National City — Nonconforming Uses

Last reviewed: July 2, 2026

Overview

National City's Land Use Code treats nonconforming uses, structures, and parcels as lawful remnants of prior zoning that may continue but generally may not be expanded. The controlling rules are in Chapter 18.11 (Nonconforming Uses, Structures, and Parcels) of the Land Use Code; key limits are continuance, restricted enlargement, termination on abandonment or violation, and special rules for single‑family homes, religious institutions, and certain plan areas. See the city's zoning framework for context at National City zoning & planning overview and the Land Use Code at National City Zoning. § 18.11.010

Note: the first time this page mentions related operational topics they are linked to the local menu pages for quick cross-reference: see National City Development Standards, National City Parking, National City Design Review, National City Overlay Districts, National City ADUs, and California Building Standards Code.

Core rules (what the code actually says)

• Purpose / general rule: Nonconforming uses lawfully established before the current Land Use Code may continue but the code intends not to encourage expansion. § 18.11.010

• Continuance: A lawful nonconforming use may continue only so long as it is maintained and occupied; it may not be extended to parts of the building or lot not occupied when it became nonconforming. § 18.11.020

• Enlargements and alterations: Enlargement, extension, reconstruction, or structural alteration of a nonconforming building or premises is prohibited except limited exceptions:

  • Ordinary repairs/alterations up to twice the assessed value in any 12‑month period are allowed.
  • Public-utility facilities may be modernized if setbacks are maintained and the site is not enlarged.
  • Single‑family detached dwellings may be reconstructed or remodeled in the same footprint, height, and location (materials may change).
  • Within the Westside Specific Plan a substituted nonconforming use may expand footprint up to 20% with a conditional use permit. § 18.11.030

• Substitution: A nonconforming use may only be converted to a permitted use in the parcel’s zone, with limited exceptions (conditional use permit for conversion to another nonconforming use in the same zone). The Westside Specific Plan and CA zone have special conversion rules (see § 18.11.040 and CA exception). § 18.11.040

• Partial or total destruction: Nonconforming structures damaged by disaster may be restored if restoration results in equal or lesser nonconformity, is started within one year, and for non‑single‑family structures the repair cost does not exceed one‑half replacement cost. § 18.11.050

• Religious institutions: May be reconstructed or enlarged subject to planning commission approval and compliance with other title provisions; expansions must stay on the parcel(s) with the nonconforming use. § 18.11.060

• Single‑family dwellings: Treated leniently—may be continued, reconstructed, altered, or enlarged following zone standards; height and setback nonconformities are exempt from termination rules, and special parking rules apply for certain enlargements. § 18.11.070

• Nonconforming parking: If a use is nonconforming only because parking requirements changed, expansion is allowed but additional parking may be required per Chapter 18.45; rules for how much parking to add depend on the increase in intensity of use. § 18.11.080 and § 18.45.020

• Nonconforming signs: Special termination rules (abandonment after 90 days, damage threshold 35% of replacement cost, termination on change of business/ownership). § 18.11.090 and sign chapter 18.47.140

• Termination / abandonment: A nonconforming use is terminated by (a) change to a disallowed use, (b) increase in area/volume devoted to the nonconforming use, (c) addition of another disallowed use, or (d) discontinuance for 12 consecutive months (or 18 nonconsecutive months in a 24‑month period). The city may also amortize/use affirmative termination after a hearing; amortization does not apply to lawful nonconforming residential uses. § 18.11.100

• Historic & single‑family exemptions: Historic structures certified as historic may be altered without conforming setbacks with city manager approval; single‑family dwellings have explicit exemptions for height, setback, and parking compliance in certain circumstances. § 18.11.110

• Interim uses: The code allows administrative interim use permits to temporarily reuse buildings that lost nonconforming status due to discontinuance, subject to a required timeline and neighborhood notice. § 18.11.120

• Definitions: The Land Use Code defines "nonconforming use" and "nonconforming structure" in the definitions section of the code; the exact numerical § for the definitions as printed in the retrieved material is Not found in retrieved materials (definition language is available in the Land Use Code text).

District-by-district (how nonconforming rules operate in key zones)

Note: the Land Use Code establishes many zones in Table 18.20.020 (examples below). See the full zone list at Table 18.20.020 in the Land Use Code. § 18.20.020

RS-41 (Residential Single-Family)

• Purpose: neighborhood single‑family areas; typical permitted uses are single‑family homes and accessory uses.
• Nonconforming treatment: Single‑family dwellings that become nonconforming may be continued, reconstructed or enlarged following zone standards; exemptions apply for height and setback nonconformities and parking for certain repairs/expansions. § 18.11.070 and § 18.11.110
• Key development standards: follow Residential zone standards in the development standards tables (see National City Development Standards). Table 18.20.020

RM-11 / RM-21 (Medium / High Density Multi‑Unit Residential)

• Purpose: multi‑unit housing; permitted uses include multi‑family residential and accessory community uses.
• Nonconforming treatment: Residential nonconforming rights are protected (no amortization for lawful residential uses). Rebuilding after disaster allowed under limited cost/time rules. § 18.11.070 and § 18.11.050
• Standards: zone‑specific density, setbacks and parking rules apply; increases in dwelling units or floor area may trigger parking requirements per 18.45. § 18.45.020

CA (Commercial Automotive) and other Commercial (CL, CS, CT)

• Purpose: variety of commercial uses; CA has a narrow commercial automotive character.
• Nonconforming treatment: Special rule allowing older commercial retail shopping facilities in CA to continue leasing to typical shopping‑center uses even if those uses are not otherwise permitted in CA. Substitution/conversion rules in § 18.11.040.C apply. § 18.11.040.C
• Practical note: if lease/tenant changes, signage and use may need to conform per sign rules. 18.47 and § 18.11.090

MXC-1 / MXC-2 (Mixed‑Use Corridor Minor / Major)

• Purpose: pedestrian‑oriented corridors with mixed uses and compact building forms; the nonconforming rules still limit expansion of disallowed uses but the zones focus on physical form and frontage. § 18.24.010–.020
• Nonconforming treatment: continuity allowed but expansions are limited by § 18.11.030; substitutions are permitted only per conversion rules. § 18.11.030–.040

MCR-1 / MCR-2 (Mixed Commercial‑Residential)

• Purpose: mixed commercial and residential development; similar nonconforming treatment as other commercial/mixed zones—use continuation permitted but enlargement and conversions controlled by Chapter 18.11. Table 18.20.020 and § 18.11.030

IL / IM / IH (Industrial Zones)

• Purpose: industrial and manufacturing uses.
• Nonconforming treatment: industrial uses that predate the code continue but cannot expand structures or uses that increase nonconformity; termination rules apply where uses present threats to public safety. § 18.11.030 and § 18.11.100

I (Institutional) and OS (Open Space)

• Purpose: public, institutional, open space uses.
• Nonconforming treatment: institutional and open‑space uses that became nonconforming at code adoption may continue and are subject to special standards in their chapters (e.g., Table 18.26.030 for institutional development standards). § 18.26.030

Westside Specific Plan area (overlay/specific plan)

• Purpose: a specific‑plan overlay with its own allowed uses and Appendix A list.
• Nonconforming treatment: the Westside Specific Plan imposes narrower substitution/conversion options; a converted nonconforming use may expand up to 20% of footprint with a conditional use permit under § 18.11.030(4) and § 18.11.040(B). § 18.11.030(4) and § 18.11.040(B)

(For a complete zone list and where each zone applies see Table 18.20.020 in the Land Use Code.) § 18.20.020

Quick reference table — decision‑relevant items

Checklist (what an applicant must provide / satisfy for a nonconforming proposal)

• Proof property/use was lawfully established prior to the controlling code change (deeds, prior permits, dated business licenses) — verify continuance eligibility under § 18.11.020.
• Clear description of proposed work: repairs vs enlargement vs change of use; demonstrate compliance with allowed exceptions (e.g., repairs under value limit) — see § 18.11.030.
• If increasing intensity or floor area, parking analysis and plan (comply with Chapter 18.45). Link to National City Parking. § 18.11.080 and § 18.45.020.
• If converting to another nonconforming use or substituting in Westside Specific Plan, file for a Conditional Use Permit and attach Appendix A justification (Westside rules) — see § 18.11.040(B).
• If restoring after damage: cost estimates, proof of involuntary damage, and timeline to start work within 1 year — see § 18.11.050.
• If the property is historic or you claim a historic exemption, submit certification/documentation showing status and request city manager approval — see § 18.11.110.
• If applying for temporary reuse after lapse, prepare an interim use permit application including redevelopment timeline and neighborhood notice plan — see § 18.11.120.
• Confirm whether design review or site plan review is required for proposed alterations (see National City Design Review and Site Plan Review rules § 18.12.070).
• Verify compliance with the California Building Standards Code for any reconstruction or repair work (link: California Building Standards Code).

For any ambiguity or parcel‑specific question: Verify with the jurisdiction.

Risks & Ambiguities

Plain-English summary

If your National City property or business was legal before the current zoning rules and later became nonconforming, you generally may keep using it but you cannot expand it, change it to another disallowed use, or abandon it for long periods without losing that right; specific exceptions apply to single‑family homes, religious uses, historic buildings, and some areas like the Westside Specific Plan. See Chapter 18.11 for the controlling rules. § 18.11.010–.120

Source References

• National City Land Use Code — Chapter 18.11, NONCONFORMING USES, STRUCTURES, AND PARCELS: § 18.11.010–§ 18.11.120.
• Nonconforming signs: Chapter 18.47, nonconforming sign rules and abandoned uses (including 18.47.140).
• Off‑street parking: Chapter 18.45 (requirements and how parking changes affect nonconforming uses). § 18.45.020.
• Zone classifications and development tables: Table 18.20.020 (zone list) and mixed‑use zone purpose § 18.24.010–.020.
• Definitions (nonconforming use / nonconforming structure): definition text in the Land Use Code (exact definition section number Not found in retrieved materials).

Retrieved passages

• National City Zoning Code (Chapter 18.11) High relevance show source text
• National City Zoning Code (Chapter 1.36) High relevance show source text
• National City Zoning Code (Chapter 1.36) High relevance show source text
• National City Zoning Code (Section 18.11.040) High relevance show source text
• National City Zoning Code (title shall) High relevance show source text
• National City Zoning Code (Section 18.12.060) High relevance show source text
• National City Zoning Code (Section 18.11.030.) High relevance show source text
• California Plumbing Code High relevance show source text
• CPC § 18.11.100 (Section 18.11.100) Medium relevance show source text
• National City Zoning Code (section may) Medium relevance show source text
• National City Zoning Code (section shall) Medium relevance show source text
• National City Zoning Code (title as) Medium relevance show source text
• National City Zoning Code (Title 18) Medium relevance show source text
• National City Zoning Code (section provides) Medium relevance show source text
• National City Zoning Code Medium relevance show source text
• National City Zoning Code (chapter shall) Medium relevance show source text
• National City Zoning Code Medium relevance show source text
• National City Zoning Code (Section 18.30.260.) Medium relevance show source text

Cited sections

• National City Land Use Code — Chapter 18.11, NONCONFORMING USES, STRUCTURES, AND PARCELS: **§ 18.11.010–§ 18.11.120**. (Chapter 18.11)
• Nonconforming signs: **Chapter 18.47**, nonconforming sign rules and abandoned uses (including **18.47.140**). (Chapter 18.47)
• Off‑street parking: **Chapter 18.45** (requirements and how parking changes affect nonconforming uses). **§ 18.45.020**. (Chapter 18.45)
• Zone classifications and development tables: **Table 18.20.020** (zone list) and mixed‑use zone purpose **§ 18.24.010–.020**. (§ 18.24.010)
• Definitions (nonconforming use / nonconforming structure): definition text in the Land Use Code (exact definition section number Not found in retrieved materials). (section number)
• NationalCity_ZoningCode.md

• Official National City code library