HB 1353 Washington House · 2025-2026 Regular Session

Establishing a self-certification program for accessory dwelling unit project permit applications.

HB 1353 creates a program allowing cities in Washington to let registered architects self-certify that accessory dwelling unit (ADU) projects meet building code requirements, instead of requiring full city review. This directly affects homeowners building ADUs, architects who can self-certify, and cities that choose to adopt the program. Key provisions include mandatory random audits (at least 20% of applications yearly), penalties for failed audits (temporary suspension for first failure, permanent ban for second within 5 years), and requirements for architects to maintain insurance. Cities must also track and share audit results with a state database to prevent problematic architects from participating in other cities. The law aims to streamline ADU permitting while maintaining safety through oversight.
Bill status signed all 5 stages cleared
Introduction
Jan 2025
Committee Review
Mar 2025
House Passage
Mar 2025
Senate Passage
Mar 2025
Signed into Law
Apr 2025
Introduced Jan 16, 2025 Signed Apr 7, 2025
Maddy AI version diff · 2 comparisons

What changed between versions

Substitute Bill Substitute Passed Legislature · 3 edits
MINOR
The primary change is the addition of a formal Certification of Enrollment page, which officially documents that the bill passed both the House and Senate with specific vote counts and dates. This addition transforms the document from a draft version into the final, legally certified text ready for the Governor's signature and public filing.
TECHNICAL

Added a Certification of Enrollment page containing the official vote counts (94-1 in the House, 49-0 in the Senate) and dates of passage for both chambers.

Added a signature block for the Chief Clerk of the House of Representatives to certify the bill's authenticity.

Removed the draft bill number 'H-1331.1' and replaced it with the final title 'CERTIFICATION OF ENROLLMENT'.

Floor votes · Senate Mar 26, 2025 · House Mar 4, 2025

How they voted

510
Passed
Total votes 51
Mar 26, 2025
D Democratic31
31 Yea
100% Yea
R Republican20
20 Yea
100% Yea
Vote distribution
All Yea All Nay Mixed No data
Full legislative history

Actions timeline

Total actions
25
Key actions
10
Committee
6
Apr 7, 2025
Signed into law
Governor signed.
executive
Mar 31, 2025
Upper · Passed
President signed.
upper
Mar 31, 2025
Lower · Passed
Speaker signed.
lower
Mar 26, 2025
Senate · Passed
Senate Vote: pass (51-0)
senate
Mar 19, 2025
Upper · Passed
HSG - Majority; do pass.
upper
Mar 19, 2025
Upper · Passed
Executive action taken in the Senate Committee on Housing at 1:30 PM.
upper
Mar 14, 2025
Upper · Passed
Public hearing in the Senate Committee on Housing at 10:30 AM.
upper
Mar 4, 2025
House · Passed
House Vote: pass (96-1-3)
house
Feb 13, 2025
Committee
Referred to Rules 2 Review.
lower
Feb 12, 2025
Lower · Passed
Executive action taken in the House Committee on Local Government at 8:00 AM.
lower
Feb 4, 2025
Lower · Passed
Public hearing in the House Committee on Local Government at 10:30 AM.
lower
1 primary · 4 co-sponsors

Sponsors