Building permits, zoning and rural land rules across California

At a glance

Residential building permits

0 counties with none; 3 with requirements only in some cases; 55 requiring a building permit¹³²

County zoning

58 counties have zoning; 0 have neither county zoning nor a residential building permit⁴⁸

Septic permits

County offices in 55 counties; district authorities in 3 counties, with state oversight⁹¹⁰

RV residence

47 counties have an answer; 11 remain unconfirmed; local permission matters¹¹⁶

Tiny homes

29 counties have an answer: 12 allow qualifying tiny homes and 17 impose limitations¹²

Owner-builder

Contractor licensing exemption available with conditions; building permits and inspections still apply¹³¹⁴

Water wells

Obtain local well permits before construction, modification or destruction¹⁵

Property tax

Median county effective rate: 0.7%; median county bill: $3,172 annually¹⁶

Who to call

Contact details are copied from each office’s official page and were checked against it on October 10, 2026.

Which California counties don't require a building permit?

California has 0 counties classified as requiring no residential building permit, 3 with requirements only in some cases, and 55 requiring a residential building permit.¹³² These county counts concern unincorporated land; incorporated cities exercise their own building and zoning authority.¹⁷¹⁸

California's 2025 Building Standards Code applies to buildings and structures with permit applications dated January 1, 2026 or later.¹⁹ California's owner-builder exemption concerns contractor licensing, and owner-builders must obtain building permits and pass inspections.¹³¹⁴ Use the California owner-builder guide to explore that exemption, then ask the parcel's building official which building permits the proposed project needs.¹³²⁰

Which California counties have no zoning?

California has 0 counties without county-wide zoning, and all 58 counties have county zoning.²¹⁴ California also has 0 counties classified as having neither a residential building permit nor county-wide zoning.⁸

California county and city legislative bodies can regulate land uses, building location and size, lot coverage, parking and setbacks through zoning ordinances.¹⁸ Building setbacks, side and rear yards, and property-line requirements are generally reserved to local jurisdictions, subject to statutory exceptions.²² Before choosing rural land, ask the county planning office for the parcel's zoning district and the proposed dwelling's applicable land-use and setback requirements; inside city limits, ask the city planning office.¹⁸²²

Who issues septic permits in California?

County offices issue septic permits in 55 California counties, while district authorities serve 3 counties.⁹ Named county agencies include Alameda County Department of Environmental Health and Butte County Environmental Health Division.⁹ The State Water Resources Control Board establishes the statewide onsite wastewater treatment system policy, and local agencies issue septic permits under that framework.⁵

New and replacement systems follow applicable local permitting and design requirements; existing properly functioning systems have a separate policy category.²³ Approved Local Agency Management Programs can tailor siting and design standards locally.⁵ Ask the parcel's local septic agency for its application, site-evaluation requirements and current septic permit fee; use the Water Board's regional jurisdiction page when the responsible office is unclear.²³²⁴

Can you live in an RV or tiny home on your land in California?

California RVs are not intended as permanent dwellings; unless a local ordinance allows otherwise, RV occupancy generally belongs in mobilehome or special occupancy parks.⁶ County-specific RV answers exist for 47 counties: 2 classified as allowed, 17 temporary-only, 23 limited and 5 prohibited; 11 remain unanswered.¹¹ The allowed entries need care: San Luis Obispo County concerns principal residence on a mobilehome space, while Riverside County describes personal RV parking rather than residential occupancy.¹¹ Ask the county planning office about residential occupancy of the proposed parcel before relying on the California RV guide.⁶

Tiny-home answers exist for 29 counties: 12 allow qualifying homes and 17 impose limitations; another 29 remain unanswered.¹² Mendocino County, Nevada County and Trinity County have allowances for movable tiny homes subject to local conditions.¹² California requires an approved housing classification and an approved location for tiny-home occupancy; use the California tiny-home guide to narrow the search.⁷

Where are the best California counties for a bolthole?

Humboldt County leads California's Bolthole Index at 60, followed by Mendocino County, Placer County and Shasta County at 56 each.²⁵ Nevada County, Butte County, Lassen County and Del Norte County complete the leading group; all of these counties require residential building permits, have zoning and use county septic authorities.²⁵

The median county farmland value is $11,471 per acre, and the median county effective property tax rate is 0.7%, with a median county annual tax bill of $3,172.²⁶¹⁶ Inyo County has the lowest listed farmland value at $961 per acre, followed by Sierra County at $2,427.²⁶ Use these county farmland values and tax medians as comparison measures, then request parcel-specific pricing and a tax estimate.

What should you check about California water wells and road access?

California well owners need local well permits before construction, modification or destruction, and water-well construction must be performed by a licensed well-drilling contractor.¹⁵ DWR sets minimum well standards, while local enforcing agencies administer well permits and may adopt stricter standards.²⁷²⁸

Parts of 45 California counties fall inside a special groundwater management regime, including actively managed, declining and adjudicated basins; a county-level designation does not identify the regime for every parcel.²⁹ Ask the local environmental health agency or water district which well ordinance applies and whether the parcel falls within a groundwater management area.¹⁵²⁹ For proposed access work within a state highway right of way, California requires a Caltrans encroachment permit from the appropriate District Encroachment Permits Office.³⁰

Watch-outs

• California county counts describe unincorporated land; ask the city building and planning offices about a parcel inside incorporated city limits.¹⁷¹⁸
• California owner-builders remain responsible for building permits, code compliance and building inspections.¹⁴
• We could not confirm a statewide allowance for composting toilets or other off-grid sanitation; ask the local septic agency and building official about the proposed system.⁵²⁰
• California tiny homes require both an approved structure classification and an approved location, even where a county allows qualifying tiny homes.⁷

Sources

1. Bolthole Index county rulebook, 58 California counties, as of October 10, 2026: California counties that do not require a residential building permit in unincorporated areas
2. Bolthole Index county rulebook, 58 California counties, as of October 10, 2026: California counties that require a residential building permit in unincorporated areas
3. Bolthole Index county rulebook, 58 California counties, as of October 10, 2026: California counties that require a residential building permit only in some cases (for example floodplain or certain structures)
4. Bolthole Index county rulebook, 58 California counties, as of October 10, 2026: California counties with county zoning
5. California: Onsite Waste Water Treatment Systems, quoted and re-checked
6. California: hcd.ca.gov, quoted and re-checked
7. California: Information Bulletin 2016-01: Tiny Homes, quoted and re-checked
8. Bolthole Index county rulebook, 58 California counties, as of October 10, 2026: California counties with neither a residential building permit nor county-wide zoning
9. Bolthole Index county rulebook, 58 California counties, as of October 10, 2026: Who issues septic permits across California's counties: a state agency, a multi-county health district, or the county
10. California: Water Quality Control Policy for Siting, Design, Operation and Maintenance of Onsite Wastewater Treatment Systems (OWTS Policy), quoted and re-checked
11. Bolthole Index county rulebook, 58 California counties, as of October 10, 2026: California counties' answers on living in an RV on your own land
12. Bolthole Index county rulebook, 58 California counties, as of October 10, 2026: California counties' answers on living in a tiny home on your own land
13. California: California Business and Professions Code Section 7044, quoted and re-checked
14. California: Owner-Builder Responsibilities, quoted and re-checked
15. California: Well Standards, quoted and re-checked
16. Bolthole Index county rulebook, 58 California counties, as of October 10, 2026: Median of California's county effective property tax rates and median county property tax bills
17. California: Information Bulletin 2021-02: 2019 California Building Standards Code Supplement, quoted and re-checked
18. California: California Government Code Section 65850, quoted and re-checked
19. California: Approved Building Standards, quoted and re-checked
20. California: Do I need a building permit for my project?, quoted and re-checked
21. Bolthole Index county rulebook, 58 California counties, as of October 10, 2026: California counties with no county-wide zoning
22. California: California Health and Safety Code Section 17922, quoted and re-checked
23. California: Onsite Waste Water Treatment Systems, quoted and re-checked
24. State Water Resources Control Board — OWTS Program (waterboards.ca.gov)
25. Bolthole Index county rulebook, 58 California counties, as of October 10, 2026: The 8 highest-scoring California counties on the Bolthole Index (off-grid and homestead land score out of 100), with each one's building-permit, zoning and septic answers
26. Bolthole Index county rulebook, 58 California counties, as of October 10, 2026: Median farmland value per acre across California's counties (USDA census, the middle county's value; USD/acre), with the five least expensive counties
27. California: Well Standards, quoted and re-checked
28. California Department of Water Resources — Well Standards Program (water.ca.gov)
29. California water rights and groundwater management: National Agricultural Law Center and Bolthole Index groundwater review
30. California: Encroachment Permits | Caltrans, quoted and re-checked

Written October 10, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.