Local zoning · San Leandro

San Leandro — Nonconforming Uses

Q: If my business stops operating, how long before it's considered abandoned?

If a nonconforming use is substantially discontinued for 180 calendar days or more, it cannot be re‑established (there is a nonconforming dwelling exception) — see § 4.20.112 .

Q: My building burned — can I rebuild the nonconforming structure?

If damage is 50% or less (per Building Official valuation) you may restore the structure and resume the nonconforming use if permits are filed within six months; if damage exceeds 50% , you generally must rebuild in full conformance unless a narrow exception applies ( § 4.20.116 ) .

Q: Are there deadlines for fixing nonconforming site features (screening, paving)?

Yes: for sites in C, P, or I districts that lack required screening, paving, or planting, the applicant must submit a schedule to eliminate or substantially reduce those nonconformities within five years as part of a building permit application ( § 4.20.120 ) .

Q: Do residential nonconforming buildings have different rules than commercial ones?

Yes. Residential structures in R districts have specific restoration exceptions (e.g., reconstruction with same floor area even if damage exceeds 50% ) and single‑family/two‑family enlargements may be allowed with a use permit and findings — see § 4.20.116 and § 4.20.108(A)(4) .

Q: Who makes the call on what increases the "degree of nonconformity"?

The Zoning Enforcement Official evaluates whether proposed alterations increase the area or degree of nonconformity and may approve minor tenant improvements that do not increase nonconformity; larger increases may require a variance or use permit as described in § 4.20.108 .

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

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Last reviewed: July 2, 2026

Overview

San Leandro controls nonconforming uses and structures through Chapter 4.20 of the municipal code. The ordinance lets legally existing nonconforming uses and buildings continue in limited ways, prohibits enlargement or re‑establishment after abandonment in many cases, and creates special procedures (including an N amortization overlay) to terminate or phase out nonconformities over time. See the city’s zoning map and base-district rules for how these rules apply to a particular parcel; for citywide district summaries see the San Leandro zoning & planning overview and the San Leandro Zoning pages.

How San Leandro treats nonconformities (key rules)

Continuation and routine maintenance of a lawfully existing nonconforming use or structure is allowed, subject to limits in Chapter 4.20 (see § 4.20.104) .
Nonconforming uses generally may not be enlarged, moved, or extended; minor tenant improvements that do not increase the degree or area of nonconformity can be approved by the Zoning Enforcement Official (§ 4.20.108) .
Abandonment: a nonconforming use discontinued for 180 calendar days or more cannot be re‑established (except nonconforming dwelling units) (§ 4.20.112) .
Restoration after destruction: structures damaged 50 percent or less (valuation basis) can be restored and the nonconforming use resumed if permits and timing requirements are met; greater than 50 percent damage requires full conformance when reconstructed, with narrowly drawn residential/commercial exceptions (§ 4.20.116) .
Abatement/amortization: the city may require discontinuance of nonconforming uses on a timetable; an N Nonconforming Use Overlay (-N) may be adopted to set a different amortization schedule (§ 3.24.104–120 and § 4.20.124) .
Some on‑site technical nonconformities (screening of equipment, paving, planting areas) must be phased out by an agreed schedule before building permits will be issued (§ 4.20.120) .

Below is a quick table of the most decision‑relevant nonconforming rules.

What it is	Key rule / limit	Code Reference
Continuation / maintenance of nonconforming use/structure	May be continued and maintained; routine repairs allowed	§ 4.20.104
Expansion of nonconforming use	Prohibited except limited exceptions; no increase in area/hours	§ 4.20.108
Abandonment (re‑establishment)	Discontinued ≥ 180 days → cannot be re‑established (dwelling units exempt)	§ 4.20.112
Damage/destruction threshold	≤ 50% repairable and may be restored with timely permit; >50% must conform (limited exceptions)	§ 4.20.116
Amortization / overlay	City may create -N overlay and set alternate termination timetable	§ 3.24.108–120
Building permits where site features nonconform	Must submit schedule to eliminate nonconformities within 5 years for C, P, I sites	§ 4.20.120
Time to terminate nonconforming uses	Many commercial/industrial nonconforming uses: 7 years after notice unless excepted	§ 4.20.124

District-by-district breakdown (how nonconforming rules interact with San Leandro districts)

Below are San Leandro district summaries focused on nonconforming issues. For general district maps and a full list of permitted uses consult the San Leandro Zoning page and the city’s base district regulations.

RS, RS-40, RS-VP (single-family residential subdistricts)

Purpose: conventional single‑family neighborhoods and variants with view protection (RS-VP) and larger lot versions (RS-40)—see base district tables in Chapter 2.04. Notwithstanding the base uses, nonconforming residential structures and uses are explicitly allowed to be maintained per Chapter 4.20 (§ 4.20.104) .
Typical permitted uses: single‑family dwellings, accessory structures (see base district regs); home occupations require separate permit (§ 2.04.220) .
Key dimensional standards relevant to nonconforming structures:
- Daylight Plane rules apply in RD, RO, RS, RS-40, and RS-VP and limit bulk/height envelopes; these interact with nonconforming height situations and the exceptions in Chapter 4.20 (§ 2.04.324) .
- Maximum lot coverage: RO 33‑1/3%, RS 50%, RS-40 50%, RS‑VP 50% — useful when assessing whether an addition would increase nonconformity (§ 2.04.328) .
Where it applies: mapped residential neighborhoods (verify zoning map). Preexisting residential nonconformities in R districts are expressly allowed to be maintained; reconstruction rules allow same floor area replacement even when damage exceeds 50%, subject to administrative review, provided no increase in nonconformity (§ 4.20.116) .

(First mention of the city's development standards is here: see San Leandro Development Standards.)

RO (residential-office or residential‑office mixed)

Purpose and uses: hybrid/residential-office contexts; consult base district regulations for permitted uses and the Daylight Plane and lot coverage rules that apply to RO (§ 2.04.324; § 2.04.328) .
Nonconforming structure rules: same Chapter 4.20 limits on enlargement, relocation, and reconstruction apply (no increase in discrepancy to front/side/rear yards, height, floor area, etc.) (§ 4.20.108) .

C (Commercial) — including commercial base districts

Purpose: commercial activity nodes (see base regs for C subtypes). Nonconforming commercial uses in C districts must follow Chapter 4.20; commercial nonconforming uses located in residential zoning face tighter restoration/use permit requirements (§ 4.20.116) .
Building permits: if a site in C is nonconforming for screening, paving, planting, or outdoor storage, applicants must submit a schedule to eliminate those nonconformities within 5 years before building permits are issued (§ 4.20.120) .

(First mention of parking rules linked here: San Leandro Parking.)

P (Public), I (Industrial), NA, SA (Neighborhood / Special Activity)

Purpose & uses: institutional/public (P), industrial (I), neighborhood activity (NA), and special activity (SA) districts are governed by base district regulations; where nonconformities exist the same Chapter 4.20 framework applies.
Time to termination: nonconforming uses located in C, P, NA, SA, and I districts are subject to a 7‑year discontinuance period from the date of notification unless excepted by the procedure in § 4.20.124 (§ 4.20.124.B.1) .
Where it applies: municipal institutional, industrial, and commercial zones; check the zoning map for parcel designation.

(First mention of Overlay Districts is here: San Leandro Overlay Districts.)

-N Nonconforming Use Overlay District

Purpose: the N (-N) overlay is expressly created to allow the city to set alternative amortization/termination schedules to accelerate conversion to conforming uses where numerous nonconforming uses occupy an area (§ 3.24.104–120) .
How it works: the overlay is added to a base zone with the “-N” suffix on the zoning map and the Council adopts the amortization timetable by ordinance; findings and adoption procedures are prescribed in § 3.24.112–120 .
Practical: if your property is in a -N area you may face shorter termination dates than the standard 7-year timetable—check the zoning map and the ordinance that established any -N district.

(First mention of Design Review is here: San Leandro Design Review.)

Practical guidance (synthesis)

Do not assume a nonconforming commercial use can be expanded — expansion is generally prohibited and will require either a valid exception (narrow, e.g., single‑family/two‑family exception) or a use permit; see § 4.20.108(A)(4–5) for residential and certain assembly exceptions and the Planning Commission findings required .
If a nonconforming use stops for 180 days or longer, it cannot be restarted (burden of proof to show otherwise is on the operator) — plan occupancy and business interruptions accordingly (§ 4.20.112) .
If the structure is damaged, know the 50% valuation test: under § 4.20.116, ≤50% damaged → restoration generally allowed (with a building permit filed within six months); >50% → reconstruction must conform unless a narrow exception applies .
For site technical nonconformities (screening, paving, planting), expect the city to ask for a time‑bound mitigation schedule (≤5 years) before new permits are issued (§ 4.20.120) .
If your parcel is in an -N overlay, check the overlay ordinance to confirm the amortization period — the overlay supersedes the standard abatement schedule (§ 3.24.120) .

(First mention of ADUs and California ADU law is here: San Leandro ADUs and California ADU law; California Building Standards Code link: California Building Standards Code.)

Checklist — what an applicant must satisfy (practical step list)

Confirm the parcel’s base district and any overlays on the zoning map (verify presence of -N, -L, or other overlays). Verify with the jurisdiction.
Determine whether the use/structure was lawfully established before the ordinance change and whether it qualifies as a nonconforming use or nonconforming structure per § 4.20.104 .
If proposing alterations, confirm the proposal does not increase the degree of nonconformity or exceed the 50% cumulative cost test; if it does, prepare for a variance or use permit per § 4.20.108 and related variance rules .
For restoration after damage: obtain a building permit within 6 months if ≤50% damaged; prepare valuation evidence for the Building Official to determine the damage ratio per § 4.20.116 .
If notified of nonconformity, consider applying for an exception (Planning Commission public hearing) within the two‑year application window described in § 4.20.124.C if you wish to avoid termination timelines .
If the site is nonconforming for screening/paving/planting and you need a building permit, submit a mitigation schedule for elimination or substantial reduction within 5 years as required by § 4.20.120 .
Coordinate discretionary approvals (use permits, variances, administrative review) with Planning and the Zoning Enforcement Official; site changes may trigger Site Plan Review or Design Review requirements (see San Leandro Design Review and San Leandro Development Standards).

Risks & Ambiguities

Issue	Why it matters	What to verify
Amortization by -N overlay	Overlay can shorten termination periods and require conversion	Confirm whether your property carries a -N designation and read the adopting ordinance for the amortization period (§ 3.24.108–120)
Valuation for 50% test	Whether restoration is permitted hinges on the Building Official’s damage valuation	Obtain pre‑ and post‑damage estimates and talk to the Building Official about valuation methodology under § 4.20.116
Whether a proposed tenant improvement “increases degree of nonconformity”	Zoning Enforcement Official can allow minor changes but definitions are case‑specific (§ 4.20.108.A.2)	Ask for a pre‑application determination from the Zoning Enforcement Official; document that area/hours/nonconforming metrics won’t increase
Residential exceptions vs. commercial limits	Single‑family/two‑family exceptions exist for enlargements; other residential types don’t get the same flexibility	If your property is SFR or duplex, confirm which exception applies under § 4.20.108(A)(4); for other residential forms verify limits in § 4.20.116
Site‑feature nonconformities blocking permits	City can withhold building permits unless a 5‑year correction schedule is accepted (§ 4.20.120)	If screening/planting/paving are nonconforming, prepare a mitigation schedule and cost estimate for approval by the Zoning Enforcement Official

Plain-English Summary

If your San Leandro building or business was legal when it started but now conflicts with the zoning rules, you can usually keep it — but you cannot make it bigger or restart it after long abandonment, and the city can require a timetable for converting to conforming uses or force discontinuance under an amortization overlay. See the specific code sections cited and check your parcel’s zoning and overlays to know exactly which rules apply.

Source References

San Leandro Municipal Code — Chapter 4.20 Nonconforming Uses and Structures: § 4.20.100, § 4.20.104, § 4.20.108, § 4.20.112, § 4.20.116, § 4.20.120, § 4.20.124. See citations in code preview . (Code hosted at https://ecode360.com/SA5044)
N Nonconforming Use Overlay — § 3.24.104–120 (purpose, adoption, and alternative amortization schedules) .
Residential daylight plane and lot coverage rules (impact on nonconforming structures) — § 2.04.324 and § 2.04.328 .
Base district notes and administrative/site review references — Chapter 2.04 and Article 3 administrative regs (see excerpts) .

Sources

Retrieved passages

San Leandro Zoning Code (§ 1) High relevance
San Leandro Zoning Code (§ 1) High relevance
CBC § 1 (§ 1) High relevance
San Leandro Zoning Code (section shall) High relevance
San Leandro Zoning Code (§ 4.20.116) High relevance
San Leandro Zoning Code (chapter shall) High relevance
San Leandro Zoning Code (§ 4.20.108) High relevance
San Leandro Zoning Code (Section 4.04.340) High relevance

Cited sections

Official San Leandro code library

Frequently asked questions

What makes a use or structure "nonconforming" in San Leandro?

A use or structure lawfully established before a zoning change that now violates current use regulations, lot area per dwelling, or dimensional standards is a nonconforming use or nonconforming structure and may be continued subject to limits in § 4.20.104 .

Can I expand a nonconforming commercial business in San Leandro?

Generally no. A nonconforming use may not be enlarged, extended, or moved so as to increase the nonconformity; only limited minor alterations that do not increase the area or degree of nonconformity can be approved administratively (see § 4.20.108) .

If my business stops operating, how long before it's considered abandoned?

If a nonconforming use is substantially discontinued for 180 calendar days or more, it cannot be re‑established (there is a nonconforming dwelling exception) — see § 4.20.112 .

My building burned — can I rebuild the nonconforming structure?

If damage is 50% or less (per Building Official valuation) you may restore the structure and resume the nonconforming use if permits are filed within six months; if damage exceeds 50%, you generally must rebuild in full conformance unless a narrow exception applies (§ 4.20.116) .

What if my property is in an **-N** Nonconforming Use Overlay?

An -N overlay changes the amortization/termination timetable for multiple nonconforming uses and can shorten the time before termination; the overlay is shown as a “-N” on the zoning map and its ordinance states the applicable amortization period (§ 3.24.108–120) .

Are there deadlines for fixing nonconforming site features (screening, paving)?

Yes: for sites in C, P, or I districts that lack required screening, paving, or planting, the applicant must submit a schedule to eliminate or substantially reduce those nonconformities within five years as part of a building permit application (§ 4.20.120) .

Could I substitute one nonconforming use for another?

Possibly — substitution is allowed only if the prior nonconforming use has not been discontinued for 180 days and the new use is of lesser nonconformity as determined by the Zoning Enforcement Official (§ 4.20.112.B) .

If I want to keep a nonconforming use long-term, what administrative route exists?

Property owners may apply for an exception to the termination provisions; the Planning Commission holds a public hearing and may recommend an exception to the City Council under procedures in § 4.20.124.C (application materials and findings required) .

Do residential nonconforming buildings have different rules than commercial ones?

Yes. Residential structures in R districts have specific restoration exceptions (e.g., reconstruction with same floor area even if damage exceeds 50%) and single‑family/two‑family enlargements may be allowed with a use permit and findings — see § 4.20.116 and § 4.20.108(A)(4) .

Who makes the call on what increases the "degree of nonconformity"?

The Zoning Enforcement Official evaluates whether proposed alterations increase the area or degree of nonconformity and may approve minor tenant improvements that do not increase nonconformity; larger increases may require a variance or use permit as described in § 4.20.108 .

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