Local zoning · Alpine County

Alpine County — Nonconforming Uses

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

Last reviewed: July 6, 2026

Overview

This page explains how nonconforming uses, nonconforming structures, and nonconforming lots are treated under Alpine County’s Zoning Ordinance (Title 18) in the unincorporated areas. The rules apply countywide across base zoning districts and combined/overlay areas, and are administered in harmony with the General Plan and official zoning maps. If you’re evaluating a property’s status or planning a change, start with the nonconforming standards below and confirm the property’s zoning and any applicable overlays under the county’s zoning framework.

Plain-English key: A lawful nonconforming use or structure may continue, but it generally cannot be enlarged or intensified unless a specific process in Chapter 18.72 authorizes it (§ 18.72.040 ).

What “nonconforming” means in Alpine County

Definitions come from Chapter 18.08: a nonconforming lot is smaller than current minimums but is “lawful” if it is a lot of record existing before January 1, 1964 (§ 18.08.555; related legal-building-site rule in § 18.68.020.D ). A nonconforming structure met the rules when built but no longer complies (§ 18.08.560 ). A nonconforming use is a use that was legal when established, has been continuous, but isn’t currently listed as permitted in the district (§ 18.08.570 ).
Chapter 18.72 governs how nonconformities may continue, be altered, or be phased out (§§ 18.72.010–18.72.100 ).

Core nonconforming standards (Title 18)

Purpose and applicability. Chapter 18.72 regulates nonconforming uses, structures, and lots that were lawfully established (§§ 18.72.010–.020 ).
Continuation. Lawful nonconforming uses and structures may continue and be maintained, but no enlargement/alteration is allowed except as provided in Chapter 18.72 (§ 18.72.040 ).
Routine work. Maintenance, repairs, and interior alterations of nonconforming structures are allowed (§ 18.72.050 ).
Additions to nonconforming structures. Allowed only if the addition itself fully meets current district standards and does not increase the degree of nonconformity (§ 18.72.060.A ).
Second dwelling units and accessory buildings. A second dwelling unit compliant with Chapter 18.69 may be added on a lot with a nonconforming primary dwelling; accessory buildings are allowed if they meet district standards unless a variance under Chapter 18.80 is granted (§ 18.72.060.B ). For broader state ADU rights and limits on conditioning approvals due to existing nonconformities, see California ADU law (state guidance notes local agencies generally can’t deny ADUs solely to correct unrelated nonconforming zoning conditions where no health/safety risk is posed; Gov. Code §§ 66321–66323; HCD 2025 ADU Handbook ).
Decks and uncovered porches. A nonconforming deck may be removed and rebuilt if not enlarged and if the nonconforming setback is not reduced (§ 18.72.060.C ).
Restoration after calamity. A lawful nonconforming use/structure destroyed by calamity may be rebuilt in the same location and to the same size/character, if a building permit is obtained within 36 months (extensions possible for good cause) (§ 18.72.070.A–B ).
Expansion of a nonconforming use. Requires a use permit; if the structure itself is not to current building code, the use cannot expand its floor area until the building is brought up to code (§ 18.72.080.A–B ).
Changes/substitutions. The Community Development Director may approve substitution of one nonconforming use with another nonconforming use (no relocation) if findings ensure compatibility, General Plan consistency, and no detriment (§ 18.72.090.B ).
Discontinuance. A nonconforming use discontinued for 5 years may not resume without a use permit (§ 18.72.100 ).

How district rules interact with nonconforming status

Nonconforming standards apply across all districts and overlays in the unincorporated areas. To know what makes a use/structure “nonconforming,” you must know what today’s district requires (purpose, permitted uses, and dimensional standards). Use this quick district-by-district summary, then check the official zoning map and General Plan designation before you rely on the minimums (§ 18.04.060; § 18.12.070; § 18.04.040 ).

AG — Agriculture (AG)

Purpose: Preserve lands for agriculture; buffer from incompatible uses (§ 18.16.010 ).
Typical permitted uses: Agriculture; one single-family dwelling; ranch/farm facilities; home occupations; incidental office; accessory uses; supportive/transitional housing (§ 18.16.020 ).
Key dimensional standards: Minimum parcel area 20 acres; front/side/rear yards 30 ft (§ 18.16.040 ).
Where it applies: Agricultural areas identified by the General Plan; verify district boundaries on the official map (§ 18.12.070 ).

AP — Agricultural Preserve (Williamson Act)

Purpose: Keep contracted lands in long-term ag production; restrict non-ag uses (§ 18.18.010 ).
Typical permitted uses: Agriculture; one single-family dwelling per 100-acre parcel; home occupations; incidental office; accessory uses; supportive/transitional housing (§ 18.18.020 ).
Key dimensional standards: See AP chapter and any contract conditions; other general standards in Chapter 18.68 also apply (§ 18.18.070 ).
Where it applies: Williamson Act contracted lands; verify with the County and Assessor (AP contracts overlay the zoning).

LP — Land Preserve

Purpose: Keep open space in a largely undeveloped state; allow controlled resource-based uses (§ 18.20.010 ).
Typical permitted uses: Public parks; private open space; agriculture (§ 18.20.020 ).
Key dimensional standards: Governed by Chapter 18.68 and parcel-specific context; confirm with the County.
Where it applies: Open-space areas per General Plan; check the official map (§ 18.12.070 ).

TP — Timber Preserve

Purpose: Preserve timberlands under state TP provisions (§ 18.24.010 ).
Typical permitted uses: Timber growing/harvest; watershed and habitat management; grazing; pre-existing dwellings when zoned TP (§ 18.24.020 ).
Key dimensional standards: Use intensity governed by TP restrictions; one dwelling per 160-acre minimum with a use permit (owner-occupied) (§ 18.24.030.D ).
Where it applies: TP-enrolled lands; confirm on the official map and with the Assessor.

RE — Residential Estate

Purpose: Low-density single-family and mini-ranch areas (§ 18.32.010 ).
Typical permitted uses: One single-family dwelling; home occupations; livestock; accessory structures; supportive/transitional housing (§ 18.32.020 ).
Key dimensional standards: County sets minimum parcel size case-by-case, but not below the site’s General Plan minimum; typical yards: front/side/rear 30 ft (§ 18.32.040 ).
Where it applies: Large-lot residential; verify on the official map.

RN — Residential Neighborhood

Purpose: Organized urban/suburban neighborhoods; base density up to 4 units/acre unless RH GP designation with UP allows more (§ 18.36.010 ).
Typical permitted uses: One single-family dwelling; home occupations; accessory structures; limited livestock; supportive/transitional housing (§ 18.36.020 ).
Key dimensional standards: Minimum lot size set by County per site and GP; width 80 ft, depth 100 ft; front 30 ft; side 30 ft (street side on corners 30 ft; interior 20 ft); rear 20 ft (§ 18.36.040 ).
Where it applies: Platted neighborhoods; verify on the official map.

C — Commercial

Purpose: Community business districts.
Typical permitted uses: Retail, offices, restaurants (fast food is conditional), hotels/motels for transient guests, quasi-public uses; accessory/living quarters accessory to a permitted use; emergency shelters (§ 18.44.020 ).
Key dimensional standards: Lot area 5,000 sf; width 50 ft; front yard 6 ft; side/rear yards generally none unless next to residential (then residential yard standards or rear 20 ft); height up to 3 stories/45 ft (§§ 18.44.050–.060 ).
Where it applies: Community commercial nodes; verify on the official map.

IND — Industrial

Purpose: Provide and protect locations for industrial development, including uses that would be objectionable elsewhere (§ 18.48.010 ).
Typical permitted uses: Broad commercial/industrial/warehouse uses; many heavier uses require a use permit (§§ 18.48.020–.030 ).
Key dimensional standards: Lot area 1 acre; front 20 ft; side/rear none unless abutting another zone (then 50 ft); maximum height 45 ft (§§ 18.48.040–.050 ).
Where it applies: Industrial-designated areas; verify on the official map.

INS — Institutional

Purpose: Sites for public agencies/utilities and community facilities (§ 18.52.010 ).
Typical permitted uses: Quasi-public and public uses, utilities; some unrelated uses and airports by use permit (§§ 18.52.020–.030 ).
Key dimensional standards: Front 30 ft; side 20 ft; rear 20 ft; height up to 50 ft (special edge rules if abutting R zones) (§ 18.52.040–.050 ).
Where it applies: Public facility sites countywide; verify on the official map.

PD — Planned Development

Purpose: Implement a comprehensive development plan that clusters development and preserves open space (§ 18.28.010 ).
Uses and standards: Fixed by the approved PD plan; timing and permit rules apply (§§ 18.28.040, 18.28.090–.100 ).
Where it applies: As rezoned/approved; verify PD plan documents and zoning map.

—CR Combined Zone (Commercial Recreation)

Purpose: Allow visitor-serving retail/services at selected highway/resort locations; applied in combination with a base zone (§ 18.64.010 ).
Typical permitted/conditional uses: Recreation-oriented retail; guest cottages; larger resort facilities and campgrounds by use permit (§§ 18.64.020–.030 ).
Standards: Base district controls unless a use permit modifies them (§§ 18.64.040–.050 ).

Note: Countywide general standards in Chapter 18.68 (e.g., development standards such as height and yards) apply alongside the district rules (§§ 18.68.010, 18.68.050, 18.68.140 list ). Separate provisions govern signage—including rules for nonconforming signs (§ 18.74.030.D )—and corridor-specific rules in overlay districts like the Scenic Highway Corridor (§ 18.60.020–.030 ).

Nonconforming quick guide (what most applicants need)

Topic	Rule of thumb	Time-sensitive?	Code Reference
Keep using a lawful nonconforming use	Allowed to continue; no enlargement unless allowed elsewhere in Chapter 18.72	Ongoing	§ 18.72.040.A
Maintain/repair a nonconforming structure	Routine maintenance, repairs, interior alterations OK	Ongoing	§ 18.72.050
Add to a nonconforming structure	Addition must meet all current standards and not increase nonconformity	Ongoing	§ 18.72.060.A
Rebuild after calamity	Rebuild in same location/size/character; get building permit within 36 months (extensions possible)	36 months	§ 18.72.070.A–B
Expand a nonconforming use	Requires a use permit; if building isn’t to building code, no floor area expansion until it is	Case-by-case	§ 18.72.080.A–B
Substitute one nonconforming use for another	Director may approve if strict findings are met; no relocation	Case-by-case	§ 18.72.090.B
Discontinued nonconforming use	After 5 years, resumption requires a use permit	5 years	§ 18.72.100
Nonconforming lot (substandard size)	“Lawful” if it existed before 1/1/1964; also treated as legal building site under general rules	Ongoing	§ 18.08.555; § 18.68.020.D
Second unit on a nonconforming homesite	A second dwelling unit per local Ch. 18.69 may be added if it meets standards (or variance), even if the primary dwelling is nonconforming	Ongoing	§ 18.72.060.B; § 18.69.020–.040

Practical tip: Where exterior changes are proposed, confirm whether design review or corridor standards (e.g., Scenic Highway) apply; these may add objective limits that affect what you can rebuild or add (§ 18.60.020–.030; Markleeville design chapter excerpts § 18.56.100–.120 ).

Checklist

Confirm the property is in the unincorporated areas under the County’s zoning & planning overview (§ 18.04.040 ).
Identify the current base district and any combined/overlays on the official map (§ 18.12.070 ).
Verify the use/structure/lot was lawfully established (check permits, assessor records, recording dates; pre-1964 lots may qualify) (§§ 18.72.020, 18.08.555, 18.68.020.D ).
If proposing an addition, design it to fully meet today’s district standards and avoid increasing any nonconformity (§ 18.72.060.A ).
If a nonconforming deck is being replaced, keep the same size and setbacks (§ 18.72.060.C ).
If expanding a nonconforming use, prepare for a use permit and code-compliance upgrades if the host building is not to current building code (§ 18.72.080.B; consider variances and exceptions where appropriate ).
Track discontinuance periods; don’t let 5 years lapse if you plan to resume (§ 18.72.100 ).
For second units/ADUs on nonconforming sites, cross-check Chapter 18.69 and state California ADU law (§ 18.72.060.B; HCD 2025 ADU Handbook ).
Ensure compliance with any corridor/overlay design and parking standards that apply concurrently (§ 18.60.020–.030; Ch. 18.68 list includes parking and yards ).

Risks & Ambiguities

Issue	Why it matters	What to verify
“Lawfully established” status	Unpermitted work or lapsed approvals could void nonconforming protections	Permit history, inspection records, assessor data (§ 18.72.020 )
36-month rebuild window after calamity	Missed deadline can forfeit the right to rebuild nonconforming use/structure in same place/size	Calendar the deadline; request extensions from the Building Official if needed (§ 18.72.070 )
Increasing “degree of nonconformity”	Even small additions can worsen setbacks/height noncompliance	Design additions to meet current standards; use development standards checklist (§ 18.72.060.A )
Expansion vs. maintenance	Interior remodels are allowed; “expansion” triggers a use permit	Scope, floor area, intensity changes (§§ 18.72.050, 18.72.080.A )
Substitution findings	Director must make multiple compatibility findings to swap uses	General Plan consistency, compatibility, welfare, code compliance (§ 18.72.090.B )
Five-year discontinuance	After five years idle, restarting needs a use permit	Use occupancy/utility records to prove continuity (§ 18.72.100 )
Second units/ADUs on nonconforming lots	Local and state ADU rules limit denial based on unrelated nonconformities	Local § 18.72.060.B; HCD ADU guidance on nonconforming conditions (Gov. Code §§ 66321–66323)
Overlay/design constraints	Scenic/design overlays may further limit exterior work or signage	Corridor map, Chapter 18.60; nonconforming signs rules in § 18.74.030.D

Plain-English Summary

If your place in unincorporated Alpine County doesn’t meet today’s zoning, you can usually keep using it and maintain the building. But you can’t enlarge what’s nonconforming unless you follow Chapter 18.72—additions must meet current rules, expansions of a nonconforming use need a use permit, and rebuilds after disasters must happen within 36 months and match the original size and location. Old, substandard lots can still be “legal” if recorded before 1964. Always cross-check your base zone, any corridor/overlay rules, and whether ADU/second-unit laws give you extra options.

Source References

Alpine County Zoning Ordinance Title 18: General applicability to unincorporated areas (§ 18.04.040) and General Plan relationship (§ 18.04.060)
Official zoning maps and maintenance (§ 18.12.070)
Definitions: nonconforming lot/structure/use (§§ 18.08.555–.570)
Legal building sites and pre-1964 lots (§ 18.68.020.D) and countywide standards (§ 18.68.010, .050, .140 list)
Nonconforming chapter: purpose, applicability, continuation, maintenance, additions, calamity rebuilds, expansion, substitutions, discontinuance (§§ 18.72.010–.100)
Second units/ADUs interplay (§ 18.72.060.B; § 18.69.020–.040)
Scenic Highway Corridor overlay (§ 18.60.020–.030)
Signs (nonconforming signs) (§ 18.74.030.D)
District summaries: AG (§§ 18.16.010–.050) ; AP (§§ 18.18.010–.030, .070) ; LP (§§ 18.20.010–.030) ; TP (§§ 18.24.010–.030) ; RE (§§ 18.32.010–.050) ; RN (§§ 18.36.010–.050) ; C (§§ 18.44.020–.070) ; IND (§§ 18.48.010–.060) ; INS (§§ 18.52.010–.050) ; PD (§§ 18.28.010–.100) ; —CR (§§ 18.64.010–.050)
State ADU constraints on nonconforming conditions (Gov. Code §§ 66321–66323), HCD 2025 ADU Handbook (summary guidance)

Sources

Retrieved passages

Alpine County Zoning Code (Chapter 18.72) High relevance
Alpine County Zoning Code (chapter shall) High relevance
CBC § 3 (Chapter 18.69) High relevance
Alpine County Zoning Code (§ 3.073) High relevance
CBC § 3 (§ 3) High relevance
Alpine County Zoning Code (Chapter 18.72) High relevance
Alpine County Zoning Code (§ 3) High relevance
CBC § 3.064 (§ 3.064) Medium relevance
CBC § 66314 (§ 66314) Medium relevance
Alpine County Zoning Code (chapter may) Medium relevance
Alpine County Zoning Code (section and) Medium relevance
Alpine County Zoning Code Medium relevance
CBC § 2 (§ 2) Medium relevance
Alpine County Zoning Code (§ 9.08) Medium relevance
Alpine County Zoning Code (§ 14.01) Medium relevance
CBC § 105.6 (Chapter 3) Medium relevance
Alpine County Zoning Code (§ 1) Medium relevance
Alpine County Zoning Code (Chapter 18.68) Medium relevance
Alpine County Zoning Code (§ 8.02) Medium relevance
Alpine County Zoning Code Medium relevance
Alpine County Zoning Code (section 21064.3) Medium relevance
Alpine County Zoning Code (§ 7.02) Medium relevance

Cited sections

Alpine County Zoning Ordinance Title 18: General applicability to unincorporated areas (§ 18.04.040) and General Plan relationship (§ 18.04.060) (Title 18)
Official zoning maps and maintenance (§ 18.12.070) (§ 18.12.070)
Definitions: nonconforming lot/structure/use (§§ 18.08.555–.570) (§ 18.08.555)
Legal building sites and pre-1964 lots (§ 18.68.020.D) and countywide standards (§ 18.68.010, .050, .140 list) (§ 18.68.020.D)
Nonconforming chapter: purpose, applicability, continuation, maintenance, additions, calamity rebuilds, expansion, substitutions, discontinuance (§§ 18.72.010–.100) (§ 18.72.010)
Second units/ADUs interplay (§ 18.72.060.B; § 18.69.020–.040) (§ 18.72.060.B)
Scenic Highway Corridor overlay (§ 18.60.020–.030) (§ 18.60.020)
Signs (nonconforming signs) (§ 18.74.030.D) (§ 18.74.030.D)
District summaries: AG (§§ 18.16.010–.050) ; AP (§§ 18.18.010–.030, .070) ; LP (§§ 18.20.010–.030) ; TP (§§ 18.24.010–.030) ; RE (§§ 18.32.010–.050) ; RN (§§ 18.36.010–.050) ; C (§§ 18.44.020–.070) ; IND (§§ 18.48.010–.060) ; INS (§§ 18.52.010–.050) ; PD (§§ 18.28.010–.100) ; —CR (§§ 18.64.010–.050) (§ 18.16.010)
State ADU constraints on nonconforming conditions (Gov. Code §§ 66321–66323), HCD 2025 ADU Handbook (summary guidance) (§ 66321)
AlpineCounty_ZoningCode.md
2025 California ADU handbook.md

Frequently asked questions

Can I expand my nonconforming cabin in unincorporated Alpine County?

Maybe. You can maintain and do interior alterations, but any addition must meet today’s district standards and not increase the nonconformity. Exterior expansion of a nonconforming use requires a use permit (§§ 18.72.050, 18.72.060.A, 18.72.080.A ).

If my nonconforming structure burns down, can I rebuild it?

Yes—if it was lawfully nonconforming and destroyed by calamity, you may rebuild in the same location and to the same size/character by obtaining a building permit within 36 months; the Building Official can grant extensions for good cause (§ 18.72.070.A–B ).

How long can a nonconforming use sit idle before I lose rights?

Five years. After 5 years of discontinuance, you need a use permit to resume any nonconforming use (§ 18.72.100 ).

Does a substandard lot still count as “legal” for building?

Often yes—if the lot was recorded before January 1, 1964 it’s a lawful nonconforming lot and is treated as a legal building site under general rules, subject to all other standards (§ 18.08.555; § 18.68.020.D ).

Can I add a second dwelling unit to a lot with a nonconforming primary house?

Locally, a second dwelling unit that complies with Chapter 18.69 may be allowed on a lot with a nonconforming primary dwelling, but it must meet current standards unless a variance is granted (§ 18.72.060.B; § 18.69.020–.040 ). State ADU law also limits denial based on unrelated nonconforming conditions (see HCD guidance cited above).

Do corridor/overlay rules affect what I can rebuild or replace?

They can. Scenic Highway Corridor standards apply where visible from designated corridors and can restrict certain activities; signage has separate nonconforming rules. Confirm applicable overlays before planning work (§ 18.60.020–.030; § 18.74.030.D ).

What setbacks and heights apply if I’m rebuilding a nonconforming structure?

Rebuilds after calamity must match the original location and size/character to remain nonconforming. New additions must meet current district setbacks/heights and cannot worsen nonconformities (§§ 18.72.060.A, 18.72.070.A–B; see district standards above ).

Who decides if I can swap one nonconforming use for another?

The Community Development Director may approve a substitution (no relocation) if strict findings are met on legality, General Plan consistency, compatibility, and public welfare (§ 18.72.090.B ).

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