Siskiyou County Zoning, Planning & Building Codes

Last reviewed: July 6, 2026

Overview

Siskiyou County regulates land use in the unincorporated areas through its County Code, primarily Title 10 — Planning and Zoning and the zoning chapters within it. The zoning framework establishes districts, permitted and conditional uses, and countywide dimensional and improvement standards; it also layers hazard and compatibility overlays that can add or supersede base-zone rules. Subdivision activity is governed under the County’s Subdivision Law, and some development paths (like Planned Development) include tailored procedures and standards. This page orients you to where the rules live, what the district families are, and the baseline standards that typically drive entitlements and permits in unincorporated Siskiyou County.

Siskiyou County uses a “permissive” zoning system: if a use is not listed as permitted in a district, it isn’t allowed unless approved through a discretionary process. See § 10-6.303 for the interpretation rule and how the County uses SIC categories to classify uses.

How Siskiyou County’s code is organized

• The zoning rules are in Title 10, Chapter 6 (Zoning). Start with Article 2 (Zoning Plan) for what zoning does countywide and where districts are named, then drill into later articles for procedures and standards.
• Countywide dimensional controls (lot size, setbacks, height, coverage) are centralized in Article 55 and its table, with cross-referenced footnotes that modify standards in specific circumstances.
• Operational and site-development criteria are grouped in Article 56 (Improvement Standards) (e.g., glare, drainage, streets, and landscaping).
• Discretionary approvals live in:
  • Article 12 (Use Permits) — submittal, approval, conditions, appeals.
  • Article 13 (Variances) — criteria and processing.
  • Article 14 (Expiration, Revocation, Appeals) — timelines, revocation findings, and appeal routes.
• Overlay/combining districts appear later in Chapter 6 (e.g., Fault-Rupture Zone Overlay in Article 57; Floodplain Combining standards in Article 54). An additional countywide overlay — the Airport Environs (AE) Combining District — is codified separately as Chapter 1 of Title 10 and is expressly in addition to underlying zone rules.
• Lot splits and mapping are in Title 10, Chapter 4 (Subdivision Law of Siskiyou County) — subdivisions must conform to the General Plan and zoning, and improvements follow the County Land Development Manual.

For quick cross-references on setbacks, parking, and similar topics as you navigate, see the curated pages on Siskiyou County Development Standards, Siskiyou County Parking, and Siskiyou County Design Review.

Zoning district families

The code lists these district families for unincorporated areas in § 10-6.202:

• Residential: Res-1, Res-2, Res-3, Res-4
• Commercial: C-R (Rural Neighborhood), C-U (Neighborhood), C-C (Town Center), C-H (Highway)
• Industrial: M-L (Limited), M-M (Light), M-H (Heavy)
• Rural/Agriculture/Resource: R-R (Rural Residential Agricultural), AG-2 (Non-Prime Agricultural), AG-1 (Prime Agricultural), TPZ (Timberland Production), and O (Open Space)
• Combining/Overlay: B (Combining Districts), F (Floodplain Combining), and FRZ (Fault-Rupture Overlay)
  These districts frame what uses can occur; the ordinance is permissive, so only listed permitted uses are allowed by right in each district per § 10-6.303.

Citywide development standards

Most baseline physical standards are centralized in the dimensional table at § 10-6.5501 (Table 10-6.5501). Highlights:

• Residential examples from the countywide table:

  • R-R: Minimum lot area is 7,200 sq ft with sewer and water, or 1 acre with septic; max dwelling height 35 ft (with an allowance to 40 ft on lots ≥1 acre per footnote 11), accessory height 20 ft, max coverage 40%, min lot width 60 ft, setbacks: 20 ft front, 5 ft side, 20 ft rear. Footnote 3 allows reduced side yards on pre-1957 narrow lots.
  • Res-1: Minimum lot area 7,200 sq ft (sewer/water) or 1 acre (septic); max dwelling height 30 ft, accessory 20 ft, max coverage 40%, min lot width 60 ft, setbacks: 20 ft front, 5 ft side, 20 ft rear.
  • Res-2: Minimum lot area 7,200 sq ft (sewer/water); max dwelling height 35 ft, accessory 20 ft, max coverage 50%, min lot width 60 ft, setbacks: 20 ft front, 5 ft side, 20 ft rear.
  • Res-3: Minimum lot area 7,200 sq ft (sewer/water); max dwelling height 40 ft, accessory 20 ft average, max coverage 75%, min lot width 50 ft, setbacks: 20 ft front, 5 ft side, 10 ft rear; special building-to-building separations apply per footnote 6.

• Additional dimensional and adjacency rules:

  • Where lots in a block are already improved, front setbacks may average down per Table 10-6.5501 footnote 2.
  • When a side or rear lot line abuts an R District, commercial and industrial yards step up (e.g., 10 ft in C-R/C-U, 5 ft in C-C/C-H/M-L/M-M/M-H, with alleys at 10 ft) per footnote 8.
  • Architectural projections can encroach into required yards up to 2.5 ft or 50% of the required setback, whichever is less (§ 10-6.1514).

• Sitewide improvement standards (Article 56) apply across districts:

  • Control of light/glare/heat; compliance with air quality, sewage and water agency requirements; storm drainage/erosion measures; streets for access/circulation/parking/loading per the County Land Development Manual; and landscaping objectives (§§ 10-6.5601–5609). See Siskiyou County Development Standards.

• Use/administration nuances that commonly come up:

  • Home occupations require an administrative use permit and are capped to 25% of home floor area with no employees or outdoor display (§ 10-6.1513).
  • The County’s sign rules live in Article 58; among other items, illumination must shield sources and animated/ flashing signs are prohibited (§§ 10-6.5823–5824). See Siskiyou County Signage.

Specific plans & overlays

• Fault safety: The Fault-Rupture Zone Overlay (FRZ) implements the Alquist-Priolo Act; no structure for human occupancy may cross an active fault or be within 50 ft of it, and a geologic report is required with defined submittal and possible waiver pathway (§§ 10-6.5701–5707).
• Flood hazard: The Floodplain (F) Combining District adds flood-specific permitted/conditional use controls and defers to stricter standards where they conflict; development standards track the companion base district and the County’s flood damage ordinance (§§ 10-6.5402–5404).
• Airport compatibility: The Airport Environs (AE) Combining District overlays airport influence areas; AE criteria are in addition to base-zone rules and the most restrictive standard controls (§§ 10-1.02, 10-1.03, and 10-1.11(e)). See Siskiyou County Overlay Districts.

Note: “Combining Districts (B)” are listed in § 10-6.202; many legacy numbered B-overlays were repealed in 1990 and are retained only as historical notes in the code.

Building permits & review

• Entitlements: Uses listed as permitted proceed ministerially; uses listed as conditional require a Use Permit (application, possible conditions, and appeals as provided in Article 12). Variances follow the criteria in Article 13; expirations, revocations, and appeals are in Article 14 (§§ 10-6.1201–1204; §§ 10-6.1301–1306; §§ 10-6.1401–1405).
• Planned Development (PD): The P-D district enables flexible, multi-phase projects with their own adopted development plan; PDs must meet approval criteria addressing completion timing, compatibility, traffic, and utilities, and include detailed submittals (plot plan, parking/loading plan, circulation, grading, landscaping, elevations) (§§ 10-6.1181–1189).
• Building permits: Construction must comply with the California Building Standards Code and any applicable local building regulations; zoning sections repeatedly cross-reference Building Code compliance (e.g., second units, § 10-6.1515(a)(7)).
• Subdivisions: Under Title 10, Chapter 4, subdivisions must conform to the General Plan and zoning; required public improvements follow the County Land Development Manual (§§ 10-4.101–105).

State housing law in Siskiyou County

• ADUs/JADUs: The local “second unit housing” section (§ 10-6.1515) predates modern state ADU law and contains owner-occupancy and parking provisions (e.g., “one parking space per bedroom”) that state law now limits or supersedes. Under current state law, agencies must allow at least an 800 sq ft ADU with 4 ft side/rear setbacks and cannot require certain parking or owner-occupancy conditions. See California ADU law.
• Density bonus: Siskiyou County implements state density bonus via Article 59 (Density Bonus and Other Developer Incentives), which establishes local procedures and definitions to facilitate affordable housing production (§ 10-6.5901).
• SB 9 and other housing streamlining: Not found in retrieved local code; state provisions apply where eligibility is met. See California housing laws. Not found in retrieved materials.
• Vacation rentals: The County requires a Vacation Rental Activity Permit and limits the use to specific districts, with parcel-size triggers in designated areas (§§ 10-6.6101–6104).

Nonconforming uses and structures

• Nonconforming status is defined and administered in Article 25. Expansions of nonconforming commercial/industrial/multifamily uses over 20% require a Use Permit; ≤20% require an administrative permit. For single-/two-family and ag-related structures, >50% expansions require an administrative permit, while ≤50% do not (§§ 10-6.2501–2502). Damaged nonconforming dwellings can be rebuilt to prior area; commercial/industrial/multifamily over 50% damage must conform to current zoning unless a Use Permit is secured (§ 10-6.2503). See Siskiyou County Nonconforming Uses.

Information Gaps

• Countywide off-street parking ratios by use and any formal Siskiyou County Design Review procedures were not located in the retrieved sections. Verify with the Planning Department. Not found in retrieved materials.
• No local rent stabilization provisions were located in the retrieved zoning materials. Verify with the jurisdiction. Not found in retrieved materials.

Source References

• Title 10, Planning and Zoning (structure; AE overlay) — §§ 10-1.01–10-1.12, 10-1.11(e)
• Zoning plan and districts — §§ 10-6.201–202; permissive-use rule — § 10-6.303; combining uses — § 10-6.304
• Dimensional standards table — § 10-6.5501 (incl. footnotes)
• Improvement standards — §§ 10-6.5601–5609
• Use permits — §§ 10-6.1201–1204; variances — §§ 10-6.1301–1306; expirations/appeals — §§ 10-6.1401–1405
• Fault-Rupture Overlay — §§ 10-6.5701–5707; Floodplain Combining — §§ 10-6.5402–5404
• Signs — Article 58; key limits §§ 10-6.5823–5824
• Density bonus — Article 59; § 10-6.5901
• Nonconforming — Article 25; §§ 10-6.2501–2503
• Subdivision Law — Chapter 4; §§ 10-4.101–105.3; conformance/improvements
• ADUs — local § 10-6.1515; state ADU limits (2025 Handbook summary)