Concerning city and town permitting of kit homes.

2023-2024 Regular Session Introduced by Mark Mullet and 2 co-sponsors

Gives cities power to permit kit homes under 800 sq ft under local fire and building rules, exempting them from the state Building Code while preserving factory inspections.

By resolution, returned to Senate Rules Committee for third reading.

SB 5657 — Concerning city and town permitting of kit homes

Status snapshot: Returned to Senate Rules Committee for third reading (by resolution 03/07/2024). Passed the House (3rd reading) 02/13/2024 (49–0). (Note: a different bill number SB 5657 appears in 2025 with unrelated subject matter; this summary covers the kit‑homes bill from the 2023–2024 legislative activity.)

Purpose / Intent

The bill aims to expand and expedite low‑cost housing options by creating a limited exemption from the State Building Code for small “kit homes,” allowing incorporated cities and towns to permit them under local permitting and fire‑safety rules. The legislature frames the change as a tool to simplify and streamline building inexpensive, affordable homes.

Key provisions

Adds a new definition of “kit homes” and amends RCW 19.27.015 (chapter 19.27 RCW — factory‑built housing provisions).

Defines “kit homes” (engrossed substitute version):

Structures designed and constructed in a factory to life, health, and safety standards as outlined in the U.S. Department of Housing and Urban Development (HUD) code; and
Inspected at the factory by the Department of Labor & Industries (L&I) for in‑state factories, or inspected by the functional equivalent of L&I for out‑of‑state factories.

Exempts kit homes under 800 square feet from chapter 19.27 RCW (the State Building Code provisions for factory‑built housing) when placed:

On private property; or
On public property within a planned unit development (PUD).

Exemption is conditional: such kit homes remain subject to permitting by incorporated cities or towns and applicable local fire safety regulations.

Effective date: 90 days after adjournment of the legislative session in which the bill is passed.

Fiscal: No appropriation; fiscal note requested (02/19/2024).

Who would be affected

Homebuyers and homeowners seeking small, factory‑assembled kit homes (≤ 800 sq ft).

Kit‑home manufacturers (in‑state factories remain subject to L&I inspection; out‑of‑state factories must have an equivalent inspection).

Incorporated cities and towns: gain primary permitting responsibility for these small kit homes and enforce local fire‑safety rules.

Department of Labor & Industries: retains a role for in‑state factory inspections and certification/inspection equivalency determinations for out‑of‑state factories.

Potentially county governments and other state building code enforcement agencies (scope of state code authority reduced with respect to these homes).

Procedural / timeline notes

Originated in the Senate State Government & Elections Committee (2023).

Committee hearings and executive action occurred in 2023–2024; the bill saw floor amendments and passed the House (02/13/2024).

By resolution, the bill was returned to Senate Rules Committee for third reading (03/07/2024).

If enacted, the law would take effect 90 days after adjournment of the session in which it is passed.

Practical implications to consider

Shift of regulatory authority from statewide code application (chapter 19.27) to local permitting for small kit homes could speed deployment but raise questions about uniformity of standards and oversight.

The bill preserves factory inspection requirements (L&I or equivalent), and local fire regulations still apply; zoning, land‑use, and other local requirements may continue to affect siting and installation.