The decision library / Original research checklist
Can I put a tiny home on my land? Get these six answers first.
“It depends” is true and useless. Here is what it depends on, who decides each piece, and what to write down so the answer holds.
Zoning decides what may be placed where. The building department decides how it must be built. Both must say yes to the same home on the same lot.
| Question | Who answers it | What to record |
|---|---|---|
| 1. What is the parcel zoned, and is a dwelling (or a second dwelling) allowed there? | Planning / zoning office | Zone code, permitted uses, date, name of the person you spoke to |
| 2. Does the jurisdiction treat a home on wheels as a dwelling, an accessory dwelling, or a vehicle? | Planning / zoning office | The ordinance section, in writing |
| 3. Which building standard must the home meet, and who inspects it? | Building department | Code edition; whether the tiny-house appendix is adopted; inspection path |
| 4. Is there a minimum dwelling size, and does a loft count? | Building department and zoning | Square-footage rule and what it excludes |
| 5. What water, wastewater and power connections are required before occupancy? | Environmental health; utility provider | Septic or sewer requirement; well or service availability; distances |
| 6. What setbacks, separations and addressing apply to a second unit? | Planning; fire authority | Setback distances; separation from other structures; address process |
Why there are two offices.
The International Code Council’s March 2023 guide, Navigating Certification and Regulation of Tiny Houses, separates the two cleanly: “building codes provide criteria on how to build, zoning and land use policies address what and where to build,” and zoning “is largely developed at the sub-national level (states or localities).” A yes from one office is not a yes from the other. Questions 1, 2 and 6 belong to planning; questions 3 and 4 belong to the building department; question 5 usually involves a third.
Which standard your home is built to decides the whole conversation.
Most of the confusion comes from one fact: a home with wheels can be built to a recreational-vehicle standard, which treats it as a temporary dwelling, or to the residential building code, which treats it as a permanent one. California’s housing department spelled this out for its own building officials in Information Bulletin 2016-01: a tiny home there must be approved as one of a manufactured home, a residential-code dwelling, factory-built housing, a recreational vehicle, a park trailer or a camping cabin. The bulletin notes that RVs “are not intended for occupancy as a permanent dwelling,” that an RV has “less than 320 square feet of internal living room area” and “400 square feet or less of gross area,” and that a manufactured home on a permanent chassis is “320 or more square feet.” Other states draw the lines differently, but every state draws them. Ask question 3 before you buy the home, not after.
A real ordinance, so you know what “yes” looks like.
Placer County, California publishes its rules for moveable tiny houses. There, a moveable tiny house is a separate living unit “no larger than four hundred (400) square feet,” mounted on a wheeled trailer chassis, “Licensed and registered with the California Department of Motor Vehicles” or with the state housing department, allowed as an accessory dwelling unit in listed zones with a zoning clearance, required to connect to approved water and sewage disposal, kept at least four feet from a lot line and “at least ten (10) feet from any other structures on the premises,” with its undercarriage “concealed from view.” The county notes its amendments were updated in February 2026 to follow state ADU changes effective January 1, 2026. Checked October 27, 2026. Your county’s answer will differ; its shape, an ordinance with a size cap, a registration path, a permitted zone list, utility conditions and separations, is what to look for.
Minimum size is a local rule with exceptions.
Where the residential code’s tiny-house appendix has been adopted, it defines a tiny house as “a dwelling that is 400 square feet (37 m²) or less in floor area excluding lofts” and relaxes ceiling, stair and loft rules for that category (2021 Seattle Residential Code, Appendix AQ). Where it has not been adopted, ordinary habitable-room minimums apply, and some zoning codes add their own minimum dwelling size on top. Ask question 4 as two questions: the building code’s minimum and the zoning minimum.
Take three questions into your next call.
- May I occupy this specific home, built to this specific standard, full time on this specific parcel, and will you put that in writing?
- What must exist on the lot before the occupancy permit or final inspection: septic, well or service, address, access?
- If the answer is no today, what is the variance or permit path, how long does it take, and what does it cost at each step?
Record every answer with the date and the person’s name. Rules change; a dated note of what you were told is worth more than a memory of it. The planner’s siting checklist has a place for each of these.
Put the method to work
Make the next decision yours.
The free planner’s siting checklist keeps your eight topics, authority contacts and source references beside your budget. Once the answers point to a home, the wheels versus foundation guide shows what each path adds to the cost lines.