFM25.

  2. 02.

    Photos of representative duct runs showing all-rigid or all-flex construction.

  3. 03.

    For renovation: marked-up plan showing replaced/rebuilt ducts where panned cavities were removed.

Guidance

Why this is Platinum-only

Retrofitting fully-ducted returns in an existing house with panned-joist returns is invasive — typically requires removing some ceiling drywall to install new round flex. New construction is straightforward. Platinum tier reflects the level of envelope discipline required to actually achieve this end-state.

Resources

  • ASHRAE 152 — Method of Test for Determining the Design and Seasonal Efficiencies of Residential Thermal Distribution Systems

    The protocol behind duct leakage testing.

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Materials & Environmental Impact Required at every level Sustainable Materials

Lead Paint Assessment (Pre-1978 Homes)

Review and resolve any potential lead-paint issues. Document via the Lead Abatement acknowledgement template.

Scope

Lead paint and lead in plumbing fittings in dwellings built before 1978 (the year the U.S. banned residential lead-based paint).

Requirements

  1. 01.

    For pre-1978 dwellings: assess for lead-based paint on interior and exterior surfaces, including doors, windows, trim, and porches.

  2. 02.

    XRF analyzer testing OR EPA lead-paint test kit acceptable for screening; positive results require a certified lead inspector to confirm.

  3. 03.

    Any disturbance of lead-painted surfaces during the renovation must be performed by EPA RRP-certified contractors using lead-safe work practices.

  4. 04.

    Document final clearance: post-work dust-wipe sampling showing lead levels below the EPA clearance threshold (10 µg/sq ft for floors, 100 µg/sq ft for window sills).

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Lead paint test results (XRF, test kit, or lead inspector report).

  2. 02.

    EPA Lead Abatement acknowledgement template (signed by Owner/Project Team confirming awareness).

  3. 03.

    For lead-safe renovation work: RRP-certified contractor credentials + final clearance dust-wipe results.

Guidance

Why pre-1978 matters

The U.S. banned lead in residential paint in 1978. About 24 million U.S. homes built before that year still contain lead-based paint, primarily on window trim and doors where friction creates lead dust. Childhood lead exposure causes permanent neurological harm even at low levels — current CDC reference value is 3.5 µg/dL of blood, but no safe lead exposure level has been identified.

Resources

Note

Lead in plumbing solder was banned in 1986, and lead in pipes (1986 Safe Drinking Water Act). Pre-1986 plumbing with lead solder or lead service lines is a separate concern — covered under the Gold tap-water filtration requirement.

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Materials & Environmental Impact Required at every level Sustainable Materials

Asbestos Mitigation

Mitigate any asbestos found, or document that none is present.

Scope

Asbestos-containing materials in existing dwellings, typically built before the U.S. asbestos phase-out (1989-current, depending on product).

Requirements

  1. 01.

    For pre-1990 dwellings (and any later construction with suspect materials): a certified asbestos inspector must assess for ACM (asbestos-containing materials) in vinyl floor tiles, popcorn ceilings, pipe insulation, HVAC tape, roofing, and exterior siding.

  2. 02.

    Any ACM that is friable (crumbling) or being disturbed by the project must be abated by a licensed asbestos abatement contractor.

  3. 03.

    Stable, non-friable ACM that is not being disturbed may be left in place (encapsulated) — the certification standard is no exposure, not necessarily no asbestos.

  4. 04.

    Project team must document the abatement and provide air-clearance test results post-abatement.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Certified asbestos inspector report identifying all sampled materials, with lab test results (PLM or TEM analysis).

  2. 02.

    For abatement: contractor license + waste manifest showing proper disposal at a licensed facility.

  3. 03.

    Post-abatement air-clearance test results (< 0.01 fibers/cc).

Guidance

Why "no exposure" is the actual goal

Asbestos becomes a health risk when its fibers become airborne. Asbestos floor tiles in good condition under a layer of laminate are not a hazard. The same tiles being scraped up by a contractor without proper containment can release millions of fibers and cause mesothelioma exposure decades later. The standard requires that any ACM disturbance be done by licensed professionals.

Note

Suspect materials commonly missed: HVAC duct tape (especially silver cloth-backed tape from the 1960s-80s), Linoleum backing in 9x9 vinyl tile installations, transite siding (asbestos cement board) on mid-century homes, popcorn ceilings sprayed before 1980.

Resources

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Materials & Environmental Impact Required at every level Reduced Electromagnetic Frequency (EMF)

Knob-and-Tube Wiring Removed

No knob-and-tube wiring remains active in the home.

Scope

Knob-and-tube electrical wiring in existing dwellings (common in U.S. homes built 1880-1940).

Requirements

  1. 01.

    A licensed electrician must inspect the home for active knob-and-tube (K&T) wiring.

  2. 02.

    Any active K&T wiring must be replaced with modern grounded wiring before certification.

  3. 03.

    Inactive (disconnected) K&T may remain in place if confirmed by the electrician to be permanently disconnected from the panel.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Electrician's inspection report confirming presence/absence of active K&T.

  2. 02.

    For replacement work: electrical permit + final inspection sign-off.

Guidance

Why K&T is dangerous in a modern home

K&T wiring was rated for the loads of 1900-1940 (lights, irons, the occasional radio). It has no ground conductor, deteriorates over decades, and was never designed to operate in contact with insulation. Modern homes overload K&T circuits and trap heat in insulation around the wires — leading fire risk in pre-1940 housing stock.

Note

Insurance carriers increasingly refuse coverage or charge punitive premiums on homes with active K&T. Replacement during a renovation typically runs $5,000-$15,000 depending on access. It pays for itself in insurance savings and home value within a few years.

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Materials & Environmental Impact Required at every level GHI Zero Carbon Certified Foam-free Sustainable Materials

Embodied Carbon Reduction

Reduction in upfront embodied carbon below the 154 kg CO₂e/m² baseline. Approved tools: Beam Estimator, EC3, PHPP (PH Ribbon). Alternative pathways available at Silver (no concrete, RECs, solar offset, small home).

Spec by tier

TierSpec
CertifiedEmbodied-carbon evaluation required
Silver10% reduction from baseline
Gold15% reduction from baseline
Platinum30% reduction from baseline

Scope

Upfront embodied carbon (A1-A5 life-cycle stages) of new construction or major addition. Existing structure being kept in place is exempt by definition (zero new embodied carbon).

Requirements

Performance targets

  1. 01.

    At Certified: complete an embodied-carbon evaluation using an approved tool (Beam Estimator, EC3, PHPP / PH Ribbon). The evaluation must report total upfront kg CO₂e/m² for the project.

  2. 02.

    At Silver: reduce embodied carbon by at least 10% below the GreenStar baseline of 154 kg CO₂e/m².

  3. 03.

    At Gold: reduce by at least 15% below baseline.

  4. 04.

    At Platinum: reduce by at least 30% below baseline.

  5. 05.

    Alternative pathways accepted at Silver: build without concrete, OR purchase renewable energy credits equal to project embodied carbon, OR install solar PV offsetting embodied carbon over 30 years.

  6. 06.

    Small-home exemption: single-family ≤ 800 sf and multifamily units averaging ≤ 600 sf are exempt from the Silver+ percentage-reduction requirements (still complete the evaluation at Certified).

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Embodied-carbon report from an approved tool (Beam, EC3, PHPP) showing the project's upfront kg CO₂e/m² and the comparison to baseline.

  2. 02.

    Bill of materials including quantities (cubic yards of concrete, board feet of lumber, etc.) used in the calculation.

  3. 03.

    For alternative pathways at Silver: REC purchase certificate, solar system sizing calculation, or no-concrete design documentation.

Guidance

Why embodied carbon matters now

For a new high-efficiency home, embodied carbon (the carbon emitted to make the building materials) typically exceeds the operational carbon (heating/cooling/electric) for the first 30 years of the building's life. As the grid decarbonizes and homes become more efficient, embodied carbon becomes a larger share of total lifecycle impact. Choosing low-carbon concrete, wood-frame vs steel-frame, and reused materials makes a measurable difference.

The biggest reduction levers

Concrete is typically 30-50% of a home's embodied carbon. Switching from standard Portland cement concrete to a low-carbon mix (Type IL cement, fly ash or slag replacement at 30-50%, or specifying max OPC content) can cut concrete EC by 30-60% with no structural impact. Wood framing has dramatically lower EC than steel; insulation choice (mineral wool vs XPS foam) varies by 10x.

Resources

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Materials & Environmental Impact Required at Silver and above Accessibility Resilience

Building Maintenance Instructions

Create written instructions documenting how to maintain the building, equipment, and finishes.

Scope

Written documentation of how to maintain the building, equipment, and finishes — handed off to the homeowner or tenant at project completion.

Requirements

  1. 01.

    Create a building maintenance manual covering: HVAC filter changes, water heater service intervals, gutter cleaning schedule, exterior caulk inspection, smoke/CO detector battery replacement, recommended deep-cleaning cadence for finishes.

  2. 02.

    Include manufacturer warranties, model numbers, and contact information for major appliances and systems.

  3. 03.

    Document the GreenStar certification level and which requirements were met (so future owners understand the home's features).

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Completed maintenance manual (PDF or printed binder) delivered to the homeowner/tenant.

  2. 02.

    Homeowner/tenant signature confirming receipt.

Guidance

Why this is a Silver requirement, not Certified

The most well-designed green home will quietly degrade if the owner doesn't know which filter to buy or that the HRV needs filter changes too. The maintenance manual is the bridge between certification day and 10 years later — the difference between a home that holds its performance and one that drifts toward average.

Note

Many builders use a generic builder warranty book and bury the maintenance information. A standalone "GreenStar Owner's Manual" with the home-specific equipment list and a 1-page seasonal maintenance calendar is more likely to actually be used.

Resources

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Materials & Environmental Impact Required at Silver and above Accessibility Resilience

Homeowner / Tenant Training

Train the homeowner or tenant on how to operate and maintain the building.

Scope

In-person walkthrough and training session with the homeowner or tenant at project handover.

Requirements

  1. 01.

    GreenHome Inspector or builder must conduct an in-person training session with the homeowner/tenant covering: thermostat programming, HVAC filter location and changing, water shutoffs, electrical panel orientation, smoke/CO detector locations and testing.

  2. 02.

    Walk through the maintenance manual together and answer questions.

  3. 03.

    Demonstrate any complex systems (HPWH controls, smart appliances, HRV/ERV).

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Training agenda + sign-in sheet with homeowner/tenant signature.

  2. 02.

    Optional: photo or video of the training session for the project record.

Guidance

Why this matters more than people think

A heat-pump water heater set to "electric resistance only" defeats its energy savings. A thermostat with a wide deadband (8°F+) wastes energy and creates discomfort. An HRV with a clogged filter circulates dust instead of removing it. Many efficiency features fail at the user-interface level — and a 30-minute training session prevents most of those failures.

Note

Recording the training (with the homeowner's permission) and providing them with the video is increasingly common — homeowners watch it again 6 months later when they've forgotten something.

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Materials & Environmental Impact Required at Gold and above Sustainable Materials

Certified Wood (No Tropical Species)

New wood products are FSC or SFI certified. No tropical wood.

Scope

All new wood products installed in the dwelling — framing, flooring, trim, cabinetry, decking, structural panels.

Requirements

  1. 01.

    All newly installed wood products must carry FSC (Forest Stewardship Council) or SFI (Sustainable Forestry Initiative) certification.

  2. 02.

    No tropical hardwoods permitted (e.g. teak, mahogany, ipe, rosewood) — even when "certified," tropical sourcing carries unresolvable risks of forest conversion and illegal logging.

  3. 03.

    Salvaged or reclaimed wood is acceptable as an alternative pathway (counts toward the certified-wood requirement).

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Material spec sheets or invoices showing FSC/SFI certification logos and chain-of-custody numbers.

  2. 02.

    For reclaimed wood: supplier documentation of source.

Guidance

FSC vs SFI

FSC has stricter forest-management criteria, more independent governance, and broader endorsement from environmental groups. SFI is industry-developed and accepts a wider range of forestry practices. Both are accepted under GreenStar — preference for FSC where products are available, given the stronger third-party validation.

Why no tropical wood, even certified

Tropical forest deforestation continues to outpace certification efforts, and certified tropical wood often originates from forests adjacent to or recently converted from natural forest. Domestic temperate alternatives (oak, walnut, hickory, sapele) cover almost every use case at comparable price.

Resources

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Materials & Environmental Impact Required at Platinum and above Sustainable Materials

Floorscore or Green Label Plus Carpet

Any new carpet is Floorscore or Green Label Plus certified.

Scope

Any newly installed carpet in the dwelling. Existing carpet that is being kept in place is exempt.

Requirements

  1. 01.

    All new carpet must be FloorScore-certified OR Green Label Plus-certified for indoor air quality.

  2. 02.

    Carpet pad must also be certified (FloorScore or Green Label).

  3. 03.

    Adhesives (where used) must be low-VOC, meeting SCAQMD Rule 1168 or equivalent.

Documentation

Evidence the inspector / Institute will need.

  1. 01.

    Carpet spec sheets showing FloorScore or Green Label Plus certification.

  2. 02.

    Pad spec sheet with certification.

  3. 03.

    Adhesive spec sheet showing VOC content < 50 g/L.

Guidance

Why carpet is the IAQ requirement at Platinum

Carpet is the largest single VOC-emitting surface in many homes — formaldehyde from backing, styrene-butadiene from latex, and 4-PCH (the "new carpet smell"). Certified carpet emits these at low enough levels to meet CDPH 01350 standards for sensitive populations. Pad and adhesive are equally important — uncertified pad under certified carpet defeats the purpose.

Note

For lowest IAQ impact, consider hard-surface flooring with area rugs (which can be replaced and washed) instead of wall-to-wall carpet. The Platinum requirement applies only when new carpet IS installed.

Resources

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