Fullerton — Nonconforming Uses

Last reviewed: July 2, 2026

Overview

Fullerton regulates nonconforming properties in Chapter 15.64: Nonconforming Land Uses of the Municipal Code. The chapter defines nonconforming uses, lots, and development standards, limits enlargement or re‑establishment, and sets restoration and termination rules that apply citywide. Key rules (continuation, repair, enlargement limits, damage/restoration thresholds, and termination for abandonment) are in § 15.64.010 through § 15.64.140 .

The rest of this page synthesizes those rules and explains how they interact with common Fullerton zones such as R-1, R-1P, O-P, and O-S; it points to the code sections you must check and notes what the City staff (Director/Planning Commission) decides versus what is automatic.

(First time certain planning topics are mentioned, linked for quick navigation: see Fullerton Zoning and planning overview, the city’s rules for development standards, parking, design review, overlay districts, and local rules for ADUs. Where the Building Code matters the page references the California Building Standards Code.)

How Fullerton defines and treats nonconformity (core rules)

• What counts — A nonconforming use or condition is one that was lawful when established but no longer complies with zoning rules because of code text or map changes; nonconforming development standards means existing physical features (setbacks, height, coverage, parking, etc.) that no longer meet current measurements. See § 15.64.020 .
• Continuation — A nonconforming property may be maintained and used so long as it is not structurally altered in a way that enlarges area, space or volume, except as the code allows. See § 15.64.040 .
• Repairs and maintenance — Ordinary repairs, non‑bearing work and remodeling that does not enlarge are allowed; strengthening or restoration required by law is allowed. See § 15.64.050 .
• Enlargement / extension — Generally prohibited. If the nonconformity is only to development standards (not the use), the Director may allow an increase in area/length up to 10% of the existing structure, provided all other zone regulations are met (§ 15.64.060(A)) . If the nonconformity is due solely to parking, expansion that increases capacity is barred unless additional parking to meet current standards is provided (§ 15.64.060(B)) .
• Damage / reconstruction — A damaged nonconforming structure may be rebuilt to an equal or lesser degree of nonconformity if reconstruction starts within 1 year and completes within 2 years; but if damage exceeds 50% of fair market value immediately prior to damage, the structure must be reconstructed to current standards (with a narrow exception for certain dwelling units) (§ 15.64.120) .
• Termination / abandonment — A nonconforming use ends if it changes to a conforming use, or if it is not in operation for 6 consecutive months (or intermittently for a total of 1 year over any 3‑year span) (§ 15.64.130) .
• Nonconforming lots — Lots legally created before annexation or prior to June 18, 1953 (and certain later lots) that are smaller than current minimums may still be used consistent with their zone despite size deficiency (§ 15.64.090) .
• Fair‑market valuation and appeals — The Director determines the fair market value and damage amount; the Director’s determination can be appealed to the Planning Commission and then to City Council (§ 15.64.120(C)) .
• Historic landmarks — Chapter 15.64 does not apply to city‑designated historic landmarks; different rules apply for historic properties (§ 15.64.140) .

District-by-district breakdown (decision‑relevant summary)

Notes: Fullerton’s zone list and the relative order of restrictiveness are established in § 15.08.020; specific permitted uses and development standards appear in each chapter (e.g., Table 15.17.020(A) for residential uses) . Where a district-specific code excerpt is not found in the retrieved materials, the entry says “Not found in retrieved materials — verify with the jurisdiction.”

R-1 (One‑Family Residential)

• Purpose: Preserve single‑family neighborhoods; most restrictive residential use class in the city (§ 15.08.020) .
• Typical permitted uses: single‑family dwellings, accessory structures, ADUs/JADUs subject to Table 15.17.020(A) and § 15.17.100 (ADU rules) .
• Key dimensional standards (decision‑relevant): lot coverage for R-1 through R-3R is limited to 50%; minimum lot sizes are shown on the zoning map (e.g., R-1-6 = 6,000 sq ft) under § 15.08.050 and site standards references in § 15.17.050 and Appendix A .
• Where it applies: Citywide single‑family neighborhoods as shown on the official zoning map; nonconforming physical conditions (e.g., reduced setback or lot width) are treated as nonconforming development standards under § 15.64.020 and may continue per the continuation/repair rules unless enlarged (§ 15.64.040, § 15.64.050) .
• Special notes: ADU/JADU specific allowances reference nonconforming and unpermitted units may be legalized under the ADU chapter without requiring correction of unrelated nonconforming zoning conditions as a condition of approval (see § 15.17.100 and related subsections) .

R-1P (One‑Family Residential — Preservation)

• Purpose: Same residential base as R-1 but with preservation overlays/limits to protect historic/character areas (§ 15.08.020) .
• Typical permitted uses: As R-1 with preservation restrictions; ADU/JADU allowances are limited similarly but with added historic exclusions in the ADU rules (legalizing provisions exclude historic properties; see § 15.17.100(C)) .
• Key dimensional standards: Uses and standards follow R‑1 but driveway widths and certain design controls can be more restrictive (see access and circulation standards, § 15.17.085(B)) .
• Where it applies: Areas shown as “P” on the zoning map; nonconforming features are still governed by Chapter 15.64 except where historic preservation rules supersede (§ 15.64.140) .

O‑P (Office‑Professional)

• Purpose: Professional and office uses, with limited residential conversions allowed in former single‑family buildings (see § 15.30.030 series) .
• Typical permitted uses: Offices, small medical/dental, limited retail/service uses; a list of permitted conditional uses (car rental, childcare center, fitness, restaurants, parking structures, etc.) appears in § 15.30.030. .
• Key dimensional standards & ADU note: Properties in O‑P that are currently developed with a building originally constructed as a single‑family residence may be eligible for one ADU or JADU under § 15.17.100; otherwise nonconforming structures in this zone follow Chapter 15.64 for continuation and enlargement limits .
• Where it applies: Office corridors and parcels shown as O‑P on the zoning map; consult Table 15.17.020(A) and § 15.30.030 for detailed permitted uses and MSP/CUP categories .

O‑S (Open Space)

• Purpose: Parks, flood control, public open space, and limited accessory uses; special wildlife habitat sub‑zones are stricter (§ 15.27.030 and O‑S‑WH rules) .
• Typical permitted uses: public parks / playgrounds, flood control, public educational facilities, limited noncommercial agriculture; new oil facilities subject to distance conditions in § 15.27.030 .
• Key dimensional standards: Use restrictions are tight; Chapter 15.64 still applies to nonconforming uses created elsewhere that fall within an O‑S boundary due to map changes, but many O‑S areas do not permit new structures. See § 15.64.090 and § 15.64.100 for public acquisition effects on nonconforming lots/uses .
• Where it applies: Parks, open‑space parcels and wildlife subzones as mapped.

C‑3 / Commercial and Other Zones (brief)

• Purpose & uses: Commercial zone permitted uses lists are in § 15.30.030 series (e.g., C‑3, C‑M, G‑C). Nonconforming commercial uses are covered by the same Chapter 15.64 rules for continuation, repairs, enlargement, and termination .
• Key dimensional standards: Lot coverage, parking, loading and setbacks are specified in the commercial zone chapters and Appendix A; nonconforming development standards are explicitly listed in § 15.64.020 (setbacks, height, lot coverage, parking, landscaping, etc.) .

Quick reference table — most decision‑relevant nonconforming standards

Checklist (what an applicant must satisfy when proposing work on a nonconforming property)

• Confirm whether the issue is a nonconforming use (use conflict) or a nonconforming development standard (setbacks, coverage, parking) — see § 15.64.020 .
• If proposing structural work, determine whether the work enlarges area/space/volume; enlargement is generally prohibited unless within 10% and approved by the Director (§ 15.64.060(A)) .
• For any enlargement that increases dwelling units, seating, or guest rooms, prepare to provide additional spaces to meet current parking standards unless exempt under city ADU or other sections (§ 15.64.060(B)) .
• If repairing after damage, document fair market value before damage and estimated repair cost; if damage > 50% of fair market value, expect reconstruction to current standards unless the dwelling exception applies (§ 15.64.120) .
• If the nonconforming issue is an existing ADU/JADU or you plan to legalize one, check § 15.17.100 and the ADU chapter for legalization allowances and interplay with nonconforming zoning conditions .
• If the property is within a preservation or historic overlay, confirm historic exceptions because Chapter 15.64 does not apply to designated landmarks (§ 15.64.140) .
• Be ready to accept Director determinations (e.g., fair market value); prepare for appeals to the Planning Commission and City Council as described in § 15.64.120(C) .

Risks & Ambiguities

Plain‑English summary

If your Fullerton property or building was lawful when built but now conflicts with the zoning map or newer rules, Chapter 15.64 lets you keep it and make ordinary repairs, but it bars enlarging the nonconforming part (with narrow exceptions), limits rebuilding after major damage, and ends the nonconforming right if the use lapses for extended periods — check § 15.64.020–§ 15.64.130 for the exact triggers and timelines .

Source References

• Chapter 15.64: Nonconforming Land Uses, City of Fullerton Municipal Code, § 15.64.010 – § 15.64.140 (intent, definitions, continuation, maintenance, enlargement, restoration, termination, historic exceptions) .
• Residential permitted uses and ADU/JADU rules, Table 15.17.020(A) and § 15.17.100 (ADUs/JADUs: legalization and parking exceptions) .
• Zone classifications and order of restrictiveness, § 15.08.020; minimum lot sizes/zoning map rules § 15.08.050 .
• O‑S zone permitted uses, § 15.27.030 (Open Space rules and wildlife sub‑zones) .
• Commercial & O‑P permitted-uses excerpts, § 15.30.030 series (O‑P uses) .
• Development standards references (lot coverage, density, usable open space) and Appendix A citations (site standards), e.g., lot coverage limit for R‑1–R‑3R § 15.17.050 / Appendix A .
• Fullerton Municipal Code excerpts used in this page are provided from the uploaded Fullerton_ZoningCode.md file (various sections cited above) .

(If you want direct links to any of the specific Fullerton code sections I cited above, tell me which § and I will pull the exact text or provide the staff contact to confirm parcel‑specific application. Verify with the City — some answers (valuation, appeal scheduling, map interpretations) require case‑specific staff determinations.)

Retrieved passages

• Fullerton Zoning Code (title or) High relevance show source text
• Fullerton Zoning Code (§ 15.64.110) High relevance show source text
• Fullerton Zoning Code (§ 15.64.090) High relevance show source text
• Fullerton Zoning Code (title and) High relevance show source text
• Fullerton Zoning Code (§ 15.64.065) High relevance show source text
• Fullerton Zoning Code (§ 15.64.120) High relevance show source text
• CFC § 15.64.010 (CHAPTER 15.64) Medium relevance show source text
• Fullerton Zoning Code (§ 15.27.030) Medium relevance show source text
• CFC § 15.58.095 (§ 15.58.095) Medium relevance show source text
• CBC § 66341 (§ 66341.) Medium relevance show source text
• Fullerton Zoning Code (Chapter 15.04) Medium relevance show source text
• CBC § 66341 (§ 66341.) Medium relevance show source text
• CBC § 17960 (Chapter 5) Medium relevance show source text
• Fullerton Zoning Code (§ 15.20.110) Medium relevance show source text
• Fullerton Zoning Code (§ 15.17.030) Medium relevance show source text
• Fullerton Zoning Code (§ 15.08.020) Medium relevance show source text

Cited sections

• **Chapter 15.64: Nonconforming Land Uses**, City of Fullerton Municipal Code, **§ 15.64.010 – § 15.64.140** (intent, definitions, continuation, maintenance, enlargement, restoration, termination, historic exceptions) . (Chapter 15.64)
• **Residential permitted uses and ADU/JADU rules**, Table **15.17.020(A)** and **§ 15.17.100** (ADUs/JADUs: legalization and parking exceptions) . (§ 15.17.100)
• **Zone classifications** and order of restrictiveness, **§ 15.08.020**; minimum lot sizes/zoning map rules **§ 15.08.050** . (§ 15.08.020)
• **O‑S zone permitted uses**, **§ 15.27.030** (Open Space rules and wildlife sub‑zones) . (§ 15.27.030)
• **Commercial & O‑P permitted-uses excerpts**, **§ 15.30.030** series (O‑P uses) . (§ 15.30.030)
• Development standards references (lot coverage, density, usable open space) and Appendix A citations (site standards), e.g., lot coverage limit for R‑1–R‑3R **§ 15.17.050 / Appendix A** . (§ 15.17.050)
• Fullerton Municipal Code excerpts used in this page are provided from the uploaded Fullerton_ZoningCode.md file (various sections cited above) .
• Fullerton_ZoningCode.md

• Official Fullerton code library