Codes in six states and the District of Columbia accept certification to the Passive House Institute (PHI) standard as a way to comply, and Massachusetts requires Passive House for large multifamily buildings in 60 municipalities. Two cities and one state use it in zoning, and in Canada, British Columbia names PHI in its building code. This page sets out each one, how codes that accept it handle documents at permit and at occupancy, and what is changing.
On this page: Energy codes · How codes handle certification · Zoning and land use · Canada · Changing
Energy codes
The Massachusetts Specialized Code requires Passive House for large multifamily buildings. The other codes accept PHI certification as a way to comply.
| Where | Code | What PHI certification does |
|---|---|---|
| Massachusetts | Specialized Opt-in Code, 225 CMR 23 §C407.3 | Passive House is the required path for new multifamily over 12,000 sf; PHI certification meets it. Adopted by 60 municipalities (June 2026). |
| Stretch Code §C401.2.2; low-rise residential §R405 | A compliance path for any building, in 242 municipalities, with no thermal-bridge backstop calculation. | |
| Colorado | Denver Green Code §401.6.2, §701.7.2 | PHI certification meets the Green Code’s energy chapter, residential and commercial. |
| Boulder County BuildSmart | Homes over 3,000 sf must certify to one of four programs; Passive House is one (from July 2026). | |
| Illinois | Residential and Commercial Stretch Energy Codes | PHI-certified buildings are deemed to comply. In force for state-funded projects since January 2025 and open to any municipality. |
| New York | NYStretch-2020 §R408 | A residential path through PHI’s Low Energy Building Standard, adopted by at least 40 communities, New York City among them. |
| City and Town of Ithaca Energy Code Supplements | Design to PHI Passive House Classic meets the local supplement. | |
| Rhode Island | Residential Stretch Code §4.8.2 | An alternative path in the voluntary stretch code used for public projects. |
| Washington | State Energy Code §R407.3; Seattle Energy Code | A residential path through a PHI Low Energy Building certificate. |
| Washington, DC | DC Construction Codes §101.10.6.5, §101.10.7.7 | A net-zero path: PHI certification plus on-site solar, commercial and residential. |
How codes handle certification
| Where | At permit | At occupancy, or after |
|---|---|---|
| Massachusetts §C407.3.2.2 | A PHPP compliance report, the PHI-accredited Certifier’s statement that it matches the plans, and registration; or the Certifier’s design-stage assurance letter. | An as-built PHPP report with airtightness and ventilation test results and a consultant’s statement; or the final certification letter. If final certification fails, a near-Passive House path (§C407.3.2.3) still allows occupancy. |
| Denver §401.6.2 | Signed intent letter from a PHI-accredited certifier. | PHI final report before the certificate of occupancy. |
| Illinois stretch codes | Certification, plus the code’s mandatory provisions (and, for homes, an enclosure at least at 2009 IECC levels). | Certification. |
| Ithaca; Cambridge | Design to the criteria, documented by a certifier’s pre-certification letter (Ithaca) or PHPP results and a certified consultant (Cambridge). | Certification isn’t required. Cambridge requires on-site quality assurance by a trained verifier. |
| Washington §R407.3 | Statement from the Certifier. | PHI Low Energy Building certificate before the certificate of occupancy. |
| Washington, DC | Design to the PHI program, with on-site solar. | Evidence of PHI certification within 18 months of the certificate of occupancy. |
Zoning and land use
| Where | Ordinance or law | What PHI certification does |
|---|---|---|
| Cambridge, MA | Zoning Ordinance Art. 22 §§22.20–22.25 | The PHI Passive House program is one of the rating systems that meet the green building requirement for projects of 25,000 sf or more. |
| Somerville, MA | Master Planned Development overlay; Net Zero Ready density bonus | All-electric buildings certifiable to PHI meet the overlay’s sustainability requirement. With LEED Platinum, they also earn a lower lot area per unit: 875 sf, against 1,125–1,500 sf. |
| Washington | 2SHB 1183 (Chapter 139, Laws of 2025) | For buildings meeting passive house requirements: up to 8 in. of added wall insulation outside setbacks, floor area measured inside the walls, 8 in. of added height, no façade modulation, and, with exceptions, no parking minimums. |
Canada
| Where | Code or by-law | What PHI certification does |
|---|---|---|
| British Columbia | BC Building Code 2024 9.36.6.3(3), 10.2.3.3(3) | Deemed to comply at the top Step Code steps, modeled in the PHPP by a PHI-approved designer. |
| Vancouver | Zoning By-law §10.33 | Defines a zero emission building by PHI certification: up to 19% of floor area excluded, with height and yard relief, through 2030. |
| Building By-law; large buildings; Higher Buildings Policy | A compliance path for buildings of every size, and accepted for added height. | |
| Other BC cities | Richmond; New Westminster; Saanich | Richmond, 10% more floor area and the permit fee refunded; New Westminster, added density and height; Saanich, the certificate as energy label. |
| Toronto | Toronto Green Standard v4; development charge refund | Meets the Tier 2 and 3 energy measures, which earn a partial development charge refund. |
Changing
California’s AB 368 directs the Energy Commission to evaluate a Passive House path for Title 24 and report by July 1, 2028.
Incentives, tax credits, and finance for certified buildings are on Building Financial Incentives. Know of a code or ordinance that recognizes PHI certification and isn’t listed here? Tell us at info@passivehousenetwork.org.
Checked October 2026. Terms change yearly; check the linked source before relying on a figure.
