HB 1458 — Reducing embodied carbon emissions of buildings and building materials.

H-1446.1H-0489.1 SUBSTITUTE HOUSE BILL 1458 State of Washington 69th Legislature 2025 Regular Session By House Local Government (originally sponsored by Representatives Duerr, Doglio, Hunt, Mena, Berry, Reed, Ramel, Parshley, Peterson, Scott, Pollet, and Hill)Hill READRead FIRSTfirst TIMEtime 02/18/25.01/21/25.

Referred to Committee on Local Government.

In developing these standards, the state building code council shall consult with the appropriate state agencies, including the department of enterprise services, the department of commerce, the department of ecology, the University of Washington, an existing technical work group with relevant expertise, and other interested parties.

(2) The embodied carbon emissions reductions established in section 8 of this act shall apply to all new construction, additions, and renovations 50,000 square feet or larger of any building covered by the international commercial building code.

1 SHBHB 1458 (4)NEW ProjectsSECTION. covered under subsection (2) of this section may choose one of the following three paths to comply with the embodied carbon emissions reduction requirements:

(a) Maintaining an existing portion of a building structure and envelope pursuant to section 2 of this act;

(b) Demonstrating a reduction in A1 to A3 life-cycle stage emissions in covered products pursuant to section 3 of this act;

and (c) Demonstrating embodied carbon emissions reduction using a whole building life-cycle assessment pursuant to section 4 of this act.

NEW SECTION.

(1) Building projects that maintain at least 45 percent of an existing structure and envelope and do not add more than 50 percent to the total area comply with the embodied carbon emissions reductions requirements established in section 8 of this act.

(1)(a) AsAll an alternative to the requirements in section 2 or 4 of this act, all building projects must demonstrate, and require in the construction documents, that the life-cycle state A1 through A3 embodied carbon emissions of the covered products used, measured in terms of global warming potential for at least 90 percent of covered products and summed up at the project level, meets the goals established in section 8 of this act when compared to the project's summed industry average global warming potential.

To achieve this reduction, building projects must use project-specific material quantities and product and facility-specificfacility- specific environmental product declarations to demonstrate compliance.

p.(c) A building project's design professional of record shall update quantity and embodied carbon emissions calculations based on product and facility-specific environmental product declarations from procured products and attest that they are accurate and comply with the construction documents requirements to the best of the design professional's knowledge.

2 SHB 1458 (c) A building project's design professional of record shall update quantity and embodied carbon emissions calculations based on product and facility-specific environmental product declarations from procured products and attest that they are accurate and comply with the construction documents requirements to the best of the design professional's knowledge.

NEWp. SECTION.

2 HB 1458 NEW SECTION.

(1) As an alternative to the requirements in section 2 or 3 of this act, building projects may demonstrate the embodied carbon emissions reductions using a whole building life-cycle assessment as compared against a functionally equivalent reference building.

The reference building shall be of the same size, geographic location, function, type, and thermal performance.

(4) The design professional of record responsible for the embodied carbon calculations and reporting shall be specified in the p.architect of record construction documents.

3 SHB 1458 architect of record construction documents.

At minimum, the database must include basic information about the project,p. project area, which compliance pathway was selected, approximate location, primary structural system, primary building use, and how the project met the standards for the selected pathway.

3 HB 1458 project, project area, which compliance pathway was selected, and how the project met the standards for the selected pathway.

and (e) Provide checklists, templates, training, and other tools as needed to support implementation;implementation.

and (f) Provide a list of software that may be used to support compliance with section 4 of this act.

p.(3) "Global warming potential" means the potential climate change impact of a product or process as measured by a life-cycle assessment.

4 SHB 1458 (3) "Global warming potential" means the potential climate change impact of a product or process as measured by a life-cycle assessment.

(5) "Whole building life-cycle assessment" means a cradle to grave assessment covering life-cycle stages A-C as defined by the international organization for standardization standard 21931-1, excluding modules B6 and B7, or similarly robust whole building life- cycle assessment methods or whole life carbon assessment standards thatp. evaluate the environmental impacts of a building including, at a minimum, global warming potential.

4 HB 1458 that evaluate the environmental impacts of a building including, at a minimum, global warming potential.

(1) The state building code council shall convene an existingembodied technicalcarbon workemissions groupreductions withtechnical relevantadvisory expertisegroup establishedpursuant into RCW 39.116.05019.27.033 for the purpose of recommending modifications and limitations to the international building code adopted by Washington regarding embodied carbon emissions reductions standards for residential and nonresidential buildings.

(2) The technical advisory group shall, at minimum, consist of the following members:

(a) State agency representatives, ex officio;

(b) A representative from the commercial building industry;

(c) A representative from the residential building industry;

(d) An architect;

(e) A representative from an environmental organization;

(f) A local government building official;

(g) A person with expertise on water efficiency;

(h) A fire official;

(i) A mechanical engineer;

(j) A structural engineer;