Local zoning · Westminster

Westminster — Nonconforming Uses

Q: What happens if a nonconforming commercial use stops operating for a year in Westminster?

If a nonconforming use is abandoned or discontinued for one year , Westminster does not allow it to be reestablished as a nonconforming use; any new use must conform to current code. See § 17.610.010(B) .

Q: If my nonconforming house is partially destroyed by fire, can I rebuild it as it was?

If damage is 50% or less of appraised value the structure may be rebuilt to original configuration or a lesser nonconformity; if damage is >50% , rebuilding typically requires approval (e.g., Conditional Use Permit) and may need to meet current parking and setback standards — § 17.610.025(A) . Verify historic‑structure exceptions.

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

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Last reviewed: July 3, 2026

Overview

Westminster treats nonconforming uses, structures, and parcels under Chapter 17.610 of the Westminster Zoning Code. The Chapter is designed to allow lawful pre-existing uses and buildings to continue, but limits enlargement, requires time limits for abandonment/rebuilding in some circumstances, and provides special rules for seismic and disaster repair — all intended to encourage gradual compliance and neighborhood improvement. See the Chapter purpose at § 17.610.005 for intent.

How Westminster handles nonconforming situations (key rules)

Continuation but no enlargement: A legal nonconforming use may be maintained but may not increase in area, space, or volume except where the code explicitly allows limited expansions (e.g., single‑family expansions) — § 17.610.010(A).
Abandonment / discontinuance: If a nonconforming use is discontinued or abandoned for one year, it may not be reestablished and any new use must conform to current rules — § 17.610.010(B).
Change of use: Converting a nonconforming use to a conforming use ends the nonconforming status; changing to another nonconforming use is allowed only under narrow timing rules — § 17.610.010(C–D).
Permitted historic/use‑permit continuations: Where an Administrative or Conditional Use Permit existed for a use that later becomes disallowed, that use may continue under the original permit terms (including any expiration), but cannot expand beyond prior extent — § 17.610.010(E).
Nonconforming structures: Additions or enlargements are restricted; increases in area are allowed only when they do not increase the nonconformity (for example, a new addition must meet current setbacks, not increase setback noncompliance) — § 17.610.015(A)(1).
Improvements thresholds: For nonresidential and multi‑family structures the City distinguishes major, minor, and incidental improvements and requires meeting the Table 6‑1 checklist for major/minor work (including parking and screening) — see § 17.610.015(A)(2) and Table 6‑1 requirements.
Destruction and reconstruction: Residential developments damaged ≤ 50% of appraised value may be rebuilt to original configuration; if damaged > 50%, rebuilding often requires a Conditional Use Permit or must meet current standards — § 17.610.025(A).
Seismic and safety repairs: Repairs required by law (including seismic retrofit, Title 24 / California Building Standards Code compliance) are allowed and not capped by the 25% ordinary‑repair limit; Building Official authority applies — § 17.610.030(B).
Nonconforming parcels: A parcel that no longer meets area/width/access standards can still be a legal building site if it was created by approved subdivision, variance/lot line adjustment, or partial government acquisition; further subdivision that worsens nonconformity is prohibited — § 17.610.035(A–B).
Front‑yard paved areas & driveways: Front/street‑side yard paving/driveways that are nonconforming must be brought into compliance when certain thresholds (e.g., removal of > 50% of exterior walls or an addition > 10% or 500 sf) are met — § 17.610.036.
Amortization: The Council may adopt amortization schedules to phase out nonconforming uses or structures where allowed — § 17.610.040.
Enforcement and nuisance: Illegal (never‑permitted) uses have no nonconforming rights and are subject to enforcement; nonconforming uses/structures that are public nuisances can be abated under the WMC nuisance rules — §§ 17.610.045–17.610.050.

Note: Westminster’s nonconforming rules are part of Title 17 (Zoning Code). The City’s permit tables, development standards, and review authorities that are used to decide whether a reuse/repair is allowed are in Article 2 and Article 3 (see cross‑references in the nonconforming chapter).

District-by-district breakdown (purpose, typical permitted uses, key standards, where it applies)

When assessing a nonconforming property you must combine the Chapter 17.610 rules with the specific district rules below. The district development standards and permitted uses are in Article 2 (Tables 2‑2, 2‑3, 2‑4, 2‑5, 2‑7, 2‑9); see the specific § citations for each district.

R1 (Single‑Family Residential)

Purpose: R1 preserves single‑family character and low density (≤ 7 du/acre). § 17.210.005(A).
Typical permitted uses: one‑family dwellings, some accessory structures and home‑based businesses as listed in the residential use table (Tables 2‑2/2‑3). See Article 2 for full list. § 17.200.020.
Key dimensional standards: Minimum lot size 6,500 sf (corner) / 6,000 sf (other); Maximum height 2 stories / 35 ft; Front yard measured per Table 2‑3 (see exceptions) — Table 2‑3 / § 17.210.015.
Where it applies: Residential neighborhoods identified on the City Zoning Map; nonconforming single‑family units may be expanded up to 20% cumulative gross floor area under limited Chapter 17.610 allowance (single‑family expansion rule) — § 17.610.010(G).

R2 (Multiple‑Family Residential – 12 du/acre)

Purpose: R2 provides moderate density multifamily housing. § 17.210.005(B).
Typical uses: multifamily dwellings, limited institutional uses (see Table 2‑2). § 17.200.020.
Key standards: Lot size and setbacks per Table 2‑3; maximum lot coverage 40%; parking as required by Chapter 17.320. § 17.210.015.

R3, R4, R5 (Higher‑density Residential)

Purpose: R3, R4, R5 allow progressively higher densities, with standards shown in Table 2‑3 (density, lot coverage, open space, and height rules) — § 17.210.015.
Typical uses: Multifamily, residential group living per Table 2‑2. § 17.200.020.
Key standards: Maximum lot coverage ranges (e.g., 40–60% depending on zone); minimum open space and parking required by Chapter 17.320. § 17.210.015.

MU36 and MU40 (Mixed‑Use)

Purpose: MU36 and MU40 provide higher density mixed‑use development with specific FAR, height, and front setback ranges — § 17.260.015 and Table 2‑9.
Typical uses: Residential over retail/office, public facilities, limited service uses as listed in the MU use table (Table 2‑8). § 17.260.015 and Table 2‑8.
Key standards: Maximum residential density 36 du/ac (MU36) or 40 du/ac (MU40); height up to 75 ft (MU36 mixed‑use) or 95 ft (MU40 mixed‑use); front setbacks minimum 5–7 ft with maximums noted in Table 2‑9. § 17.260.015.

C‑districts (CR, C1, C2) and CM (Commercial / Mixed)

Purpose: Commercial zones CR, C1, C2 and CM regulate retail, service, and center‑scale commercial uses; standards in § 17.220.015 (Table 2‑5) and permitted‑use listing in Table 2‑4.
Typical uses: Retail stores, restaurants, service uses; C2 is the primary general commercial district (wide list in Table 2‑4). § 17.220.015 / Table 2‑4.
Key standards: Building height (varies; e.g., 2 stories / 35 ft typical), front yard and yard dimensions in Table 2‑5, and off‑street parking per Chapter 17.320. § 17.220.015.

CM, M1, M2 (Industrial / Commercial Manufacturing)

Purpose: CM, M1, M2 serve industrial and limited commercial manufacturing with distinct standards in § 17.230.015 (Table 2‑7).
Typical uses: Warehousing, limited manufacturing, and some commercial retail (CM mixes C2/M1 uses under conditions). Table 2‑7 / Table 2‑4.
Key standards: Minimum lot sizes (e.g., 10,000 sf in CM, 7,200 sf in M2), building height typically 2 stories / 35 ft unless otherwise noted — § 17.230.015.

(For all districts: permitted uses are listed in the Tables 2‑2, 2‑4, 2‑6 and the development standards are in Tables 2‑3, 2‑5, 2‑7, and 2‑9; see § 17.200.020 and the district sections cited above.)

Quick reference table — most decision‑relevant nonconforming rules

Issue / Standard	What Westminster requires	Code Reference
Continuation without enlargement	Nonconforming uses may continue but not enlarge in area/space/volume (limited exceptions)	§ 17.610.010(A)
Abandonment period	Use discontinued/abandoned 1 year → cannot be reestablished	§ 17.610.010(B)
Ordinary alterations cap	Structural/ordinary work in any 12‑month period limited to 25% of appraised market value unless otherwise allowed	§ 17.610.010(A)
Single‑family/duplex expansion	Cumulative expansion up to 20% of existing gross floor area allowed (excl. garages/accessory structures)	§ 17.610.010(G)
Repair after catastrophe	Permitted if rebuilt to original envelope and no more units/area added; building permit within 18 months; otherwise must meet current Title 17 standards	§ 17.610.020(A–C)
Nonconforming parcel legal test	Parcel of record is legal if created by approved subdivision, variance/lot line adj., or partial gov acquisition; cannot be further subdivided to worsen nonconformity	§ 17.610.035(A–B)
Front yard paved areas	If > 50% exterior wall removal or additions > 10%/500 sf then front/street‑side paving must conform to § 17.300.020(D)(2)	§ 17.610.036
Amortization authority	City Council may establish amortization regulations to phase out uses/structures	§ 17.610.040

Checklist — what an applicant must verify or provide when proposing work on a nonconforming site

Identify whether the use/structure/parcel was lawfully established prior to the code change (produce records/subdivision/permits) — see § 17.610.005.
Determine whether the proposed work increases the area/space/volume of the nonconforming use (not allowed except by narrow exceptions) — § 17.610.010(A).
For residential additions, confirm single‑family expansion eligibility and 20% cumulative limit if applicable — § 17.610.010(G).
For multi‑family/nonresidential work, classify the project as incidental/minor/major improvement and meet Table 6‑1 requirements (parking, screening, refuse, landscaping) — § 17.610.015(A)(2) and Table 6‑1.
If the building was damaged, confirm percentage of loss (≤ or > 50%) and follow § 17.610.025 rebuild rules; if >50% verify whether rebuilding requires a CUP or full conformance.
Check off‑street parking impacts and comply with parking standards; if parking deficiency exists, meet the specific nonconforming parking provisions in § 17.610.015.
Ensure seismic/Title‑24 changes required by law are included; these are allowed without dollar caps — see § 17.610.030(B) and consult the California Building Standards Code.
If within an overlay or historic district, check overlay rules and Overlay Districts and Historic Preservation requirements; historic findings may allow special rebuild rights for residences § 17.610.025(A)(2)(c).

Risks & Ambiguities

Issue	Why it matters	What to verify
Whether a use was “lawfully established”	Only lawful pre‑existing uses get nonconforming protection; illegal/unpermitted uses have no rights	Obtain building permits, zoning clearances, prior Administrative/Conditional Use Permits and date of establishment; verify with Division records — § 17.610.005 / § 17.610.045.
What counts as “increase” in nonconforming use	Additions that expand area/volume can terminate nonconforming status	Measure proposed floor area and show it does not enlarge the area devoted to the use (see single‑family 20% exception) — § 17.610.010(A, G).
Parking deficiency conversions	Change of use/addition may trigger required new parking and require additional improvements	Confirm current Chapter 17.320 parking requirements and apply § 17.610.015 rules on parking for nonconforming structures.
Damage rebuild threshold (% of appraised value)	Above 50% triggers different rebuild/approval paths (residential vs commercial)	Obtain appraisal or Building Official determination and confirm required CUP or current‑standards compliance — § 17.610.025.
Conflicts with overlay or specific plan rules	Overlay/Specific Plan provisions may supersede or add requirements	Check overlay map and the specific plan/overlay Chapter 17.250 and applicable specific plan documents — verify with the Division.

If a required fact (dates, permits, appraised value) cannot be confirmed in your file set: Verify with the jurisdiction.

Plain‑English summary

Westminster lets lawful older uses and buildings keep operating, but you generally cannot make them bigger or bring them back after a year of abandonment; limited repairs, seismic safety work, and small residential expansions are allowed under stated caps. Always combine Chapter 17.610 rules with the zoning district tables (e.g., R1, C2, MU36) and parking/design standards to determine what is allowed or needs a permit.

Source References

Westminster Zoning Code, Title 17, Chapter 17.610 (Nonconforming Uses, Structures and Parcels): § 17.610.005, § 17.610.010, § 17.610.015, § 17.610.020, § 17.610.025, § 17.610.030, § 17.610.035, § 17.610.036, § 17.610.040, § 17.610.045, § 17.610.050.
Residential zoning districts and standards (Tables 2‑2, 2‑3): § 17.210.005, § 17.210.015.
Commercial zoning districts and standards (Tables 2‑4, 2‑5): § 17.220.015 and Table 2‑4/2‑5.
Mixed‑use districts (MU36, MU40) development standards: § 17.260.015, Table 2‑9 and Table 2‑8 uses.
Industrial districts (CM, M1, M2) standards: § 17.230.015, Table 2‑7.
Parking requirements referenced throughout: Chapter 17.320 (Off‑Street Parking and Loading) — see cross‑references in § 17.610.015 and district tables.
California Building Standards Code (Title 24) referenced by Westminster for building/safety compliance in nonconforming repairs: § 17.610.030(B).

Sources

Retrieved passages

Westminster Zoning Code (§ 17.610.010.) High relevance
Westminster Zoning Code (title of) High relevance
CBC § 000.00 High relevance
CBC § 2 (Title within) High relevance
Westminster Zoning Code (§ 2) High relevance
Westminster Zoning Code (§ 2) High relevance
CFC § 2 (Article 7) High relevance
CBC § 2 (§ 2) Medium relevance
Westminster Zoning Code (§ 66314) Medium relevance
CBC § 66314 (§ 66314) Medium relevance
Westminster Zoning Code (Article 3) Medium relevance
Westminster Zoning Code (§ 66333) Medium relevance
Westminster Zoning Code Medium relevance
Westminster Zoning Code (Article 7) Medium relevance
Westminster Zoning Code (§ 2) Medium relevance
Westminster Zoning Code (Article 3) Medium relevance
Westminster Zoning Code Medium relevance
Westminster Zoning Code Medium relevance
Westminster Zoning Code (Article 7) Medium relevance
Westminster Zoning Code Medium relevance

Cited sections

Official Westminster code library

Frequently asked questions

What happens if a nonconforming commercial use stops operating for a year in Westminster?

If a nonconforming use is abandoned or discontinued for one year, Westminster does not allow it to be reestablished as a nonconforming use; any new use must conform to current code. See § 17.610.010(B).

Can I enlarge a nonconforming building in Westminster?

Generally no — enlarging the area, space, or volume of a nonconforming use is not allowed except where the code provides specific exceptions (for example, limited single‑family expansions). Additions must not increase the nonconformity and must meet current setback rules for the addition itself. See § 17.610.010(A) and § 17.610.015(A)(1).

If my nonconforming house is partially destroyed by fire, can I rebuild it as it was?

If damage is 50% or less of appraised value the structure may be rebuilt to original configuration or a lesser nonconformity; if damage is >50%, rebuilding typically requires approval (e.g., Conditional Use Permit) and may need to meet current parking and setback standards — § 17.610.025(A). Verify historic‑structure exceptions.

Does Westminster allow seismic retrofits on nonconforming buildings even if cost is high?

Yes. Repairs or alterations required by law for seismic retrofitting and Building Code compliance are allowed and not subject to the usual 25% ordinary‑work dollar cap; the work must comply with current building/fire codes, including State law (Title 24) — § 17.610.030(B).

What if my lot no longer meets today’s minimum lot size or frontage?

A parcel that no longer complies may still be a legal building site if it was lawfully created (approved subdivision, variance or lot line adjustment, or made nonconforming by partial government acquisition). However, you cannot further divide or reduce the site in ways that worsen nonconformity — § 17.610.035(A–B).

Are parking nonconformities treated differently for residential vs nonresidential projects?

Yes. For residential additions full compliance with parking standards is sometimes relaxed (subject to limits like bedroom increases and garage dimensions), but for nonresidential structures the change or expansion must either have the same or lower parking requirement or provide the net new spaces required under § 17.610.015(B) and Chapter 17.320.

Does Westminster have amortization (forced removal) for nonconforming uses?

The Zoning Code gives the City Council authority to establish amortization regulations to phase out nonconforming uses/structures; whether an amortization schedule applies depends on a separate Council‑level action — § 17.610.040. Verify whether a specific amortization resolution exists for your property.

If I propose exterior façade work greater than 10% of value on a nonconforming retail building, what extra rules apply?

Major and minor improvements are objectively defined and trigger Table 6‑1 requirements (including parking, screening, refuse, landscaping and other site upgrades). The Director will not approve such work unless the Table 6‑1 conditions are met — § 17.610.015(A)(2).

Will an overlay zone or the Little Saigon/Historic overlays change nonconforming rules?

Overlay zones add additional standards that apply on top of primary district rules; the Overlay Chapter states overlay provisions apply in addition to other Title requirements and prevail in conflicts — check the map and the overlay text (Chapter 17.250) for site‑specific overlay rules. Verify with the Division for overlay maps — § 17.250.010.

Can nonconforming zoning conditions block an ADU permit in Westminster?

State ADU law limits local denial for nonconforming zoning conditions in many cases. Westminster’s nonconforming rules allow repairs and limited expansions, and ADU applications are subject to state ADU law; for ADU‑specific nonconforming treatment consult local ADU rules and State law. (Westminster nonconforming rules reference repairs/expansions and Title 17 cross references; confirm with the City's ADU procedures.) Not found in retrieved materials: a Westminster‑specific ADU + nonconformance procedure beyond the cross‑references. Verify with the jurisdiction and the City ADU page.

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