Local zoning · Dixon

Dixon — Nonconforming Uses

Nonconforming Uses under the Dixon local zoning and planning code, with the controlling citations.

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Last reviewed: July 2, 2026

Overview

This page summarizes how the City of Dixon treats nonconforming uses, structures, and lots under the Dixon Zoning Code (Title 18). It explains who may continue a pre‑existing use, what repairs, changes, or rebuilds are allowed, and the special rules that apply across the City’s zoning districts (residential, commercial, industrial, public, and overlays). The controlling local rules are in Chapter 18.15 of the Dixon Zoning Code (see the § citations below) and the relevant district development tables in Division II of Title 18.

Note: this page stays strictly within Dixon’s Zoning Code. For matters about building-code compliance, electrical/plumbing permits, or tenant/housing law see the separate resources (e.g., the California Building Standards Code and California housing laws).

How this page links to other Dixon topics

(Those links appear where each topic is first discussed below.)

What the Dixon Code says — quick map of the rules

  • Purpose and scope: § 18.15.010–§ 18.15.020; nonconforming status attaches to land and applies to pre‑existing lawful uses, structures, and lots.
  • Continuation rule (no enlargement or substitution unless allowed): § 18.15.030.
  • Nonconforming lots: allowed to be used as building sites subject to compliance — § 18.15.040.
  • Maintenance, repairs, and limits on additions: § 18.15.050.
  • Repair/rebuild after damage — 50% value threshold and different rules for residential vs nonresidential: § 18.15.060.
  • Changes, expansions, and substitution rules: § 18.15.070.
  • Abandonment: six‑month rule; stop/resume prohibited after abandonment: § 18.15.080.

District-by-district breakdown (what these nonconforming rules mean in each zone)

Below are the principal districts used in Dixon and the development-standard references you will use when evaluating whether a lot, structure, or use is nonconforming and what you can do about it. For dimensional details consult the linked development standards tables.

Notes on terminology: a nonconforming use/structure/lot is one that was lawfully established but no longer meets the current Code. That definition and the high‑level continuation rule are in § 18.15.030.

Residential — RL (Residential Low) and RM (Residential Medium)

  • Purpose: neighborhood residential (single‑family, small‑scale multi‑family in RM). See the Residential development standards in Table 18.04.030.
  • Typical permitted uses: RL = single‑family and limited accessory uses; RM = multi‑family up to the district maximum density. (Detailed use lists are in Chapter 18.04 and the Use Classification tables.)
  • Key dimensional standards (examples, bolded where numeric): RL minimum lot size 7,000 sq ft, front setback 20 ft, maximum height 30 ft; RM minimum lot size 8,000 sq ft, front setback 20 ft, maximum height 38 ft (see Table 18.04.030 / § 18.04.030).
  • Where it applies: all mapped residential parcels; consult the zoning map and the Dixon Zoning page for parcel‑level zoning.
  • Nonconforming implications: a dwelling or accessory structure lawfully built before a change to standards may be maintained and repaired but may not be enlarged so as to increase the nonconformity; repair after >50% damage has special limits for nonresidential uses — see § 18.15.050 and § 18.15.060.

Commercial & Mixed‑Use — DMX, CMX, CN, CR, CS

  • Purpose: downtown mixed‑use (DMX/CMX), neighborhood commercial (CN), retail (CR), and service/commercial (CS). See Table 18.05.030 for development standards.
  • Typical permitted uses: range from retail, office, restaurants, and residential above ground floor (district‑specific; see land use tables in Chapter 18.05).
  • Key dimensional standards (examples): minimum lot sizes vary (from 7,000–20,000 sq ft depending on district), front setbacks 0–20 ft depending on district, maximum heights 30–50 ft in various commercial districts; consult Table 18.05.030.
  • Nonconforming implications: a commercial business lawfully in place before zoning changes may continue but cannot be expanded or change to a different nonconforming classification except as allowed by § 18.15.070; signage that is nonconforming follows Chapter 18.18 rules and nonconforming sign maintenance rules under § 18.15.050(C) apply.

Industrial — IL (Light Industrial), IG (General Industrial)

  • Purpose: industrial activities with graduated intensity (see Table 18.06.030).
  • Typical permitted uses: warehousing, light manufacturing, distribution, limited office and service, with conditional uses for heavier processing.
  • Key dimensional standards: minimum lot sizes 20,000–40,000 sq ft, maximum FAR 0.6, setbacks typically 10 ft front/10 ft rear or greater where adjacent to residential (50 ft interior side/adjacent to R districts).
  • Nonconforming implications: nonconforming industrial structures may be repaired and maintained per § 18.15.050, but substantial reconstruction beyond 50% replacement value typically requires compliance with current Code and nonconforming nonresidential uses may be required to cease after major damage (see § 18.15.060).

Public & Semi‑Public — PF, PR

  • Purpose: public facilities and parks; development standards summarized in Table 18.07.030.
  • Typical permitted uses: government buildings, schools, utilities (permit type varies).
  • Nonconforming implications: the Code treats preexisting public uses similarly — continuation allowed if lawfully established, but alterations and repairs follow the same maintenance and repair rules in § 18.15.050 and the repair thresholds in § 18.15.060.

Overlay districts — examples: GW (Groundwater Well overlay), -PD (Planned Development), -SP (Specific Plan)

  • Purpose and special applicability: overlays carry their own standards and may modify how a nonconforming situation is handled in a mapped area; see Chapters 18.08 (GW), 18.09 (-PD), and 18.10 (-SP). The overlay procedure and required findings may affect approvals for repairs or changes.
  • Nonconforming implications: an overlay can create new nonconformities (or cure existing ones) when adopted; Chapter 18.15 applies to nonconforming conditions created by overlay adoption unless the overlay expressly says otherwise. Verify overlay-specific rules with the Community Development Director.

Quick decision‑relevant table

Issue / Standard What it means in practice Code Reference
Lawful pre‑existing status Only uses/structures/lots lawfully established before the Code (or subsequent amendment) can claim nonconforming rights. § 18.15.030
Continue without change You may continue a nonconforming use/structure but not enlarge or increase occupant load. § 18.15.030(B)
Nonconforming lot buildability A recorded small lot may be used as a building site but must meet other Code requirements; cannot be reduced. § 18.15.040
Maintenance & repairs Repairs that do not increase nonconformity allowed; additions allowed only if they do not increase the nonconformity. § 18.15.050(A–B)
Damage threshold ≤50% of replacement value: allowed to rebuild to previous size; >50%: nonresidential nonconforming uses must cease permanently; residential has limited allowances. § 18.15.060
Abandonment period If a nonconforming use is abandoned/vacated for six months, it may not be resumed. § 18.15.080
Change of use May convert to a permitted use (and then cannot re‑establish the nonconforming use). § 18.15.070(B)

Checklist (what an applicant must show / do)

  • Demonstrate the use/structure/lot was lawfully established prior to the Code effective date or map amendment (e.g., prior permits, dated occupancy records). See § 18.15.030.
  • Confirm whether the nonconforming activity has been abandoned or vacated for six months (utilities, business license, lease status are evidence) — § 18.15.080.
  • If proposing repairs or reconstruction after damage, obtain a certified appraisal to determine whether repairs exceed 50% replacement value and follow § 18.15.060 rules.
  • For proposed alterations or additions, show that changes do not enlarge the nonconforming condition or obtain a variance/PD as needed — see § 18.15.050 and the Dixon Variances and Exceptions process.
  • If the lot is nonconforming, provide recorded map or a certificate of compliance per § 18.15.040 and comply with district development standards in Table 18.04.030 / 18.05.030 / 18.06.030 as applicable.
  • Check whether design review or other discretionary approvals are required (see Dixon Design Review).

Risks & Ambiguities

Issue Why it matters What to verify
Was the prior use "lawful"? Nonconforming rights attach only to lawfully established uses — unlawful past activity isn’t protected. Confirm permits/COs/dated occupancy; check § 18.15.030.
Abandonment determination The City treats a six‑month vacancy as abandonment which extinguishes nonconforming rights. Verify business license, utility records, lease; see § 18.15.080.
Damage appraisal disagreement Whether repair cost is ≤ or > 50% controls rebuild options — disputes are common. Obtain certified appraiser report and discuss with Building Official; see § 18.15.060.
Is an addition “increasing the nonconformity”? The Code allows alterations only if they do not increase the discrepancy with current standards. Provide drawings and demonstrate compliance with § 18.15.050(B).
Lot merges under state law Contiguous nonconforming lots held by same owner may involuntarily merge (Gov. Code § 66451.11 referenced in § 18.15.040(C)). Verify parcel history and title; check § 18.15.040 and Government Code as needed.
Overlay or PD changes Overlays or new PD requirements can create new nonconformities or require different approvals. Verify overlay text in Chapters 18.08–18.10 and consult the Director.

Plain‑English summary

If your use, building, or lot in Dixon was legal when it was created but later failed to meet new zoning rules, you usually can keep using and maintaining it — as long as you don't enlarge it, abandon it for six months, or rebuild after major damage in a way the Code forbids. Repair work that doesn’t increase the nonconformance is allowed; major reconstruction or a change in use triggers stricter rules. See Chapter 18.15 for the exact thresholds and conditions.

Information Gaps

  • The Code text in the provided files defines the nonconforming thresholds and district tables, but the municipal zoning map (parcel‑by‑parcel zoning) was not included in the retrieved materials — Verify the parcel’s current zoning on the City’s official zoning map (not found in retrieved materials).
  • Any administrative forms, fees, or submittal checklists for processing evidence of lawful pre‑existing use are not included in the retrieved files — Verify with the Community Development Department (not found in retrieved materials).

Source References

  • Dixon Zoning Code, Chapter 18.15 — Nonconforming Uses, Structures, and Lots, including § 18.15.010 – § 18.15.080 (Dixon Zoning Code extract).
  • Dixon Zoning Code, Table 18.04.030: Development Standards — Residential Districts (RL / RM) (development standards used above).
  • Dixon Zoning Code, Table 18.05.030: Development Standards — Commercial & Mixed‑Use Districts.
  • Dixon Zoning Code, Table 18.06.030: Development Standards — Industrial Districts (IL/IG).
  • Dixon Zoning Code, Table 18.07.030: Development Standards — Public & Semi‑Public.
  • Dixon Zoning Code, definitions for “Nonconforming Lot/Structure/Use” (Chapter 18.35 Definitions).
  • Dixon Zoning overview pages referenced on this site: Dixon zoning & planning overview, Dixon Zoning, and topic pages linked inline above.

Sources

Retrieved passages

  • Dixon Zoning Code (chapter shall) High relevance
  • Dixon Zoning Code (Chapter 18.15Nonconforming) High relevance
  • Dixon Zoning Code High relevance
  • Dixon Zoning Code (Chapter 18.34) High relevance
  • Dixon Zoning Code High relevance
  • Dixon Zoning Code (Section 18.15.060) High relevance
  • Dixon Zoning Code (Section 18.19.150) High relevance
  • Dixon Zoning Code (Section 18.02.030.D) High relevance
  • Dixon Zoning Code (Section 18.19.150) Medium relevance
  • Dixon Zoning Code (§18.19.110) Medium relevance
  • Dixon Zoning Code (§18.19.070) Medium relevance
  • Dixon Zoning Code (§18.02.030.C) Medium relevance
  • Dixon Zoning Code (Section 18.05.020.A) Medium relevance
  • Dixon Zoning Code Medium relevance

Cited sections

Frequently asked questions

What constitutes a lawful pre‑existing (nonconforming) use in Dixon?

A lawful pre‑existing use is one that was legally established before the effective date of this Code or a subsequent amendment and that now does not meet current zoning rules; those rights attach to the land (not the owner) and are described in § 18.15.030. Evidence (permits, certificates of occupancy, dated records) is used to prove the lawful status.

Can I enlarge a nonconforming building in Dixon?

Not generally. The Code allows maintenance and repairs that do not enlarge the structure or increase building footprint or height; additions are allowed only if they do not increase the discrepancy with current standards (i.e., do not increase the nonconformity) and meet other Code requirements — see § 18.15.050(A–B).

If my storefront was damaged by fire, can I rebuild it and keep the nonconforming use?

It depends on the damage appraisal. If repair/reconstruction costs are ≤ 50% of replacement value, you may rebuild the same size and resume the use. If damage is > 50%, nonresidential nonconforming uses generally must permanently cease; residential nonconforming uses have narrower rebuild allowances — see § 18.15.060 for the distinct rules and timing.

I have a small legal lot that’s below current minimum size — can I build?

Yes — a lawful nonconforming lot (recorded on a subdivision map or with a certificate of compliance) may be used as a building site but must meet applicable requirements and cannot be further reduced; see § 18.15.040. Verify whether contiguous lots held by the same owner may be involuntarily merged under § 18.15.040(C) and Government Code § 66451.11.

What happens if I stop operating a nonconforming business?

If a nonconforming use is abandoned or vacated for six months, it may not be resumed or reestablished — the six‑month clock starts on vacancy, lapse of business license, utilities termination, or lease termination as listed in § 18.15.080.

Can I change ownership or tenancy of a nonconforming business?

Yes — changes in ownership, tenancy, or management are allowed provided the incoming operation is of the same use classification as the previous use (Chapter 18.34 defines use classifications). See § 18.15.070(A).

Does Dixon require a nonconforming sign to be immediately removed?

No — nonconforming signs are subject to maintenance rules and the sign chapter; lawfully established nonconforming signs may be maintained under § 18.15.050(C) but they are also governed by Chapter 18.18 (Signs).

If my ADU or accessory structure is nonconforming, will that block approval of a new ADU?

Dixon’s zoning rules apply, but state ADU law limits denial where nonconforming zoning conditions do not threaten health and safety. For local application see § 18.15.050 and consult the City ADU rules; also see the Dixon ADUs page and state law references. Verify with the Director for parcel‑specific guidance. Not all ADU‑specific nuances are spelled out in Chapter 18.15 (verify with the City).

Where do I start to prove a pre‑existing right in Dixon?

Start with building permits, certificates of occupancy, dated business licenses, utility records, and recorded subdivision maps. Submit these to the Community Development Director as part of any zoning clearance or discretionary application; the rules about proof and continuation are summarized in § 18.15.030–§ 18.15.040.

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