California · 2025 CBC context
Tiny Home Regulations in California
County guide for park models, THOWs, and ADU pathways
California is broadly friendly to tiny living, but permission almost always turns on local zoning, building codes, and whether the unit is site-built, foundation-mounted, or a park model / tiny home on wheels (THOW). Use this guide to orient, then confirm with your city or county before you buy or place a unit.
Authored by the doihave.space Regulations Expert. Pre-written cited briefing — not generative AI legal advice. Role: Regulations briefing agent.
Building code baseline
Many jurisdictions follow the 2025 California Building / Residential Code (effective statewide January 1, 2026; Appendix AQ (Tiny Houses) where adopted). Typical permanent-dwelling minima include a ceiling height of 7 ft 6 in, one habitable room of at least 120 sq ft, and at least 70 sq ft net floor area for each additional habitable room. Local amendments and ADU ordinances can be stricter or more specific.
- Ceiling height
- 7 ft 6 in
- Primary room
- ≥ 120 sq ft
- Additional rooms
- ≥ 70 sq ft each
Are park models the same as tiny homes?
Park models are a common form of tiny home on wheels (THOW). Because they sit on a chassis, many localities do not treat them as permanent dwellings unless they meet RVIA/ANSI standards, sit in a permitted park, or are placed on an approved foundation and used as an ADU. California often allows THOWs as ADUs where local ordinances expressly authorize moveable tiny houses.
Full-time occupancy rules vary by county. Some areas allow park models only in RV / special occupancy parks, some allow them as ADUs once wheels/tongue are removed and utilities are permitted, and some prohibit THOWs as permanent residences entirely.
Where THOWs are allowed as permanent residences or ADUs, jurisdictions commonly require ANSI A119.5 compliance, DMV registration, size limits for highway movement, and skirting or residential exterior appearance.
What counties allow tiny houses?
Nearly every California county allows some form of tiny home. The details—especially for park models—vary. Expand a county for a short summary and official links.
Alameda CountyExpandCollapse
Favorable for tiny homes generally. Units are commonly capped around 400 sq ft of floor area excluding lofts; minimum floor area may be set case-by-case by planning staff.
Park models / THOW: Park-model / THOW rules are not always explicit—confirm with county or city staff before relying on wheels-on occupancy.
Oakland
Allows both foundation tiny homes and tiny homes on wheels through the city’s vehicular residential / THOW pathway. A permit is required.
Alpine CountyExpandCollapse
Allowed when meeting California Building Code minima (ceiling height, 120 / 70 sq ft habitable rooms).
Park models / THOW: Park models for permanent residence are typically limited to designated mobile home or special occupancy parks.
Calaveras CountyExpandCollapse
Colusa CountyExpandCollapse
Site-built / code-compliant tiny homes are permitted under 2022 CBC minima.
Park models / THOW: Allowed in mobile home / special occupancy parks. Also allowed as ADUs when utilities are county-approved under permit, wheels and tongue are removed, the unit sits on an approved foundation, the exterior reads as a dwelling (not an RV), and matching skirting is installed.
Del Norte CountyExpandCollapse
El Dorado CountyExpandCollapse
Adopted California Building Code editions with the same core habitable-room minima (≈7 ft ceilings, 120 / 70 sq ft rooms).
Park models / THOW: Exact park-model permanence rules are unclear—confirm locally.
Fresno CountyExpandCollapse
Publishes a dedicated tiny-home bulletin. Typical criteria include a minimum around 100 sq ft, ANSI 119.2 or 119.5 compliance, towable (not self-propelled), detached living with cooking/sleeping, and a conventional building appearance.
Park models / THOW: County guidance is comparatively park-model friendly when bulletin criteria are met. The City of Fresno generally follows the same handout.
Humboldt CountyExpandCollapse
Allows tiny homes and moveable tiny houses as permanent ADUs in inland areas. Also allowed as permanent residences in manufactured-home or special occupancy parks / villages.
Park models / THOW: Moveable units must comply with ANSI A119.5.
Imperial CountyExpandCollapse
Title 9 Division 10 recognizes tiny homes that meet California Building Code requirements, including RVs, manufactured / park models, modular, and site-built dwellings.
Park models / THOW: Park models are expressly contemplated in the ordinance framework.
Inyo CountyExpandCollapse
Tiny homes fall within the dwelling-unit definition when they comply with the California Building Code.
Kern CountyExpandCollapse
Follows 2022 CBC habitable-room minima for tiny homes. Bakersfield generally mirrors county building requirements.
Park models / THOW: Park models for permanent living are typically limited to designated RV or special occupancy parks.
Kings CountyExpandCollapse
Adopted California Building Code standards that allow code-compliant tiny homes.
Lake CountyExpandCollapse
Allows tiny homes under 2022 CBC standards.
Park models / THOW: Permanent park-model status is unclear—verify with Community Development.
Lassen CountyExpandCollapse
Uses 2022 CBC minima (≈7 ft ceiling, 120 / 70 sq ft rooms) for tiny homes.
Park models / THOW: Confirm park-model permanence with Planning & Building Services.
Los Angeles CountyExpandCollapse
Unincorporated Los Angeles County implements 2022 CBC room minima and expressly addresses moveable tiny houses as permanent ADUs. Incorporated cities have their own ADU ordinances.
Park models / THOW: Typical unincorporated THOW criteria include DMV licensing/registration, ANSI A119.5, not self-propelled, highway size limits, and roughly 150–430 sq ft.
Los Angeles
The City of Los Angeles allows ADUs and movable tiny houses as ADUs under LAMC and state ADU law. A city permit is required.
Movable tiny houses must be DMV-registered, ANSI 119.5 or NFPA 1192 certified, not self-propelled, and typically 150–430 sq ft. Confirm current LADBS standards before delivery.
Long Beach
Long Beach allows code-compliant ADUs under city building and planning standards. Confirm current ADU submittal rules with Long Beach Development Services.
THOW permanence is not always the same as a foundation ADU — confirm with Long Beach Building & Safety.
Madera CountyExpandCollapse
Follows 2022 CBC-friendly room minima for tiny living.
Park models / THOW: Park-model permanence is unclear—confirm with Building.
Marin CountyExpandCollapse
Adopted 2022 CBC standards supportive of code-compliant tiny homes.
Park models / THOW: THOW permanence is unclear—ask Building.
Mariposa CountyExpandCollapse
Mendocino CountyExpandCollapse
2022 CBC adopted; tiny homes allowed when room/height minima are met.
Park models / THOW: Likely follows statewide park rules—verify before delivery.
Merced CountyExpandCollapse
Follows 2022 CBC for tiny homes.
Park models / THOW: Permanent residence outside RV / special occupancy parks appears limited—confirm locally.
Modoc CountyExpandCollapse
Uses an older (2019) CBC edition with larger habitable-room minima (often cited as ≈220 / 100 sq ft).
Park models / THOW: May be permitted—confirm with Building & Safety.
Mono CountyExpandCollapse
2022 CBC adopted with 120 / 70 sq ft room minima.
Park models / THOW: Stance unclear—consult local officials.
Napa CountyExpandCollapse
Likely allows code-compliant tiny homes under 2022 CBC.
Park models / THOW: RVs may be treated similarly to mobile homes for full-time living inside designated parks.
Nevada CountyExpandCollapse
As of early 2025, the county allows tiny homes / THOWs under its updated ordinance pathway.
Orange CountyExpandCollapse
Follows 2022 CBC (7 ft 6 in ceiling, 120 / 70 sq ft rooms). Cities adopt local ADU ordinances on top of that floor.
Irvine
Irvine allows ADUs and JADUs on residential lots under the municipal zoning ordinance, with ministerial review. A city permit is required.
Moveable tiny houses are not automatically ADUs; confirm Irvine’s current ordinance before wheels-on occupancy.
Anaheim
Anaheim similarly allows CBC-compliant tiny homes as dwellings where zoning and ADU rules are met.
Placer CountyExpandCollapse
Allows both conventional tiny homes and park-model / THOW pathways. Review the county’s Tiny Homes page for current criteria.
Plumas CountyExpandCollapse
Allows tiny homes under published county guidance.
Park models / THOW: THOWs are generally not allowed as permanent residences; campground / RV park use may still be viable.
Riverside CountyExpandCollapse
Allows tiny homes that comply with 2022 CBC including Appendix AQ.
Sacramento CountyExpandCollapse
Allows tiny homes meeting 2022 CBC standards.
Park models / THOW: Wheeled units typically need a permanent foundation and local code compliance. The City of Sacramento similarly allows tiny homes / park models on permanent foundations or in designated parks.
Sacramento
The City of Sacramento allows tiny homes and park models that meet building-code and ADU standards, typically on a permanent foundation or in a designated park.
Wheeled units typically need a permanent foundation and local code compliance before occupancy.
San Benito CountyExpandCollapse
Specific tiny-home legislation: roughly 150–400 sq ft; wheeled units limited to about 14 ft width when towed; skirting required once placed; ANSI A119.5 for park models.
San Bernardino CountyExpandCollapse
Allows CBC-compliant tiny homes.
Park models / THOW: THOWs generally not permitted as permanent residences; short-term / lodging use may be a separate path.
San Diego CountyExpandCollapse
Unincorporated San Diego County follows 2022 CBC for tiny homes. Confirm county versus city jurisdiction before relying on City of San Diego bulletins.
San Diego
The City of San Diego allows ADUs and JADUs under the municipal code. A building permit is required; coastal overlay lots may also need a Coastal Development Permit.
The city publishes a Movable Tiny House bulletin (IB-403) for permanent THOW use as an ADU pathway — confirm current IB-400 / IB-403 standards with Development Services.
San FranciscoExpandCollapse
Allows tiny homes that meet 2022 CBC standards. Park models for permanent residence are typically limited to designated settings under statewide rules.
Park models / THOW: Confirm with SF Planning / DBI for ADU or park pathways.
San Joaquin CountyExpandCollapse
2022 CBC adopted for tiny homes.
Park models / THOW: Park models generally need a designated park location.
San Luis Obispo CountyExpandCollapse
2022 CBC allows tiny homes.
Park models / THOW: Allowed on a permanent foundation or in designated RV / special occupancy parks. Review the county’s movable tiny house ADU materials.
Santa Barbara CountyExpandCollapse
Allows tiny homes under 2022 CBC.
Park models / THOW: Allowed on permanent foundation or in designated mobile home / RV / special occupancy parks.
Santa Clara CountyExpandCollapse
Allows tiny homes and park models as ADUs under 2022 CBC room minima. San Jose similarly focuses on ADU pathways.
Park models / THOW: Park models as ADUs typically require ANSI A119.5 compliance.
San Jose
San Jose allows tiny homes through ADU pathways. Confirm current Development Services standards and permits before placing a unit.
Park models as ADUs typically require ANSI A119.5 compliance and local authorization.
Santa Cruz CountyExpandCollapse
Allows tiny homes and THOWs. County pages cover THOW permits and Vehicle License Fee considerations.
Shasta CountyExpandCollapse
Stricter path: often cites 2019 CBC with larger room minima (≈220 / 100 sq ft) and a practical floor near 400 sq ft.
Park models / THOW: Human habitation of park models typically limited to RV parks or campgrounds.
Sierra CountyExpandCollapse
2022 CBC allows tiny homes.
Park models / THOW: RVs, travel trailers, and mobile homes are generally limited to temporary dwelling use.
Siskiyou CountyExpandCollapse
Allows CBC-compliant tiny homes under 2022 standards.
Park models / THOW: Stance unclear—contact Building or Planning.
Solano CountyExpandCollapse
Allows tiny homes under 2022 CBC rules.
Park models / THOW: Confirm permanence with Building & Safety.
Sonoma CountyExpandCollapse
Tiny homes are primarily framed as temporary dwellings, with cottage-housing / foundation pathways for more permanent clusters.
Stanislaus CountyExpandCollapse
2022 CBC compliance is the baseline for likely approval.
Sutter CountyExpandCollapse
Allows tiny homes meeting CBC room/height minima (7 ft 6 in, 120 / 70 sq ft).
Park models / THOW: Park models limited to established RV parks operating with a state permit.
Tehama CountyExpandCollapse
Follows 2022 CBC Appendix AQ for tiny homes (7 ft 6 in, 120 / 70 sq ft).
Park models / THOW: Park models limited to designated parks.
Trinity CountyExpandCollapse
2022 CBC adopted; code-compliant tiny homes are allowed.
Tulare CountyExpandCollapse
Allows tiny homes under Appendix AQ of the 2022 California Residential Code.
Tuolumne CountyExpandCollapse
2022 CBC: 7 ft 6 in ceiling, 120 sq ft primary room, 70 sq ft additional rooms.
Ventura CountyExpandCollapse
Tiny homes allowed when they meet 2022 CBC room/height minima.
Park models / THOW: Full-time park-model occupancy is generally not permitted; RV park recreational use may still apply.
Yolo CountyExpandCollapse
Uses 2019 CBC-style larger room minima (≈220 / 100 sq ft) for tiny homes.
Park models / THOW: Unclear—confirm with Building Inspection Services.
Yuba CountyExpandCollapse
Allows tiny homes under 2019 CBC-style room minima (≈220 / 100 sq ft).
Park models / THOW: RVs, travel trailers, and park models are not permitted as permanent residences; short-term rental use may be a separate track.
Official resource directoriesCounty planning links and major city ordinances
County resource directory
Direct links to planning, building, and tiny-home materials.
- Alameda County — Code of Ordinances
- Alameda County — Government services
- Alpine County — ADU information sheet
- Alpine County — Tiny home requirements (PDF)
- Calaveras County — Planning
- Calaveras County — Building
- Colusa County — Community Development
- Colusa County — Zoning code
- Contra Costa County — Building regulations
- Contra Costa County — Code Enforcement
- Del Norte County — Planning
- Del Norte County — ADU FAQs
- El Dorado County — Planning & Building
- Fresno County — Building Safety
- Humboldt County — Tiny House Fact Sheet
- Humboldt County — Planning & Building
- Imperial County — Building Division
- Imperial County — Title 9 Div 10 (PDF)
- Inyo County — Building & Safety
- Kern County — Code of Ordinances
- Kings County — Community Development Agency
- Lake County — Community Development
- Lassen County — Planning & Building
- Los Angeles County — Accessory Dwelling Units
- Madera County — Building Division
- Marin County — Building Code
- Mariposa County — Planning
- Mendocino County — Planning & Building
- Merced County — Planning
- Modoc County — Building & Safety
- Mono County — Building regulations
- Napa County — Planning, Building & Environmental Services
- Nevada County — THOW ordinance notice
- Orange County — Development Services
- Placer County — Tiny Homes
- Plumas County — Tiny House Information Guide
- Riverside County — Building & Safety
- Sacramento County — Land Use Regulation Library
- San Benito County — Tiny Homes (AmLegal)
- San Bernardino County — Land Use Services
- San Diego — Movable Tiny House bulletin
- San Francisco — Department of Building Inspection
- San Francisco — Planning
- San Joaquin County — Community Development
- San Luis Obispo County — Movable Tiny Houses
- Santa Barbara County — Planning & Development
- Santa Clara County — ADU handbook
- Santa Cruz County — Tiny Homes on Wheels
- Shasta County — Building Division
- Sierra County — Planning
- Siskiyou County — Planning
- Solano County — Building & Safety
- Sonoma County — Tiny Houses
- Stanislaus County — Planning
- Sutter County — Planning & Zoning
- Tehama County — Building & Safety
- Trinity County — Departments
- Tulare County — Planning & Building
- Tuolumne County — Building Division
- Ventura County
- Yolo County — Building Services
- Yuba County — Building Department
Major cities
City rules can differ from the surrounding county—check both.
- Anaheim — Planning & Building
- Bakersfield — Building Division
- Fresno — Building Safety (county)
- Long Beach — Building & Safety
- Los Angeles — City
- Oakland — Vehicular residential facilities / THOW
- Sacramento — Building Division contacts
- San Diego — Movable Tiny Homes
- San Francisco — Building codes
- San Jose — ADUs
Counties with unclear park-model rules
Published guidance for park models / THOWs is thin in these counties. Contact planning or building staff before assuming permanence.
Do you need a permit?
Usually yes. Building permits, ADU / special-use permits, foundation permits, and sometimes Temporary Occupancy (TEM) permits apply depending on the path. Always contact the local building or planning department before delivery.
Example tiny-home communitiesDesignated parks when local rules require community placement
When local rules require a designated park, established communities can be a practical placement option. Verify current availability and residency rules directly with each site.
Delta Bay
922 W Brannan Island Rd, Isleton, CA 95641
Between San Francisco and Sacramento. Amenities often include boat launch/storage, community garden, dog park, fitness center, Wi-Fi, full hookups, laundry, and a pool—useful when local rules require a designated park.
Tiny House Block
9849 Sunrise Hwy, Mt Laguna, CA 91948
Mountain setting with Wi-Fi, parking, fire pit, picnic area, and nearby hiking.
Paradise Tiny Home Community
17989 Corkill Road, Desert Hot Springs, CA 92241
Coachella Valley community with clubhouse, workout room, pool area, and outdoor fire pits.
Partners & build-out resourcesCurated manufacturer links — not endorsements or permit substitutes
After you understand local rules, manufacturer product lines can help you research solar, sanitation, chassis, and compact appliances. Browse the full partners directory.
Featured resources are curated manufacturer links. doihave.space may earn a commission if you buy through them, at no extra cost to you. These are not official partnerships, endorsements, or legal advice for your parcel.
Solar kits & portable power
JackeryPortable solar generators commonly used for staging power and off-grid subsystems during build-out.
Composting toilets
Nature's HeadComposting toilet systems often researched for staged or remote builds — confirm local sanitation rules before purchase.
Trailer chassis
PJ TrailersUtility and specialty trailers that DIY builders often adapt as THOW chassis starting points.
Tiny-home appliances
Unique AppliancesCompact refrigerators and cooking appliances sized for ADU and tiny-home kitchens.
FAQs
How small can a California tiny home be?
Under the common 2025 CBC path, permanent residences need at least one 120 sq ft habitable room and 70 sq ft for each additional habitable room, plus about 7 ft 6 in ceiling height. Local ordinances (especially for THOWs as ADUs) may set different minimums and maximums—often in the 150–400+ sq ft range.
Can I live full-time in a park model?
In many places yes—if the unit is in a permitted RV / special occupancy park, on an approved foundation, or expressly allowed as a moveable tiny house ADU. Some counties ban THOWs as permanent residences. Always verify the occupancy classification before purchase.
What certifications matter?
Park models / THOWs commonly need ANSI A119.5 (and sometimes RVIA labeling). Site-built ADUs follow California Residential / Building Code and local ADU ordinances instead.
Where are lower-cost placement options?
Inland and more rural counties (for example Fresno, Kern, San Bernardino) can be relatively more workable when land, utilities, and fees align—and when local bulletins explicitly welcome park models. Tiny-home communities can also reduce land acquisition friction where park residency is required.
How does this relate to ADU / SB 9 checks?
State ADU law (Gov. Code Chapter 13, §§ 66310–66342) and SB 9 (§§ 65852.21 and 66411.7) create residential pathways that many cities implement locally. A parcel may be ADU-eligible while still restricting wheeled units unless a THOW ordinance exists. Use the doihave.space checker for SF pilot zoning overlays, then read this guide for statewide tiny-home context.