Tiny Homes: Ontario vs San Bernardino
How do tiny homes rules compare between Ontario, CA and San Bernardino, CA?
San Bernardino has fewer restrictions than Ontario.
Ontario, CA
San Bernardino County
Foundation-built tiny homes qualify as ADUs under Gov Code 65852.2 in Ontario. Tiny homes on wheels are treated as RVs or park trailers and cannot be used as permanent dwellings on residential lots.
View full Ontario rules →San Bernardino, CA
San Bernardino County
Tiny homes on permanent foundations in San Bernardino are regulated as ADUs under CA Gov Code 65852.2. Tiny homes on wheels are treated as RVs and cannot be permanent dwellings outside approved parks.
View full San Bernardino rules →Key Facts Comparison
| Fact | Ontario | San Bernardino |
|---|---|---|
| Foundation tiny home | Legal as ADU under Gov 65852.2 | - |
| THOW (wheels) | Treated as RV or park trailer | - |
| Permanent THOW living | Not allowed on residential lot | - |
| ADU size cap | Up to ~1,200 sq ft per state | - |
| Permit | Ontario Building and Safety | - |
| Permanent foundation | - | Permitted as an ADU under Gov Code 65852.2 |
| ADU sizing | - | 850 to 1,200 sq ft with 16 ft height safe-harbor |
| Wheels/RV | - | Tiny home on wheels treated as RV; no permanent residency |
| Approved parks | - | RV parks or licensed mobilehome parks allowed for THOWs |
| Utilities | - | Must connect to approved water, sewer, and power as dwelling |
Highlighted rows indicate differences between cities.
Ontario FAQ
Can I live full time in a tiny home on wheels parked at my Ontario house?
No. A tiny home on wheels is classified as an RV, and using it as a permanent residence on a single-family lot violates the RV occupancy rules and zoning.
Can I build a foundation-based tiny home as an ADU?
Yes. A site-built tiny home on a permanent foundation is a legal ADU under Government Code 65852.2 and must be ministerially approved if it meets state ADU standards.
San Bernardino FAQ
Can I live full-time in a tiny home on wheels on my San Bernardino lot?
Generally no. Zoning and state housing law treat tiny homes on wheels as RVs, which cannot be occupied as permanent residences on single-family lots.
Is a foundation-built tiny home allowed?
Yes, as an ADU under Gov Code 65852.2, provided it meets ADU size, Title 24, smoke or CO alarm, and utility connection rules.
Are there any exceptions for shelter or homelessness?
State-sanctioned pilot projects and approved tiny home villages operate under specific statutes, but individual lots in San Bernardino are not open to THOW occupancy.
Compare other topics
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