GreenStar Homes Certification logo
Pillar
Tier
Project
Materials & Environmental Impact

Sustainable Materials

Materials are reclaimed, biobased, third-party certified, or otherwise selected for low environmental impact.

Sustainable Materials (placeholder seal) SM PLACEHOLDER

Description

The Sustainable Materials badge recognizes projects where a meaningful share of the material spend goes to products that are reclaimed, biobased, third-party certified, or otherwise selected for low environmental impact. Where the Embodied Carbon Reduction requirement focuses on the kg-CO₂e number, this badge focuses on the upstream story: where the material came from, who certified it, and whether it can be put back into the cycle at end of life.

The badge uses a points-based pathway so that projects can mix and match strategies — a project that uses heavily reclaimed materials, another that goes biobased, and a third that buys certified-sustainable conventional materials can all qualify.

Required standard requirements

To earn this badge, the project must meet all of the following existing GreenStar requirements:

Additional badge criteria

Beyond the required standard requirements above, the project must also satisfy:

Points pathway — achieve at least 8 points across the categories below

  1. 01.

    [2 pts] At least 25% by cost of structural framing lumber is FSC- or SFI-certified (or reclaimed). +1 pt per additional 25% (max 4 pts for fully certified/reclaimed framing).

  2. 02.

    [2 pts] Subfloor / sheathing is FSC-certified or reclaimed.

  3. 03.

    [1 pt each, max 3] Reclaimed material as a primary finish — flooring, doors, fixtures, cabinets, exterior siding, interior brick/stone.

  4. 04.

    [2 pts] Insulation is biobased (cellulose, hemp, wool, wood-fiber) OR carries a Cradle to Cradle (C2C) Bronze+ certification.

  5. 05.

    [1 pt each, max 3] Concrete mix design uses ≥ 30% supplementary cementitious materials (slag, fly ash, calcined clay) at the slab, foundation, OR exposed elements.

  6. 06.

    [2 pts] Project compiles Environmental Product Declarations (EPDs) for at least five major material categories.

  7. 07.

    [2 pts] At least three products in the project carry Cradle to Cradle Silver+ certification.

  8. 08.

    [1 pt] No tropical wood anywhere in the project (this is already required at Gold tier for new construction — point applies for retrofits and as a baseline confirmation).

  9. 09.

    [2 pts] Project documents a construction-waste diversion rate ≥ 75% (by weight) with hauler tickets or waste-audit report.

Exclusions

  1. 01.

    No use of tropical wood (matches the Gold-tier requirement).

  2. 02.

    No vinyl (PVC) flooring or wall coverings as a primary finish in occupied rooms.

  3. 03.

    No products on the Living Building Challenge Red List as primary finishes where a viable Red-List-free alternative exists.

Documentation

  1. 01.

    Materials submittal log listing each contributing product with category, cost, certification number, and source.

  2. 02.

    Certification documents (FSC chain-of-custody, C2C certificate, EPD PDFs) attached to the log.

  3. 03.

    Photos of reclaimed-material applications and certification labels at the source where available.

  4. 04.

    Construction waste tracking sheet + hauler tickets if claiming the waste-diversion points.

  5. 05.

    Tally sheet showing earned points across categories — verifier signs the ≥ 8 pt threshold.

Verification by tier

Evidence the project team submits at each certification tier. Cumulative — higher tiers include everything below unless noted otherwise.

  1. Certified

    Self-attestation
    • 01.

      Materials submittal log listing every contributing product with category, cost, certification number, and source — tally sheet showing earned points ≥ 8.

  2. Silver

    Documents + photos
    • 01.

      Certification documents (FSC chain-of-custody, C2C certificate, EPDs as PDFs) attached to the log.

    • 02.

      Photos of reclaimed-material applications and certification labels at the source where available.

  3. Gold

    Third-party test
    • 01.

      Construction waste tracking sheet + hauler tickets verifying waste-diversion ≥ 75% (where waste-diversion points are claimed).

    • 02.

      Third-party spot-audit of the materials submittal log by the GreenHome Inspector or a mindful MATERIALS reviewer.

  4. Platinum

    Post-occupancy verification
    • 01.

      Closeout audit at substantial completion confirming the as-installed materials match the submittal log (with a chain-of-custody trace for at least three high-cost line items).

Materials & Environmental Impact Required from Certified 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

Open full page →
Materials & Environmental Impact Required from Gold 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

Open full page →
Materials & Environmental Impact Required from Platinum 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

Open full page →
Materials & Environmental Impact Required from Certified 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.

Open full page →
Materials & Environmental Impact Required from Certified 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

Open full page →