Research disclaimer: This guide is based on our best research but zoning rules change frequently. Always confirm with the city or county before purchasing.
The Basics
What Is a Park Model RV?
Park model RVs are legally classified as recreational vehicles, built to the ANSI 119.5 standard. They follow RV rules rather than residential building codes, which typically means fewer permitting steps than a site-built ADU - while still needing to comply with local zoning.
Please note - proper terminology matters when talking to city zoning
"Tiny home" is a broad informal term that can mean anything from a shed to a manufactured home depending on who you ask. When speaking with any city or county official, always use the specific term: "Park Model RV built to ANSI 119.5 code." Park model RVs are a federally defined category with a national standard - using the right term points officials to the correct code section and gets you an accurate answer.
Designed on a single chassis and mounted on wheels
Certified to ANSI A119.5 - built and inspected to that standard
Maximum 400 square feet in setup mode (excluding porch and loft)
Wheels can be removed for placement if a jurisdiction requires it - and reinstalled later
Park Model RV Tiny Home Basics
How to Check Your Zoning
We put together sample messages below that you can copy, modify, and send directly to your local city or county planning department. You do not need to share your exact address - just your zoning designation (for example: R-5, RR-10, or MUA). Your zoning designation can usually be found on your county assessor's website or by searching your address in your county's GIS map tool.
We included an initial inquiry template and a follow-up response for common situations where they need more information or push back. Modify these based on your specific property and needs. If you have further technical questions after speaking with your city, you can reach out to NW Tiny Homes and we can help point you in the right direction.
Note on permanent foundations: If a jurisdiction requires a permanent foundation, a professional installation company would typically use a system called diamond piers - engineered cement blocks driven to bearing soil via steel posts, installed in under two days with minimal excavation. This is an approved alternative to traditional poured concrete stem wall foundations and has been accepted in multiple Washington jurisdictions. Learn more at Tiny House Alliance USA or visit diamondpiers.com.
If your planning department wants more detail - what a park model RV is, how it is regulated, the Lynnwood diamond pier precedent, and answers to common code questions - send them this PDF.
Copy and send to your local planning departmentSubject: Zoning Questions for Park Model RV Placement
Hi there,
I am considering placing a Park Model RV built to ANSI 119.5 code on my property. The unit is under 400 square feet and RVIA certified. (Washington properties: also note the unit carries a Washington State L&I insignia.)
Can you help me confirm the following:
Is an occupied Park Model RV allowed in my zoning district?
Are there any setback or placement requirements for park model RVs?
Is a permit required for delivery or utility connections (water, sewer, electric)?
Beyond utility connections, are there any other permits, inspections, or approvals required to place a park model RV on this property?
Are there any time or occupancy limits on how long someone can live in a park model RV on private property?
Send this if they say no or need more informationSubject: Follow-Up - Park Model RV Foundation Option
Hi [name],
Thank you for your response. I have a couple of follow-up questions.
The unit I am considering can be placed on a permanent engineered foundation if that is required. The foundation system is called diamond piers - engineered cement blocks driven to bearing soil, used as an approved alternative to traditional poured concrete foundations.
Would placement on a permanent foundation change how the unit is classified or permitted?
Is there a specific permit path for a park model RV on a permanent foundation?
I am happy to provide additional technical documentation if helpful. Thank you again.
📍
Coverage: This guide includes the 100 largest cities in Oregon and Washington, plus all 75 counties. If your city is not listed, use the email templates above to reach your local planning department - the same questions apply everywhere.
Research by Location
Browse Zoning Laws by County and City
Select your state, then search by county or city name. Every county in Oregon and Washington researched. Cities listed separately within each county.
Choose your state to see zoning laws
Easy Path
Clear laws allow it
Defined permit process or explicit ordinance. City or county has said yes in writing.
Mixed
Varies by city
Some cities within this county allow it. Others restrict or need a call. Check city-level entries.
Verify First
Call before assuming
No formal permit path confirmed yet. Temporary use, hardship, or foundation paths often work.
Restricted
Explicitly limited
Code explicitly restricts or prohibits RV dwelling. Read the notes for any available exceptions.
Search your county or city
36 counties
No counties or cities match your search.
Easy PathClear Legal Path Exists4 counties
MixedSome Cities Allow - County Itself Varies0 counties
Verify First
Call Before Assuming Anything
Temporary use, hardship, or foundation paths often work
24countiesTap to expand ↓
Restricted
Explicitly Restricted - Read Notes for Exceptions
Limited paths may still exist - read the notes carefully
8countiesTap to expand ↓
Zoning confirmed? Let's talk.
Once your city or county has confirmed placement is possible, come see us. We'll help you find the right model, walk through financing, and get you on the delivery schedule.
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For all zoning questions, please use the templates above to contact your local planning department directly. We're not able to advise on specific zoning situations - your city or county planner is the right person for that.
