Building permits, zoning and land rules in Siskiyou County, California

At a glance

Building permit

Required for a new home in unincorporated areas¹

Zoning

Yes; allowed uses and standards depend on the parcel's district²

Septic

County permit and inspection required for installation, repair or alteration⁶⁷

RV living

Camping on private land needs a Planning Division permit; during home construction a camping permit comes with the building permit and the RV leaves at final inspection⁵⁸

Tiny home

Must fit an approved building or vehicle classification and be allowed at the site⁹

Owner-builder

Available, but the county permit and owner-builder form are still required¹⁰

Ag buildings

Permit-free only on agricultural-zoned parcels of 40+ acres, with an exemption permit¹¹¹²

Water well

County review, permit and inspection required⁴

Minimum lot size

Depends on zoning, the General Plan, water and sewage requirements¹³

Road setbacks

Buildings sit 50 feet from a road centerline or 20 feet from the property line, whichever is greater¹⁴

Who to call

Contact details are copied from each office’s official page and were checked against it on October 16, 2026.

Do you need a building permit in Siskiyou County, California?

Yes. New construction, additions, remodeling, and electrical, mechanical, or plumbing work in unincorporated Siskiyou County require county building permits.¹ The county applies its current building codes to construction plans, including the California code edition effective in 2026.¹⁵ Permit fees vary with the project; the county bases construction valuations used to calculate fees on current ICC valuation data or actual construction cost, as applicable.¹⁶ Permitted work must stay accessible and exposed until the building official approves the required inspections.¹⁷

A qualifying agricultural building can skip the building permit only if it sits on agricultural-zoned land of at least 40 acres, outside a special flood hazard area, at least 20 feet from the property line and 23 feet from any dwelling, with an agricultural building exemption permit obtained before work begins.¹¹¹⁸ On parcels of 40 acres or more the building is limited to 12,000 square feet and 35 feet in height.¹⁹ Electrical and plumbing work still need standard permits and inspections.¹¹ Converting an exempt barn to another use or occupancy requires a Siskiyou County building permit and a Certificate of Occupancy that meets state building codes.²⁰

The county's rules apply to unincorporated land. Inside Yreka the city issues building permits and sets zoning, and Fort Jones has its own building-permit rules for manufactured homes;²¹²²²³ Weed sets its own zoning.²⁴ Septic and well permits for those addresses still go through the county Environmental Health Division.²⁵

Who handles Siskiyou County building permits, and how do you reach them?

The Siskiyou County Building Division accepts building permit applications, begins the review, and routes plans to the relevant county departments and partner cities.²⁶ Reach the division at 530-841-2100 or BuildingPermitTech@co.siskiyou.ca.us, or visit 806 South Main Street, Yreka, CA 96097.²⁶

The Siskiyou County Planning Division maintains the county zoning ordinance and processes land divisions, use permits, zone changes, and variances.²⁷ Planning shares the Community Development counter at 806 South Main Street, Yreka, CA 96097, and the published phone number is 530-841-2100.²⁷ Building permits, zoning approval and septic permits are three separate approvals from three divisions, so a building permit does not cover the septic or well permit.²⁶²⁷²⁵ Environmental Health handles septic and well questions at 530-842-8200 or EHPermitTech@co.siskiyou.ca.us.²⁵ For mapped flood hazards, the Floodplain Administrator handles flood-zone and development-permit questions at (530) 842-8265 or scurry@co.siskiyou.ca.us.²⁸

Does Siskiyou County have zoning?

Yes. Siskiyou County administers zoning districts in unincorporated areas, and the uses allowed on a parcel depend on its assigned district.² Ask the Planning Division for the parcel's zoning through a Property Information Inquiry before treating a listing description as an entitlement.²⁹ Accessory dwelling units are allowed in all residential and agricultural zoning districts, but Environmental Health should verify well and septic capacity when a home already occupies the lot.³⁰

There is no single countywide minimum lot size for every parcel: the applicable General Plan and zoning designation control, and Environmental Health water-supply and sewage-disposal requirements can also affect the result.¹³ Along every county road and every federal or state road, buildings must sit 50 feet from the road centerline or 20 feet from the property line facing the road, whichever is greater; exceptions need Planning Commission and Board of Supervisors approval, and a variance is possible for unusual parcels.¹⁴ Other residential setbacks, lot coverage, and a general minimum dwelling size could not be confirmed, so ask Planning for the standards on the parcel and proposed use. California reserves ordinary setback requirements to local jurisdictions rather than imposing one statewide number.³¹

How do septic permits work in Siskiyou County?

Siskiyou County Environmental Health reviews, permits, and inspects individual sewage disposal systems.³ A county permit is required before installing, repairing, or altering an individual system, and the process includes site evaluation, water-supply documentation, application materials, fees, and specialist review.⁶ Contact Environmental Health at 530-842-8200 or EHPermitTech@co.siskiyou.ca.us before committing to a homesite.²⁵

Only 6% of mapped county soils lack severe limitations for a conventional septic drain field, so a favorable site evaluation should be treated as a purchase condition rather than assumed from acreage alone.³² The completed system receives a final Environmental Health inspection before backfilling and before the premises can be occupied.⁷ Onsite disposal is recognized as an alternative to public sewer, but site suitability, groundwater, slope, water supply, and county and state requirements still apply.³³

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

Living in an RV is not a default right on private land in unincorporated Siskiyou County: camping or squatting on private property without a legally established residence is unlawful unless the Planning Division has issued a permit.⁵ If a legally established home was destroyed by a qualifying natural disaster, an administrative permit may allow RV camping for up to 1 year, subject to water, sewage, cleanup and licensing conditions, and the RV must stay transportable within 4 hours.³⁴ While building a home, a camping permit for an RV or trailer can be obtained with the building permit, ideally requested in the initial application, and the RV must be removed at final inspection.⁸ Lake Shastina campgrounds are day-use only, and overnight camping there is prohibited.³⁵

A tiny home in unincorporated Siskiyou County must receive state or local approval before occupancy as a code-compliant home, manufactured or factory-built unit, RV, park trailer, or camping cabin, and local land-use, health and fire rules still apply.⁹ RVs and park trailers are not intended for permanent year-round occupancy unless a local ordinance allows it.⁹ General parcel-level tiny-home occupancy rules could not be confirmed, so take the unit specifications and parcel number to Planning before purchase.

Building a home in Siskiyou County: what are the steps?

1. Ask Planning to confirm the parcel's zoning, allowed residential use, the 50-foot centerline road setback, and any required land-use approvals.¹⁴²²⁷

1. Have Environmental Health evaluate the proposed water and wastewater setup; the county requires its water-and-sewer clearance with Planning applications.³⁶

1. Obtain the septic permit and any well permit before scheduling work that depends on those approvals.⁶⁴

1. Resolve access: a private roadway connecting to a county road needs a Road Division encroachment permit, while a state-highway connection needs a Caltrans permit.³⁷

1. Obtain the flood-zone determination; development in a Special Flood Hazard Area also needs a separate floodplain development permit before the building application.³⁸

1. Submit the building application and plans, and request an RV camping permit in the same application if you will live on site while building; the Building Division routes plans to the reviewing agencies.³⁹⁸²⁶

1. Keep work exposed for required inspections and obtain the final septic inspection before backfilling and occupancy.¹⁷⁷

What should you check before buying land in Siskiyou County?

Start with parcel-specific feasibility, not the asking price. Confirm zoning and allowed use with Planning, because district rules control development and minimum parcel size can also turn on water and sewage requirements.⁴⁰¹³ New short-term vacation-rental use-permit applications are not accepted for unincorporated properties under 2.5 acres, so rental plans belong in the pre-purchase zoning conversation.⁴¹ Order an Environmental Health site evaluation early: only 6% of mapped soils avoid severe conventional drain-field limitations.³² A private well also requires county review, permitting, and inspection.⁴

Check the flood map and county determination before designing; every development in a Special Flood Hazard Area needs a separate floodplain development permit.³⁸ Verify legal and physical access because connections to county roads and state highways follow different encroachment-permit paths.³⁷ If you plan to divide the land, a tentative and final map are required for subdivisions creating 5 or more parcels.⁴² Finally, budget for carrying costs: the county's median property-tax bill is about $1,880 per year, with an effective rate near 0.7%.⁴³⁴⁴

Watch-outs

• Do not assume a large agricultural parcel makes every barn permit-free; the exemption requires at least 40 acres of agricultural-zoned land, setbacks, a size cap, no habitation and a preapproved exemption permit, and a later change of use needs a building permit.¹¹²⁰
• A flood-zone determination comes before the building application, and development in a Special Flood Hazard Area needs a separate floodplain permit.³⁸
• Private-property RV camping is unlawful in unincorporated Siskiyou County without a Planning Division permit, and the construction-period RV permit ends at final inspection.⁵⁸
• Siskiyou County's general certificate-of-occupancy rule and parcel-level tiny-home standards could not be confirmed; ask the Building and Planning divisions before choosing a structure.²⁶²⁷

Sources

1. Applications and Permits | Siskiyou County California, quoted and re-checked
2. Zoning, quoted and re-checked
3. Land Use, quoted and re-checked
4. Water Wells, quoted and re-checked
5. Camping Administrative Permit – Extended Stay, quoted and re-checked
6. Individual Sewage Disposal Systems Site Review and Permit Procedure, quoted and re-checked
7. Individual Sewage Disposal Systems Site Review and Permit Procedure, quoted and re-checked
8. Permit Application Process, quoted and re-checked
9. Information Bulletin 2016-01: Tiny Homes, quoted and re-checked
10. Siskiyou County Building Division Agricultural Exemption Permit Application, quoted and re-checked
11. Agricultural Building Exemption Permit, quoted and re-checked
12. Agricultural Building Exemption Permit, quoted and re-checked
13. Tentative Subdivision Map Application Guide, quoted and re-checked
14. Pine Place Road Setback Exception Request (SP-24-04), Resolution PC 2025-003, quoted and re-checked
15. Current Building Codes, quoted and re-checked
16. Fees, quoted and re-checked
17. Building Inspection Online Request Form, quoted and re-checked
18. Agricultural Building Exemption Permit, quoted and re-checked
19. Agricultural Building Exemption Permit, quoted and re-checked
20. Agricultural Building Exemption Information Letter, quoted and re-checked
21. Yreka: Yreka Code 16.22.050 Permitted uses (R-3) (Siskiyou County), quoted and re-checked
22. Yreka: Yreka Code 16.18.050 Permitted uses (R-1) (Siskiyou County), quoted and re-checked
23. Fort Jones: Sec. 18.20.160. Manufactured homes; building permits (Siskiyou County), quoted and re-checked
24. Weed: Weed Code 18.12.010 - Districts established (Siskiyou County), quoted and re-checked
25. Siskiyou County Environmental Health Division (siskiyoucounty.gov)
26. Siskiyou County Building Division (siskiyoucounty.gov)
27. Siskiyou County Planning Division (siskiyoucounty.gov)
28. Siskiyou County Floodplain Administration (siskiyoucounty.gov)
29. Zoning, quoted and re-checked
30. Where are Accessory Dwelling Units (ADUs) allowed?, quoted and re-checked
31. California Health and Safety Code Section 17922 (California statewide rule), quoted and re-checked
32. Share of soils USDA rates "not limited" for a conventional septic drain field (SSURGO). A strict rating: the median county is about 6% and a tenth of counties are 0%, so a low figure means most lots need a site evaluation or an engineered system, not that septic is impossible. Cite it only with that caveat: Bolthole Index county data
33. Environmental Health Water and Sewer Clearance, quoted and re-checked
34. Camping Administrative Permit – Extended Stay, quoted and re-checked
35. siskiyoucounty.gov, quoted and re-checked
36. Environmental Health Water and Sewer Clearance, quoted and re-checked
37. Permit Application Process, quoted and re-checked
38. Floodplain Management, quoted and re-checked
39. Permit Application Process, quoted and re-checked
40. Zoning, quoted and re-checked
41. Applications and Permits, quoted and re-checked
42. Tentative Subdivision Map Application Guide, quoted and re-checked
43. Median property tax bill: Bolthole Index county data
44. Effective property tax rate: Bolthole Index county data

Written October 16, 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.