Laws & Rules

This is your gateway to the laws, existing rules, rules in development, and policies for L&I’s program regulating manufactured and mobile homes, food trucks, and other mobile or modular structures. Here you can learn about:

  • Applicable laws and rules.
  • New rules being developed.
  • How to get involved with the rulemaking process.
  • New policies the program develops.

If you have a question about a rule, law or policy, email us at FAS1@Lni.wa.gov.

Laws & rules

The state Legislature enacts laws regulating manufactured and mobile homes, food trucks, and other mobile or modular structures.

These laws are in chapters 43.22 and 43.22A of the Revised Code of Washington (RCW).

Agencies adopt rules to implement laws. Rules implementing the laws in chapter 43.22 and 43.22(a) are codified in the Washington Administrative Code (WAC) at Title 296-Chapter 49A, and 150C, 150F, 150I, 150M, 150P, 150R, 150T, and 150V.

The RCW and WAC are maintained and updated by the State Office of the Code Reviser.

If you receive an error message when referencing a link to a specific section of a WAC or RCW, try your search at the Washington State Legislative Search page.

For more information

Laws

Revised Code of Washington (RCW)
Code of federal regulations
Washington Administrative Code (WAC)

Contact us 

FAS1@lni.wa.gov
1-800-705-1411 Option 3

Mailing Address
Washington State Department of Labor & Industries
PO Box 44430
Olympia WA 98504-4430

Location
7273 Linderson Way SW
Tumwater WA 98501

Rule Development

When L&I officially announces a rule, it does so under law through permanent rulemaking, expedited rulemaking or emergency rulemaking changes to the Washington Administrative Code (WAC). Learn more about the rulemaking process and common rulemaking terms.

2022 emergency rulemaking
Plan review by licensed professionals

L&I adopted an emergency rule to speed plan review for modular buildings, among other structures on December 21, 2021, and extended the rule on April 19 and August 16. On December 13,  L&I filed another extension of that rule, which allows the use of licensed professionals in areas where L&I’s Factory Assembled Structures Program (FAS) requires plan review. 

The 120-day extension allows more time for the FAS Program to address the backlog of more than 900 design plans that still exists while developing permanent rules. 

The emergency rule also clarifies what a design plan submission must include and how to submit design plans for approval for commercial coaches and factory-built housing and commercial structures.

The "emergency rulemaking process" may be used when a rule is needed before the standard rulemaking process can be completed.

The changes affect rules under:

In all, the emergency changes allow for review and approval of design plans for recreational park trailers, recreational vehicles, and conversion vendor units by a licensed professional engineer, architect, or firm. The changes also clarify what a design plan submission must include and how to submit design plans for approval for commercial coaches and factory-built housing and commercial structures.

Unless extended, the emergency rule expires on April 12, 2023.

For more information about the process for design plans by licensed professionals, visit the "Modular & Other Structures" page.

Rulemaking Documents

2022 rulemaking
Plan review by licensed professionals

L&I is proposing changes that modify rules for design plan reviews by licensed professional engineers, architects, and firms for commercial coach trailers, factory-built housing and commercial structures, recreational park trailers, recreational vehicles, and conversion vendor units (food trucks and trailers).

 L&I filed emergency rules to address a backlog of design plans in the Factory Assembled Structures Program (FAS) (see above). This rulemaking considers the adoption of permanent rules.

The changes affect rules under:

L&I filed the proposed rules (CR-102) on February 28, 2023.

How to participate

Public comments on the proposed rules will be accepted through the end of the business day, on April 4, 2023. 

A public hearing on the proposed rules is scheduled for April 4, 2023 at 9 a.m. 

The public hearing will be a “hybrid” event, that is, people can attend in person, by telephone, or Zoom.

The public hearing will take place at L&I Headquarters building, 7273 Linderson Way SW, Tumwater, WA

You can also join either:
Zoom
Click here to join the meeting: 
https://lni-wa-gov.zoom.us/j/86477040744?pwd=aHlWbGt5WFcyMHlTbWlnK0VaVElvUT09

Passcode: FASPH@1!

Telephone
1-253-215-8782
Meeting ID: 864 7704 0744
Passcode: 87842912

You can provide testimony or written comments at the above hearing, or send written comments by 5 p.m. on April 4, 2023, to:

Alicia Curry
Email: Alicia.Curry@Lni.wa.gov
Department of Labor & Industries
Field Services & Public Safety Division
PO Box 4400, Olympia, WA 98504-4400
Fax: 360-902-5292

Rulemaking Documents
Notice of Intent 8/16/22

Proposed Rule Language 2/28/23

 Here’s what happens next

  • April 4: A public hearing on the proposed rules is scheduled.
  • April 11: The final rules (CR-103) are expected to be filed with the state Office of the Code Reviser.
  • April 11, 2023: The new rules are expected to take effect.

Rulemaking for new legislation 

During the 2019 legislative session, the state Legislature enacted laws affecting factory assembled structures. The changes included:

  • Requirements for energy efficiency.
  • Delegation of inspection duties.
  • Tiny houses.

These changes require L&I to engage in rulemaking.

During the 2019 legislative session, L&I separately filed a preproposal statement of inquiry (called a CR-101) (WSR 19-06-069, filed March 5, 2019). The preproposal would have adopted rules allowing for inspection and approval of manufactured building panels prior to shipment to a construction site within the state. The preproposal would also have made updates, clarifications, and housekeeping changes.

Instead of conducting two separate rulemakings - one to address legislative changes and one to consider a new rule - L&I has determined it is a better use of agency resources to consolidate all of the required changes into one rulemaking.

As a matter of procedure, the agency has withdrawn the preproposal. The agency instead has filed a new preproposal to consider changes to WAC chapter 296-150F related to:

  • Requirements for energy efficiency.
  • Delegation of inspection duties.
  • Tiny houses.
  • Inspection and approval of manufactured building panels prior to shipment to a construction site within the state.
  • Updates, clarifications, and housekeeping changes.

Rulemaking documents

For more information

Contact us 

FAS1@lni.wa.gov
1-800-705-1411 Option 3

Mailing Address
Washington State Department of Labor & Industries
PO Box 44430
Olympia, WA 98504-4430

Location
7273 Linderson Way SW
Tumwater WA 98501