Local zoning · San Luis Obispo County

San Luis Obispo County — Nonconforming Uses

Nonconforming Uses under the San Luis Obispo County local zoning and planning code, with the controlling citations.

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Last reviewed: July 6, 2026

Overview

This page explains how San Luis Obispo County’s inland Land Use Ordinance (Title 22) treats nonconforming uses, structures, parcels, and signs in the unincorporated areas only. Title 22 applies outside the Coastal Zone; Coastal Zone properties follow Title 23, while Title 22 governs the rest of the unincorporated county (§ 22.01.050; Title 22 preface).
Chapter 22.72 sets the rules to “control, improve or terminate” land uses that no longer comply with current standards, while protecting certain continuation rights where uses were lawful when established (§ 22.72.010; § 22.72.030).

The single most important rule: if a nonconforming building/sign/use is destroyed to at least 75% of replacement cost, any replacement must be fully conforming; at less than 75%, it may be restored to its former nonconforming status. Replacement of nonconforming dwellings requires a Minor Use Permit and filing within 6 months of destruction (§ 22.72.080).

What “nonconforming” means (in unincorporated areas governed by Title 22)

  • A use of land that is not allowed today in its location, or was established without the permit now required, or now fails today’s minimum site area or location criteria, can be a nonconforming use of land (§ 22.72.020.A).
  • A nonconforming structure/site fails today’s standards (e.g., height/setbacks, site access, parking, lighting, landscaping/screening, fire safety, undergrounding utilities) or Building Code standards (§ 22.72.020.B).
  • Legal nonconforming uses may continue, but expansions/alterations are tightly limited (§ 22.72.030; §§ 22.72.050–.060).

Core rules and frequent scenarios

  • Continuation right: A lawful nonconforming use can continue; ownership/tenancy may change if the line of business stays substantially the same (§ 22.72.030).
  • Nonconforming use of land — expansions/discontinuance:
    • No enlargement or extension to occupy more land area; new conforming uses on the same site require first bringing the nonconformity into compliance or a CUP with strict findings and a compliance deadline (§ 22.72.050.A).
    • If discontinued ≥6 months (or ≥12 months for a building designed exclusively for that use), any subsequent use must conform (§ 22.72.050.C).
    • A standalone single-family dwelling as a principal use may alter within a cumulative 25% usable floor area increase, with no increase in dwelling unit count, subject to all applicable standards (§ 22.72.050.D).
  • Nonconforming buildings/structures or site development:
    • No increase in floor area/footprint or structural alteration except (1) when alterations are paired with bringing the entire building into full Title 19/California Building Standards Code compliance; (2) minor health/safety fixes; or (3) restoration under § 22.72.080 (§ 22.72.060.A).
    • Additional conforming buildings/uses may be added on the same site by Minor Use Permit, but the existing nonconforming structure must be upgraded to meet Chapter 22.50 Fire Safety, selected Chapter 22.10 environmental standards (air quality, noise, water quality, etc.), and key overlay requirements (Airport Review, Flood Hazard, Geologic Study Areas), and to satisfy Title 19 fire-resistiveness/location rules (§ 22.72.060.B).
  • Destroyed nonconforming structures and signs:
    • At or above 75% destruction: replacement only if fully conforming; below 75%: may restore nonconforming status (§ 22.72.080.A).
    • Nonconforming dwellings: Minor Use Permit, specific findings, and application filing within 6 months of destruction (§ 22.72.080.B.1–4).
  • Nonconforming parking: New or expanded uses on sites with parking deficits must correct parking unless a specific exception applies; substitutions must meet tailored rules, and central business districts have a limited expansion allowance if new parking is provided for the expansion area only (§ 22.72.100).
  • Nonconforming lots: “Legal nonconforming lots” (under‑minimum area or dimensions) may be used for any use allowed in the applicable land use category, subject to minimum site area and lot consolidation standards; groups of such lots may be redivided if they meet Title 21 and minimum area rules (§ 22.72.110; § 22.10.110; § 22.10.100).
  • Nonconforming animal keeping: Numbers cannot increase (except offspring until weaned) and animals that die or are moved >90 days cannot be replaced; nuisance abatement can apply (§ 22.72.090; Ch. 22.74).

Decision-relevant standards at a glance

Topic Key standard Code Reference
Continuation right Lawful nonconforming uses may continue; change in ownership/tenancy OK if business stays substantially unchanged § 22.72.030
Defined nonconformity Covers uses not allowed today, missing today’s permit, or not meeting site/location standards; and structures/sites not meeting zoning or Building Code § 22.72.020
Expansion of nonconforming land use No enlargement; adding a conforming use requires prior correction or CUP with findings/compliance deadline § 22.72.050.A
Discontinuance 6 months generally; 12 months if a building is designed exclusively for that use § 22.72.050.C
Single-family cap Up to 25% total usable floor area increase; no increase in dwelling units § 22.72.050.D
Nonconforming buildings Structural changes allowed only with full building compliance; minor health/safety fixes allowed § 22.72.060.A
Adding conforming uses on same site Requires Minor Use Permit and upgrades (Fire Safety, Chapter 22.10 env. standards, overlays, Title 19/CBSC) § 22.72.060.B
Destruction threshold ≥75% destroyed → must fully conform; <75% → may restore nonconformity § 22.72.080.A
Replacing nonconforming dwellings Minor Use Permit; specific findings; apply within 6 months § 22.72.080.B
Nonconforming parking Substitution/expansion subject to tailored rules; CBD expansion may proceed if new parking is provided for the expansion only § 22.72.100
Legal nonconforming lots May be used consistent with allowed uses; subject to minimum site area and lot consolidation § 22.72.110
Nonconforming signs Tight limits on size, lighting, movement; destroyed signs follow the 75% rule; signs must conform if use is discontinued § 22.72.070

How this interacts with other County processes

  • Applicability: Title 22 applies to inland unincorporated areas (Coastal properties use Title 23) (§ 22.01.050). See the zoning & planning overview and San Luis Obispo County Zoning.
  • Upgrades often require meeting today’s Development Standards (e.g., fire safety, lighting, noise) when adding conforming uses to a site with a nonconforming structure (§ 22.72.060.B).
  • Overlay constraints (e.g., Airport Review, Flood Hazard) can attach additional conditions when reusing nonconforming sites (§ 22.72.060.B). See Overlay Districts.
  • Nonconforming signs are handled alongside the current Signage rules (§ 22.72.070).
  • Parking deficits limit expansions and substitutions; see Parking and § 22.72.100.
  • If full conformity is impracticable, some relief routes may exist through Variances and Exceptions (case-specific; not guaranteed). Not directly addressed in Ch. 22.72; Verify with the jurisdiction. Not found in retrieved materials.

District-by-district notes (Title 22 Land Use Categories, inland unincorporated areas)

These land use categories function like “base districts.” Nonconforming rules in Chapter 22.72 apply across all categories; tables below flag typical allowed uses so you can spot where nonconformities commonly arise. For detailed allowed uses, see the County’s Allowable Use tables (§ 22.06.030 excerpts).

Agriculture (AG)

  • Typical allowed uses: Crop Production and Grazing, certain ag processing, animal keeping (permit levels vary) (§ 22.06.030 excerpts).
  • Nonconforming patterns: legacy dwellings or ag support uses that now exceed intensity or lack today’s permits may be nonconforming; expansions trigger § 22.72.050–.060.
  • Key dimensional standards: Not found in retrieved materials. See Development Standards.

Rural Lands (RL)

  • Typical allowed uses: Resource-based uses (e.g., Crop Production and Grazing, animal keeping) with area-specific limits in some planning areas (Article 9 excerpts).
  • Nonconforming patterns: older residential or commercial activities in resource areas; expansions are constrained by overlays per § 22.72.060.B.
  • Key dimensional standards: Not found in retrieved materials. Verify with the jurisdiction.

Residential Rural (RR)

  • Typical allowed uses: Low-intensity residential with ag-compatible accessory uses (Article 9 excerpts).
  • Nonconforming patterns: historic parcels below minimum site area (§ 22.72.110) or animal densities (see nonconforming animal keeping).
  • Key dimensional standards: Not found in retrieved materials.

Residential Single-Family (RSF)

  • Typical allowed uses: Single-family dwellings; selected community standards apply (§ 22.06.030 excerpts).
  • Nonconforming patterns: setbacks or floor area in older homes; limited to 25% cumulative expansion for nonconforming dwelling as a principal use (§ 22.72.050.D).
  • Key dimensional standards: Not found in retrieved materials.

Residential Multi-Family (RMF)

  • Typical allowed uses: Multifamily housing where mapped (§ 22.06.030 framework). Not found in retrieved materials for details.
  • Nonconforming patterns: buildings exceeding today’s density or parking; expansions trigger § 22.72.060 and § 22.72.100.
  • Key dimensional standards: Not found in retrieved materials.

Commercial Retail (CR)

  • Typical allowed uses: Retail, food service, public assembly (table excerpts).
  • Nonconforming patterns: parking shortfalls limit expansions; sign retrofits controlled by § 22.72.070 and Ch. 22.20.
  • Key dimensional standards: Not found in retrieved materials.

Commercial Service (CS)

  • Typical allowed uses: Business support, warehousing/distribution (A1 in CS), equipment-related services (§ 22.06.030 excerpts).
  • Nonconforming patterns: outside activity areas, parking, and lighting upgrades often required when adding new conforming uses on a nonconforming site (§ 22.72.060.B).
  • Key dimensional standards: Not found in retrieved materials.

Industrial (IND)

  • Typical allowed uses: Manufacturing, distribution, small-scale manufacturing; some uses need CUP (§ 22.06.030 excerpts).
  • Nonconforming patterns: changes of use and expansions are steered by substitution/parking rules (§ 22.72.100) and structural upgrade triggers (§ 22.72.060.A–B).
  • Key dimensional standards: Not found in retrieved materials.

Open Space (OS)

  • Typical allowed uses: Resource/open space functions; strict limits in many areas (§ 22.06.030 excerpts; planning standards).
  • Nonconforming patterns: legacy private facilities; overlays matter (§ 22.72.060.B).
  • Key dimensional standards: Not found in retrieved materials.

Recreation (REC)

  • Typical allowed uses: Parks, outdoor recreation, limited support uses (table/planning area excerpts).
  • Nonconforming patterns: sign/parking corrections when intensifying a use (§ 22.72.070; § 22.72.100).
  • Key dimensional standards: Not found in retrieved materials.

Public Facilities (PF)

  • Typical allowed uses: Civic/institutional facilities; site-specific standards appear in Article 9 (§ 22.06.030 excerpts).
  • Nonconforming patterns: expansions commonly require Minor Use Permit and conformity upgrades (§ 22.72.060.B).
  • Key dimensional standards: Not found in retrieved materials.

Checklist

  • Confirm Title 22 (inland) applies to your unincorporated site; Coastal Zone properties follow Title 23 (§ 22.01.050).
  • Document that the use/structure/lot/sign was lawful when created (e.g., permits, dates, maps) (§§ 22.72.020–.040).
  • If proposing any change: determine whether it is an expansion, substitution, or addition of a conforming use and identify the exact trigger section (§§ 22.72.050–.060; § 22.72.100).
  • For adding conforming uses to a site with a nonconforming structure: prepare upgrades to Fire Safety (Ch. 22.50), environmental standards (Ch. 22.10), and applicable overlays; plan for Title 19/CBSC compliance (§ 22.72.060.B).
  • If damaged/destroyed: obtain a cost assessment; if ≥75% destroyed, plan full conformity; if a dwelling, file a Minor Use Permit within 6 months with required findings (§ 22.72.080).
  • If parking is nonconforming: calculate required spaces for the existing and proposed activity and apply § 22.72.100 rules; note central business district exception (§ 22.72.100).
  • For legal nonconforming lots: verify status and check § 22.10.110 (Minimum Site Area) and § 22.10.100 (Lot Consolidation) alongside § 22.72.110.
  • For nonconforming animal keeping: ensure no increase in numbers; plan for nuisance controls (§ 22.72.090; Ch. 22.74).

Risks & Ambiguities

Issue Why it matters What to verify
Was the use/structure lawful at inception? Continuation rights hinge on lawful establishment Permit history and dates; maps; § 22.72.020–.030
“Substantial” destruction cost at 75% Determines if restoration must fully conform Replacement cost method; County determination; § 22.72.080.A
6- vs 12‑month discontinuance clock Loss of nonconforming status if you miss the window Whether the building was “designed exclusively” for the use; § 22.72.050.C
Adding conforming uses to a nonconforming site Triggers upgrades to fire, environmental, and overlay standards Scope of required upgrades under § 22.72.060.B; potential variances by case
Parking deficits Can block expansions or substitutions Apply § 22.72.100 math; CBD exception; Parking
Nonconforming signs Tight limits on movement/lighting/size § 22.72.070 and current Signage rules
Animal keeping that exceeds today’s standards Replacement or increase may be barred; nuisance risk § 22.72.090; enforcement under Ch. 22.74
Coastal vs inland code Wrong code = wrong standards Location vs. § 22.01.050 (Title 22 vs Title 23)

Plain-English Summary

If your property in the unincorporated inland county has something “grandfathered,” you can usually keep using it as-is, but expansions are restricted. If it’s mostly destroyed (about three-quarters or more), rebuilding must meet all current rules—while smaller damage can usually be repaired back to the old status. Adding new conforming uses on a site with a nonconforming building often forces upgrades to today’s fire, environmental, and overlay standards.

Source References

  • Title 22 Land Use Ordinance, applicability to unincorporated inland areas and not Coastal Zone (§ 22.01.050)
  • Chapter 22.72 Purpose/Definitions/Continuation/Issued Permits (§§ 22.72.010–.040)
  • Nonconforming Uses of Land (§ 22.72.050) — expansion limits, discontinuance clocks, 25% SFD cap, permit cleanup path
  • Nonconforming Buildings/Structures/Site Development (§ 22.72.060) — alteration limits; adding conforming uses with upgrades
  • Nonconforming Signs (§ 22.72.070) — limits and tie to destruction rules
  • Destroyed Nonconforming Structures and Signs (§ 22.72.080) — 75% threshold; dwelling replacement MUP; 6-month filing
  • Nonconforming Keeping of Animals (§ 22.72.090) — no increases; replacement bar; nuisance abatement path
  • Nonconforming Parking (§ 22.72.100) — substitution and expansion framework; CBD exception
  • Nonconforming Lots of Record (§ 22.72.110) — use/redivision rules; minimum site area/lot consolidation cross-references
  • Allowable land uses by category (excerpts of § 22.06.030 tables) — to identify typical category uses

Sources

Retrieved passages

  • San Luis Obispo County Zoning Code (Section 22.72.050) High relevance
  • San Luis Obispo County Zoning Code (Chapter 22.18) High relevance
  • San Luis Obispo County Zoning Code (§ 66314) Medium relevance
  • San Luis Obispo County Zoning Code (§ 66333) Medium relevance
  • San Luis Obispo County Zoning Code (Article 9) Medium relevance
  • San Luis Obispo County Zoning Code (Section 22.06.030) Medium relevance
  • San Luis Obispo County Zoning Code (Section 22.06.060c) Medium relevance
  • San Luis Obispo County Zoning Code (Section 22.30.060.) Medium relevance
  • San Luis Obispo County Zoning Code (Title or) High relevance
  • San Luis Obispo County Zoning Code (Title for) High relevance
  • San Luis Obispo County Zoning Code (Section shall) Medium relevance
  • San Luis Obispo County Zoning Code (Section 22.06.030) Medium relevance
  • San Luis Obispo County Zoning Code (Title unless) Medium relevance
  • CBC § 23.05.042 (Title 19) Medium relevance
  • San Luis Obispo County Zoning Code (Title relating) High relevance
  • San Luis Obispo County Zoning Code (Chapter are) High relevance
  • San Luis Obispo County Zoning Code (Section 22.72.020.A) High relevance
  • San Luis Obispo County Zoning Code (Title is) High relevance

Cited sections

Frequently asked questions

Can I expand a nonconforming business in unincorporated San Luis Obispo County?

Often no. A nonconforming land use generally cannot expand to occupy more area. You may add a new conforming use only if you first correct the nonconformity or obtain a Conditional Use Permit with findings and a deadline to cure, and your parking must comply (§ 22.72.050.A; § 22.72.100).

How long can a nonconforming use sit idle before I lose it?

If a nonconforming use of land stops for 6 months (or for 12 months where the building is designed exclusively for that use), the right to continue ends and any new use must conform (§ 22.72.050.C). Keep records of activity to avoid unintended discontinuance.

My older house doesn’t meet today’s setbacks. Can I remodel?

Yes, within limits. If your dwelling is the principal use on the site, you can alter it but total usable floor area increases are capped at 25%, and you can’t add units. Bigger structural changes may require bringing the entire building up to today’s codes (§ 22.72.050.D; § 22.72.060.A).

What happens if a nonconforming structure is mostly destroyed by fire?

At or above 75% of replacement cost, rebuilding must fully conform to current rules; below 75%, you may restore the nonconformity. Replacing a nonconforming dwelling needs a Minor Use Permit, specific findings, and filing within 6 months (§ 22.72.080).

Can I add a new conforming use on a site with a nonconforming building?

Possibly, with a Minor Use Permit. The County will require upgrades (fire safety, environmental standards, overlays) and Title 19/CBSC compliance for the existing structure as conditions of approval (§ 22.72.060.B).

What if my parcel is smaller than today’s minimum lot size?

A legal nonconforming lot can still be used for allowed uses within its land use category, subject to minimum site area and lot consolidation rules; redivision is possible if Title 21 and minimum area are met (§ 22.72.110).

Do nonconforming parking areas block business changes?

They can. Substituting or expanding uses on a site with nonconforming parking usually requires correcting parking. In central business districts, limited expansions may proceed if parking for the expansion area is added per current standards (§ 22.72.100).

Are nonconforming signs allowed to be moved or brightened?

Generally no. Nonconforming signs can’t be enlarged, intensified, or relocated except under strict conditions; if the associated use is discontinued, on-premise signs must be brought into conformance. Destroyed nonconforming signs follow the 75% rule (§ 22.72.070; § 22.72.080).

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