HB 1458 Washington House · 2025-2026 Regular Session

Reducing embodied carbon emissions of buildings and building materials.

HB 1458 requires large new construction, additions, and renovations (50,000+ square feet) to reduce embodied carbon emissions from building materials. It offers three compliance paths: reusing 45% of existing structures, demonstrating a 90% reduction in emissions for covered materials, or conducting a whole-building life-cycle assessment. Projects must report data through a public database managed by the Department of Commerce, including material choices and compliance methods. The law applies to all covered projects under the International Building Code and mandates verification by licensed design professionals.

Issues: ✓ Energy ✓ Environment

Bill status in committee 1 of 4 stages cleared

Introduction

Jan 2026

Committee Review

Floor Vote

Governor

Introduced Jan 12, 2026 Last action Jan 12, 2026

Maddy AI version diff · 2 comparisons

What changed between versions

Substitute Bill → Second Substitute Bill · 5 edits

MODERATE

This bill was amended to shift its administrative oversight from local government to the capital budget, expand the size threshold for mandatory carbon reporting from 50,000 to 100,000 square feet, and exclude school district construction from these requirements. Additionally, the legal chapter for data reporting was updated to ensure consistency with new state statutes.

Scope change

The bill's applicability was narrowed by raising the minimum project size from 50,000 to 100,000 square feet and explicitly exempting school district construction projects from the embodied carbon reduction mandates.

SCOPE

Increased the minimum project size requirement from 50,000 to 100,000 square feet for new construction and renovations to trigger embodied carbon reporting.

ELIGIBILITY

Added a specific exemption for school district construction projects, meaning they are no longer subject to the bill's carbon reduction rules.

ADMINISTRATIVE

Changed the bill's sponsorship category from 'House Local Government' to 'House Capital Budget' and updated the reading date.

ENFORCEMENT

Updated the chapter reference for the new data reporting section from 43.30 RCW to 43.330 RCW.

TECHNICAL

Corrected a citation for the technical work group from RCW 39.116.050 to RCW 19.27.033.

Bill → Substitute Bill · 9 edits

MAJOR

This bill was amended to clarify its applicability to the broader International Building Code rather than just commercial buildings, and to provide building owners with three distinct compliance options: maintaining existing structures, reducing emissions in specific material stages, or using whole-building life-cycle assessments. The changes also expand the required data reporting to include more specific project details and add a list of approved software tools to the public guidance website.

Scope change

The bill's scope was broadened to apply to all buildings under the International Building Code, not just commercial buildings, and added a specific area limit for projects maintaining existing structures.

SCOPE

Expanded applicability from the International Commercial Building Code to the broader International Building Code to include more building types.

ELIGIBILITY

Added a new compliance pathway allowing projects that maintain at least 45% of an existing structure to comply, provided they do not increase the total area by more than 50%.

REQUIREMENT

Added a third compliance option requiring whole-building life-cycle assessments compared against a functionally equivalent reference building.

Updated the definition of covered products in the life-cycle stage reduction option to explicitly include 'state' A1 through A3 emissions.

Modified the technical advisory group requirement to utilize an existing state technical work group rather than convening a new group.

Updated reporting requirements to allow whole-building life-cycle assessment results as an alternative to product-specific declarations in the 2024 code cycle.

DEFINITION

Adjusted the definition of 'Whole building life-cycle assessment' to exclude specific modules (B6 and B7) from the required scope.

ADDED

Added a requirement for the public database to include specific project details such as approximate location, primary structural system, and primary building use.

TECHNICAL

Added a requirement for the public guidance website to provide a list of software tools that can be used to support compliance.

Floor votes

How they voted

No floor votes recorded yet.

Full legislative history

Actions timeline

Total actions

Key actions

Committee

Jan 12, 2026

Introduced

By resolution, reintroduced and retained in present status.

lower

Feb 27, 2025

Committee

Referred to Appropriations.

lower

Feb 26, 2025

Lower · Passed

Minority; do not pass.

lower

Feb 26, 2025

Lower · Passed

Executive action taken in the House Committee on Capital Budget at 9:00 AM.

lower

Feb 25, 2025

Lower · Passed

Public hearing in the House Committee on Capital Budget at 9:00 AM.

lower

Feb 18, 2025

Committee

Referred to Capital Budget.

lower

Feb 14, 2025

Lower · Passed

Minority; do not pass.

lower

Feb 14, 2025

Lower · Passed

Executive action taken in the House Committee on Local Government at 10:30 AM.

lower

Feb 5, 2025

Lower · Passed

Public hearing in the House Committee on Local Government at 8:00 AM.

lower

1 primary · 11 co-sponsors