The proposed bill aims to reduce embodied carbon emissions in buildings and building materials in Washington State by establishing new regulations and compliance pathways for construction projects. It mandates the state building code council to adopt rules that facilitate these reductions, particularly for new constructions, additions, and renovations of buildings over 100,000 square feet, excluding school district projects. The bill outlines three compliance paths: maintaining a significant portion of an existing structure, demonstrating reduced life-cycle stage emissions of covered products, or conducting a whole building life-cycle assessment. Additionally, the council is tasked with defining covered products, establishing reporting requirements, and ensuring that design professionals verify compliance with embodied carbon emissions calculations.

Furthermore, the bill introduces a public database for tracking embodied carbon emissions reductions and mandates the development of educational resources to support implementation. It sets a target for a 30% reduction in embodied carbon emissions by 2030, with incremental goals leading up to that date. The council is also required to report progress and findings from project audits every three years. Definitions related to embodied carbon emissions, life-cycle assessments, and the roles of design professionals are included to clarify the bill's provisions. Overall, the legislation seeks to enhance sustainability in the construction industry while providing a framework for accountability and compliance.