WA HB1458

Requires 30% reduction in embodied carbon emissions for new construction, additions, and renovations of 50,000 square feet or larger under the 2030 state building code, using Carbon Leadership Forum 2023 baselines or comparable industry averages

Provides three compliance pathways: maintaining at least 45% of existing structure/envelope, demonstrating reduced life-cycle emissions in at least 90% of covered products using environmental product declarations, or completing a whole building life-cycle assessment compared to a reference building

Directs the State Building Code Council to adopt incremental embodied carbon standards in the 2027 and 2030 code cycles, with progress reports due December 31, 2028, and every three years thereafter

Requires the Department of Commerce to create and maintain a public database for reporting embodied carbon data, develop educational resources, and conduct random audits on 3% of projects annually

Mandates that design professionals of record calculate, verify, and attest to embodied carbon compliance, with calculations stamped and submitted with permit documents