Shasta County — Nonconforming Uses

Last reviewed: July 3, 2026

Overview

In unincorporated areas of Shasta County, nonconforming buildings, uses, mobilehomes and lots are governed by Chapter 17.90 of the County Zoning Code. The chapter defines what counts as a nonconforming use, limits repairs, enlargement, relocation and reconstruction, sets abandonment rules, and contains special rules for off‑street parking and certain industries (for example, junk yards). For development triggers you should also check local development standards, requirements for parking, and whether a design review or a variance and exceptions is required. Key rules sit in § 17.90.010–060.

What the Shasta County code actually requires (core rules)

• Definition / intent — A “nonconforming” building, structure, mobilehome or use is one that was lawful when established but does not conform to later zoning regulations; the purpose of Chapter 17.90 is to control and phase out incompatibilities while allowing reasonable continuation. § 17.90.010 A.

• Use permits — If a particular structure or use is one for which a use permit is required under the Title, it is treated as nonconforming and may not be enlarged, altered or extended to occupy a greater area unless a use permit is obtained. § 17.90.010 B.

• Maintenance & ordinary repairs — Ordinary maintenance and repairs are allowed to nonconforming structures provided no structural alterations are made and the work does not exceed 25% of the appraised value in any one calendar year. Other repairs require a use permit. § 17.90.020 C.

• Enlargements & relocation — A nonconforming structure may not be added to or enlarged unless the entire resulting structure and use are made conforming to the district regulations; moving a nonconforming structure is allowed only if, after the move, it conforms. § 17.90.020 D–E.

• Reconstruction after damage — A nonconforming structure damaged up to 75% of its appraised value may be restored to its prior nonconforming use if restoration begins within one year and is diligently prosecuted; damage exceeding 75% requires full conformance to current regulations. § 17.90.020 F.

• Historic structures — Repairs, alterations or additions necessary to preserve a designated historic nonconforming structure may be authorized by the Director of Resource Management and the building official, subject to conditions. § 17.90.020 G.

• Change or expansion of nonconforming uses inside structures — A nonconforming use may be changed to a conforming use; changing to another nonconforming use of the same or more restricted nature is allowed only with a use permit; expansion of a nonconforming portion to other portions of a building is prohibited. § 17.90.030 A–C.

• Abandonment — If a nonconforming use is discontinued for more than six months, it may not be reestablished unless the building/land is brought into conformance. § 17.90.030 D.

• Nonconforming land uses — Nonconforming uses of land may continue but must not expand onto same or adjoining land; the use must not be changed except to a conforming use and may not be reestablished if discontinued over six months. § 17.90.040 A.

• Junk/wrecking yards — Special amortization: nonconforming junk/wrecking yards in R‑1, R‑2, R‑3, R‑R, R‑L, C‑1, C‑2 and C‑M districts must discontinue within one year after the ordinance made them nonconforming; in other districts they get two years (or may convert to screened yards subject to rules). § 17.90.040 B.

• Off‑street parking — Where existing off‑street parking does not meet current rules, a structure cannot be altered or enlarged in ways that create additional dwelling units, seating capacity, floor area or guest rooms until the parking requirements are met. See also the county parking rules. § 17.90.050.

• Local emergency rebuild rules — Alternative rules for replacement, repair and reconstruction of nonconforming structures after a declared local emergency are in Shasta County Code § 2.72.100 and § 17.90.060. § 17.90.060.

• Airport overlay — Airport hazard zoning contains its own nonconforming provisions and requires markers/lighting for certain nonconforming structures; see § 17.82.060 and note that airport article provisions are incorporated for nonconforming situations. § 17.82.060; § 17.82.130.

District-by-district breakdown (what matters for nonconforming status)

Below are the Shasta County districts present in the retrieved materials. Each subsection summarizes the district purpose, typical permitted uses where supplied in the code excerpts, key dimensional standards when available, and where the district is applied (notes). If a specific dimensional standard or permitted use was not found in the retrieved materials, that item is marked "Not found in retrieved materials." Verify parcel‑level applicability with the county.

Mixed Use (MU)

• Purpose: Provide a mix of residential, commercial and light industrial uses that will not cause adverse odors/noise/visual impacts. § 17.54.010.
• Typical permitted uses: A variety of agricultural uses (with minimum lot requirements), small commercial storefronts, residential uses. § 17.54.020.
• Key dimensional standards: The chapter contains permitted uses and uses requiring a zoning permit (for example, a one‑ or two‑family residence as accessory subject to lot size rules). Full setback, height and lot area tables not found in the retrieved excerpt — Not found in retrieved materials; check development standards.
• Where it applies: Areas designated “Mixed Use” on the County zoning map. Verify parcel zoning with the County. Verify with the jurisdiction.

Natural Resource/Agricultural – Special (NRA‑S)

• Purpose: Protect estuaries/forest/shoreline and maintain low‑density residential/agriculture where specified. § 17.18.040 excerpt.
• Typical permitted uses: Single‑family residences, supportive and transitional housing, one Accessory Dwelling Unit if primary dwelling exists, small family day care, residential care (6 or fewer). § 17.18.040 A.
• Key dimensional standards: Minimum building site ½ acre (with grandfathering provisions for older lots); heights: main buildings 35 ft, accessory 20 ft; yards: front 20 ft, side 5 ft / 12 ft (special rules for pre‑1978 lots), rear 10 ft. § 17.18.040 B–C.
• Where it applies: NRA‑S mapped areas (verify with County map). Nonconforming structures in this district are subject to Chapter 17.90 reconstruction/repair rules. Verify with the jurisdiction.

Exclusive Agricultural (EA), Limited Agriculture (A‑1) and Unclassified (U)

• Purpose / uses referenced: Certain indoor cultivation/processing of industrial hemp is permitted in EA, A‑1, and U only with a use permit; outdoor cultivation is prohibited. This shows the county uses district names for agricultural zoning. § 17.88.330 E.1.
• Key dimensional standards: Not provided in the retrieved excerpts — Not found in retrieved materials. For nonconforming agriculture/industrial uses see Chapter 17.90 and the hemp-specific exemptions (note: Chapter 17.90 expressly does not apply to hemp declared a nuisance). Verify with the jurisdiction.

Residential and Commercial districts cited in special rules (R‑1, R‑2, R‑3, R‑R, R‑L, C‑1, C‑2, C‑M)

• Purpose / use examples: These district labels are used for typical single‑family, multi‑family, rural residential and commercial/industrial categories (the junk/wrecking yard amortization rules reference them). § 17.90.040 B.
• Key dimensional standards: Specific setbacks, lot sizes and heights for these districts were not contained in the retrieved materials — Not found in retrieved materials. Check the specific district chapters and development standards. Verify with the jurisdiction.

Airport Hazard / Overlay zones

• Purpose: Protect airport operations by limiting heights and uses in approach/transition/horizontal/conical zones; the airport article contains nonconforming rules and requires marking/lighting of certain nonconforming structures/trees. § 17.82.010; § 17.82.060; § 17.82.130.
• Typical restrictions: Height limits tied to approach surfaces; nonconforming uses/structures require marking/lighting and are otherwise protected from becoming more hazardous than on the ordinance effective date. § 17.82.060.
• Where it applies: Land inside mapped airport approach/transition/horizontal/conical zones. Check the airport zoning maps available from the County. Verify with the jurisdiction.

Quick decision table: Most decision‑relevant nonconforming standards

Checklist — What an applicant must confirm or submit (unincorporated Shasta County)

• Confirm the parcel is in an unincorporated area and identify the zoning district on the County map. Verify with the jurisdiction.
• Determine whether the existing use/structure was lawful when established and identify the exact regulation that changed (to prove nonconforming status). See § 17.02.395 and § 17.90.010 A.
• If proposing enlargement, change or restoration, check whether a use permit is required; if so, apply per permit rules. § 17.90.010 B and Chapter 17.92 procedures.
• For repairs, obtain an appraisal or assessor value to confirm the 25% annual repair cap and the 75% reconstruction threshold. § 17.90.020 C, F.
• If the use has been discontinued, confirm length of discontinuance (six‑month rule). § 17.90.030 D.
• Ensure off‑street parking meets current standards before creating additional dwelling units or floor area; consult parking. § 17.90.050.
• If parcel lies inside an overlay (airport, historic, etc.), check overlay rules (for example, airport marking/lighting rules under § 17.82.060). Link to overlay districts and to historic preservation for context.
• If you will seek relief, prepare a variance application per Chapter 17.92 and the variance standards in § 17.92.010. See variances and exceptions.
• If building/repair work is proposed, coordinate zoning approval with building permits and applicable California Building Standards Code requirements. Verify with the jurisdiction.

Risks & Ambiguities

Plain‑English summary

If your house, mobilehome, business or lot in unincorporated Shasta County no longer meets current zoning rules but was legal when it was created, Chapter 17.90 lets you keep using it in most cases — but you generally cannot expand it, you can only do limited repairs (subject to a 25% per‑year cap), and if it is mostly destroyed (over 75% of appraised value) you must rebuild to current rules. If the use stops for more than six months, it usually loses its nonconforming protection. § 17.90.010–060.

Source References

• Shasta County Zoning Code — Nonconforming Uses: § 17.90.010–060.
• Shasta County Zoning Code — Nonconforming buildings and repairs: § 17.90.020 C–G.
• Shasta County Zoning Code — Nonconforming uses of buildings: § 17.90.030.
• Shasta County Zoning Code — Nonconforming uses of land and junk yard rules: § 17.90.040.
• Shasta County Zoning Code — Nonconforming off‑street parking: § 17.90.050.
• Shasta County Zoning Code — Emergency replacement rules: § 17.90.060 (also Shasta County Code § 2.72.100).
• Airport hazard / overlay nonconforming: § 17.82.060; § 17.82.130.
• Definitions: § 17.02.395 (nonconforming buildings and uses).
• District examples: Mixed Use (MU) purpose & uses § 17.54.010–020; NRA‑S requirements § 17.18.040; hemp cultivation references to EA, A‑1, U in § 17.88.330.

Retrieved passages

• Shasta County Zoning Code (title shall) High relevance show source text
• Shasta County Zoning Code (Section 25527) High relevance show source text
• Shasta County Zoning Code (§ 5.06.050) High relevance show source text
• Shasta County Zoning Code (chapter or) High relevance show source text
• Shasta County Zoning Code (§ 5.04.090) High relevance show source text
• Shasta County Zoning Code (chapter shall) High relevance show source text
• Shasta County Zoning Code (Section 25519) High relevance show source text
• Shasta County Zoning Code (Chapter 17.90) Medium relevance show source text

Cited sections

• Shasta County Zoning Code — Nonconforming Uses: **§ 17.90.010–060**. (§ 17.90.010)
• Shasta County Zoning Code — Nonconforming buildings and repairs: **§ 17.90.020 C–G**. (§ 17.90.020)
• Shasta County Zoning Code — Nonconforming uses of buildings: **§ 17.90.030**. (§ 17.90.030)
• Shasta County Zoning Code — Nonconforming uses of land and junk yard rules: **§ 17.90.040**. (§ 17.90.040)
• Shasta County Zoning Code — Nonconforming off‑street parking: **§ 17.90.050**. (§ 17.90.050)
• Shasta County Zoning Code — Emergency replacement rules: **§ 17.90.060** (also Shasta County Code **§ 2.72.100**). (§ 17.90.060)
• Airport hazard / overlay nonconforming: **§ 17.82.060; § 17.82.130**. (§ 17.82.060)
• Definitions: **§ 17.02.395** (nonconforming buildings and uses). (§ 17.02.395)
• District examples: **Mixed Use (MU)** purpose & uses **§ 17.54.010–020**; **NRA‑S** requirements **§ 17.18.040**; hemp cultivation references to **EA, A‑1, U** in **§ 17.88.330**. (§ 17.54.010)
• ShastaCounty_ZoningCode.md
• 2025 California ADU handbook.md

• Official Shasta County code library