Merced County — Nonconforming Uses

Last reviewed: July 6, 2026

Overview

This page explains how Merced County’s Title 18 (Zoning) treats nonconforming uses, structures, signs, and parcels in the unincorporated areas. The rules live in Article V (Nonconformities) and apply regardless of base zoning district; they control how long a nonconformity may continue, when it must be brought into compliance, and what limited changes are allowed. See the County’s broader zoning and development standards pages for the baseline rules that nonconformities deviate from.

Plain-English rule of thumb: if a use or structure was legal when established in the unincorporated areas, it can usually continue as-is, but Merced County places tight limits on expansion, replacement after major damage, and any gap in operation longer than 180 days.

What “nonconforming” means in Merced County

• The code defines protected nonconformities and makes clear that illegal nonconformities have no protections. Key terms include legal nonconforming use, structure, parcel, and sign; “cessation or discontinuance” is defined as abandonment regardless of owner intent.
• The property owner bears the burden to prove legal nonconforming status to the Planning Director, with notice/hearing and an appeal path to Chapter 18.144.

Continuation, change, and discontinuance of nonconforming uses

• Continuation is allowed if the use and its intensity do not change; a change in management or ownership alone does not void status. Any additional development on the site must meet current zoning rules.
• Converting a nonconforming use to a conforming one extinguishes the right to revert to nonconforming.
• A nonconforming use may change to another nonconforming use only if the new use is of equal or more restrictive classification as determined by the Director; it cannot later change back to a less restrictive class.
• If a nonconforming use ceases for 180 consecutive days, its status terminates and future use must fully comply. This 180-day rule is cross-referenced in both the general and uses chapters, which also list how cessation is judged (e.g., no receipts or utility bills).

General nonconforming provisions (apply countywide in unincorporated areas)

• Customary maintenance and repair are allowed, but structural alterations to supporting members are generally barred unless for health/safety. Limited improvements are allowed, including:
  • One accessory structure to a conventional single-family dwelling (not an ADU);
  • Agricultural sheds/hay barns, etc., where there is no increase in animals, wastewater, or employees;
  • Expansion of certain emergency-service communications facilities by CUP, up to 100% additional floor area, with specific findings.
• Nonconformities terminate if involuntarily destroyed or deteriorated ≥50% of appraised value; repairs are capped cumulatively at 50% from the initial nonconformity date. The County relies on a state-licensed appraiser and Building Official confirmations.

Nonconforming structures: how they interact with uses

• Legal nonconforming structures may continue and receive ordinary maintenance. Nonstructural alterations may be approved for safety, subject to a 50% value cap. Additions are allowed only if the additions meet current standards; any new structures or additions on a parcel with a nonconforming structure must comply.
• If a nonconforming structure is involuntarily damaged ≥50%, it can only be restored if brought into full compliance; special “Residential Exceptions” allow like-for-like footprint and height reconstruction of damaged nonconforming single-family and multi-family dwellings (with continued unit count in multifamily), subject to Building/Fire Code and certain State Government Code provisions.

Note: Residential exceptions reference construction codes; for the construction standard side, see the California Building Standards Code.

Nonconforming parcels (lots)

• A single legal nonconforming parcel may be a buildable site if it meets one of four County criteria (e.g., recorded subdivision, legally created by deed before the standard, variance/lot line adjustment, or partial government acquisition with size/yard thresholds).
• Subdivisions or lot line adjustments cannot increase the degree of nonconformity on the parcel or any nonconforming use. Contiguous nonconforming parcels under common ownership may be involuntarily merged per Government Code § 66451.11.

Parking, landscaping, and signs as special nonconformities

• Landscaping: a use that is nonconforming only as to landscaping may continue indefinitely, but if improvements exceed 50% of total appraised value, landscaping must be upgraded per Chapter 18.36; any change/expansion should improve landscaping to the maximum extent possible.
• Off-street parking/loading: existing shortfalls may continue indefinitely; however, any change, expansion, or intensification must provide the incremental additional parking/loading required by Chapter 18.38.
• Signs: nonconforming signs follow § 18.44.200, including amortization/removal timelines for certain off-site signs and limits on alterations.

For broader standards and triggers, see parking, landscaping and screening, and signage.

Wireless facilities and nonconformity

• Nonconforming communications facilities that support emergency services may be expanded with a Conditional Use Permit and specific findings, up to 100% of original floor area.
• When discontinued, wireless equipment must be removed within 30 days and the site restored.

How permits and prior approvals affect status

• If a use lawfully existed without a discretionary permit that would now be required, it is deemed conforming but only to the extent of the prior lawful operation (e.g., same boundaries/hours). If a use was authorized by a CUP/Administrative Permit that the code no longer allows, it may continue, but only under its original conditions.
• Expansions or modifications of legal nonconforming uses must meet all applicable current provisions.

For the review path on expansions and changes, see design review and overlay districts where applicable.

ADUs on properties with other nonconforming conditions (state overlay)

• The County’s ADU chapter includes a narrow “nonconforming conditions” enforcement delay clause for ADUs/JADUs receiving violation notices (Health & Safety Code § 17980.12).
• Separately, California’s ADU law limits a local agency’s ability to deny ADUs due to existing zoning nonconformities, except for documented health/safety conflicts affected by the ADU construction. See California ADU law.

Decision-critical rules at a glance

Checklist

• Confirm your site is in the unincorporated areas and identify the base zoning and any overlays via the County’s zoning & planning overview and overlay districts.
• Assemble proof that the use/structure/parcel/sign was lawfully established (dated permits, COs, deeds, utility bills, receipts). Submit to the Director for a legal nonconformity determination.
• Verify there has been no cessation for 180 consecutive days; gather evidence of continuous operation if applicable.
• If planning changes, expansions, or intensification, design them to meet current development standards and provide any incremental parking required.
• For structures, check the 50% valuation thresholds and any “Residential Exceptions” that might apply. Coordinate early on valuation methodology.
• If you hold a prior CUP/Admin Permit, operate strictly within its conditions; expansions must meet current code or secure new approvals.
• If signs are involved, plan for compliance or removal timelines under the nonconforming sign rules.
• If your project triggers discretionary review, expect consistency checks during design review; consider relief tools under variances and exceptions where applicable.

Risks & Ambiguities

Plain-English Summary

If you’re in the unincorporated areas and your building, lot, sign, or use was legal when created but no longer matches today’s rules, you can usually keep it as-is. But Merced County will end your nonconforming status if you stop the use for 180 days, if damage passes the 50% line without full code compliance on rebuild, or if you try to expand without meeting today’s standards. Get your paperwork in order and talk with Planning before you make changes.

Source References

• § 18.90.010 Purpose/Intent/Definitions; § 18.90.020 Proof of Legal Status; § 18.90.030 Continuation; § 18.90.040 Termination of Nonconformities
• § 18.92.010–.030 Nonconforming Parcels (buildable status, subdivision, merger)
• § 18.94.010–.030 Nonconforming Structures; Residential Exceptions; § 18.94.020 Destruction
• § 18.96.010–.040 Nonconforming Uses (continuation, CUP/Admin permit effects, expansion/modification, discontinuance)
• § 18.98.010–.030 Other Specific Nonconforming Provisions (landscaping, parking/loading, signs) and § 18.44.200 Nonconforming Signs
• § 18.68.110 Wireless Facility Discontinuance and Site Restoration
• State overlay for ADUs related to nonconforming conditions: California ADU Handbook excerpts (Gov. Code refs)

Retrieved passages

• Merced County Zoning Code (§ 2) High relevance show source text
• CFC § 2 (section shall) High relevance show source text
• Merced County Zoning Code (article that) High relevance show source text
• CFC § 2 (§ 2) High relevance show source text
• CBC § 2 (§ 2) High relevance show source text
• Merced County Zoning Code (§ 2) High relevance show source text
• Merced County Zoning Code (section shall) High relevance show source text
• Merced County Zoning Code (§ 2) High relevance show source text

Cited sections

• § 18.90.010 Purpose/Intent/Definitions; § 18.90.020 Proof of Legal Status; § 18.90.030 Continuation; § 18.90.040 Termination of Nonconformities (§ 18.90.010)
• § 18.92.010–.030 Nonconforming Parcels (buildable status, subdivision, merger) (§ 18.92.010)
• § 18.94.010–.030 Nonconforming Structures; Residential Exceptions; § 18.94.020 Destruction (§ 18.94.010)
• § 18.96.010–.040 Nonconforming Uses (continuation, CUP/Admin permit effects, expansion/modification, discontinuance) (§ 18.96.010)
• § 18.98.010–.030 Other Specific Nonconforming Provisions (landscaping, parking/loading, signs) and § 18.44.200 Nonconforming Signs (§ 18.98.010)
• § 18.68.110 Wireless Facility Discontinuance and Site Restoration (§ 18.68.110)
• State overlay for ADUs related to nonconforming conditions: California ADU Handbook excerpts (Gov. Code refs)
• MercedCounty_ZoningCode.md
• 2025 California ADU handbook.md

• Official Merced County code library