Local zoning · Burlingame

Burlingame — Nonconforming Uses

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

Last reviewed: July 1, 2026

Overview

Burlingame’s Zoning Ordinance (Title 25) treats nonconformities as legally established lots, structures, or uses that no longer meet current zoning rules because the Code or map changed after they were lawfully created. The rules let lawful nonconformities continue in a limited way while restricting expansion, requiring proof of legal status, and setting firm triggers for when nonconforming rights end (for example abandonment or substantial destruction). See the general nonconforming provisions in § 25.50.010 and the chapters specific to nonconforming lots, structures, and uses in Chapters 25.52, 25.54, and 25.56 for the controlling standards.

Note: when you need to show or change off‑site parking, consult Burlingame’s rules for parking because nonconforming parking has its own rules.

How the Code is organized for nonconformities (quick map to rules)

General nonconforming provisions and proof/maintenance: § 25.50.010 – § 25.50.060.
Nonconforming lots: Chapter 25.52 (especially § 25.52.010 – § 25.52.020).
Nonconforming structures: Chapter 25.54 (notably § 25.54.010 – § 25.54.050, and § 25.54.040 for residential exceptions).
Nonconforming uses: Chapter 25.56 (notably § 25.56.010 – § 25.56.050).
Other nonconforming elements (parking, fences, landscaping): Chapter 25.58 (see § 25.58.010–.030).

You will likely need to coordinate with the Planning Director or the Planning Commission for determinations, appeals, revocations, or special permits; those procedures are in the permit and appeals chapters. See also the City’s rules on design review, overlay districts, and variances & exceptions.

District‑by‑district breakdown (how nonconforming rules interact with actual districts)

Note: below each district name is bolded and linked where it is natural to mention the topic; the descriptions synthesize the Burlingame Code — consult the cited § for precise language.

R-1 (Single‑Unit Residential)

Purpose & where it applies: § 25.10 establishes the R-1 district for single unit neighborhoods; development standards and allowed uses are in Table 25.10‑1 and related tables.
Typical permitted uses: single‑family dwellings, small home occupations, public parks, limited institutional uses (see Table 25.10‑1).
Key dimensional standards (examples): maximum heights, setbacks, FAR and lot coverage for R‑districts are set in Table 25.10‑2 (see § 25.10.030). Legal nonconforming single‑unit dwellings that already met R‑1 standards are treated specially in mixed‑use districts (see CMU/BRMU).
Nonconforming interaction: Single‑unit dwellings that are lawful but don’t meet other district standards may be continued, and single‑unit residences have a rebuilding exception under § 25.54.040.A allowing reconstruction to pre‑existing size/dimensions after catastrophic loss (but nonconforming uses in that structure cannot continue).

R-2 / R-3 / R-4 (Multi‑unit Residential)

Purpose & where it applies: Chapters for R‑2, R‑3, R‑4 are in Chapter 25.10. Standards for density, FAR, and open space differ by district.
Typical uses: duplexes, multi‑unit dwellings, supportive housing (subject to rules in Article 4/25.48).
Nonconforming interaction: Multi‑unit residential nonconforming structures have a specific reconstruction allowance in § 25.54.040.B: following involuntary destruction, multi‑unit residential structures (except in I‑I) may be rebuilt with the same footprint, height, and number of dwelling units, subject to Building/Fire Code and state statutes (see § 25.54.040).

California Drive Mixed‑Use (CMU) and Broadway Mixed‑Use (BRMU)

Purpose & where it applies: § 25.14.010 – § 25.14.060 describe mixed‑use districts; CMU is for pedestrian‑scale neighborhood commercial; BRMU preserves a retail pedestrian corridor on Broadway.
Typical permitted uses: ground‑floor retail/service, upper‑story residential, office (see Table 25.14‑1).
Key dimensional points: CMU/BRMU development standards (height, FAR, setbacks) are in Table 25.14‑6 (see § 25.14.060). CMU/BRMU have special rules recognizing that some legal single‑unit dwellings are not subject to Article 5 nonconformity procedures while they continue to meet R‑1 standards.
Nonconforming interaction: In BRMU, the Code explicitly grants an exception for parking replacement after total catastrophe when rebuilding to pre‑loss size and dimensions provided the same amount of parking is on site (see § 25.54.030.C and § 25.58.010.B).

North Rollins Road Mixed‑Use (RRMU) and North Burlingame Mixed‑Use (NBMU)

Purpose & where it applies: RRMU and NBMU are transit‑oriented mixed‑use districts with tiered intensities; uses and tiers and development standards are listed in § 25.14.020 – § 25.14.050 and related tables (RRMU Table 25.14‑2, NBMU Table 25.14‑4).
Typical uses: live/work, small‑scale industry, higher‑intensity residential, offices (see Table 25.14‑1).
Key dimensional standards: tiered heights, FAR, and density vary by tier (examples: RRMU base 40 ft up to 80 ft at max tier; see Table 25.14‑2).
Nonconforming interaction: Established industrial uses in RRMU can remain conforming (explicit), and the Code contemplates reallocation of FAR within a property so long as the degree of nonconformity is not increased (§ 25.54.010.B.1.b).

Downtown & Business Districts (BAC, BMU, CAC, CAR, DAC, HMU, MMU)

Purpose & where it applies: Downtown districts and their use tables are in Chapter 25.16; downtown standards (lot coverage, setbacks, open space requirements) are summarized in Table 25.16‑2 and associated sections.
Typical permitted uses: a broad range of retail, service, office, limited lodging, and mixed‑use development subject to ground‑floor retail requirements in certain districts.
Nonconforming interaction: Nonconforming structures and uses in downtown zones are governed by the same Article 5 rules; nonconforming parking may continue except when a change/intensification triggers additional parking requirements per § 25.58.010.A.

Innovation Industrial (I‑I) and other industrial districts

Purpose & where it applies: Industrial districts provide for manufacturing, warehousing, research and related uses; see Chapter 25.14 and Table 25.14‑1 for where industrial uses are permitted.
Nonconforming interaction: Multi‑unit residential reconstruction exception in § 25.54.040.B specifically excludes the I‑I district (i.e., multi‑unit residential nonconforming buildings in I‑I do not get that reconstruction relief).

Key standards & decision‑relevant points (table)

Topic	What the Code requires / allows	Code reference
Continuation of nonconforming uses	Lawful preexisting uses may continue, subject to limitations on expansion and intensity.	§ 25.56.010
No expansion within structure	A nonconforming use cannot be physically extended beyond its current space, except for minor alterations or changes that themselves conform.	§ 25.56.020.A
Change of use from a nonconforming use	Director may allow change to a similar nonconforming use if it won’t adversely affect neighbors; converting to a conforming use is permanent (no return to nonconforming).	§ 25.56.030
Abandonment threshold	Discontinuance for 180 consecutive days causes loss of nonconforming rights unless active marketing/permit work extends activity per Code.	§ 25.56.040.A
Destruction limit (structure)	If damaged/destroyed ≥ 50% of market value, may only be rebuilt in compliance with current zoning (with residential exceptions).	§ 25.54.030.A
Multi‑unit residential rebuild exception	Multi‑unit residential structures (except in I‑I) may be rebuilt to the same footprint, height and number of units after involuntary destruction (subject to Building/Fire codes and state law).	§ 25.54.040.B
Nonconforming lots	Nonconforming (substandard) lots may continue to be used indefinitely but may not be modified to increase nonconformity; lot mergers/adjustments encouraged.	§ 25.52.010–.020
Nonconforming parking	Parking nonconformities may continue indefinitely, but additional parking is required if a use changes or intensifies (special BRMU exception for total destruction).	§ 25.58.010

Practical guidance / plain‑English synthesis (how the rules play out)

Burden of proof is on the property owner: if you claim a protected nonconforming status you must submit evidence to the Director and that determination is appealable. See § 25.50.040.
Don’t plan to expand: a nonconforming use cannot be enlarged or increased in intensity (for example more seats, longer hours, or additional customer service areas) unless the proposed change itself complies with current Title 25 standards; small repairs are OK. See § 25.56.020.
Watch the 50% rule: If your building is more than 50% destroyed by value, you generally lose the ability to rebuild to the old nonconforming configuration (exceptions for single‑family homes and multi‑unit residentials as specified). See § 25.54.030 and § 25.54.040.
Nonconforming lots can continue but you cannot legally make them more nonconforming; if possible, merge or adjust lot lines to cure the condition (§ 25.52.020).

When working on a nonconforming property you will often need to coordinate with Design Review (especially in commercial and downtown districts) — refer to the City’s design review process early. Also expect sign changes to require Director approval under the nonconforming rules (see § 25.50 for sign treatment) and consider signage rules.

If your project touches landscaping, buffers, or fences, see the landscaping and screening and fence rules — the Code allows some nonconforming landscaping and fences to continue but requires upgrades on expansions.

If you’re proposing an accessory dwelling unit (ADU) on a property with nonconforming zoning elements, state ADU law limits the city’s ability to require correction of nonconforming zoning conditions; consult Burlingame’s ADU page and state law guidance for interplay. Notwithstanding, verify with the jurisdiction how local nonconforming structure rules (like the 50% threshold) interact with ADU approvals.

Checklist (what an applicant must satisfy when claiming or working with a nonconformity)

Prepare documentary proof of lawful pre‑existing condition (permits, dated plans, business license history) for a Director determination (owner bears burden). § 25.50.040.
Confirm whether the requested work is routine maintenance vs. “substantial construction” (50% rule). § 25.50.050.
If proposing changes to a nonconforming structure, demonstrate the alteration does not increase the degree of nonconformity and does not remove more than 50% of the exterior first floor walls unless special permit/designation applies. § 25.54.010.B.2.
If structure has been destroyed, obtain a licensed appraiser’s market‑value determination to see whether the 50% rebuild limit applies; plan to comply with current zoning if ≥50% destroyed unless a specific exception applies. § 25.54.030.
If change of use is proposed, prepare to justify similarity or apply for a Director authorization; conversion to conforming use is permanent. § 25.56.030.
If parking is nonconforming and the project intensifies or changes use, include a parking plan that meets Chapter 25.40 or show an applicable exception (e.g., BRMU rebuild rules). § 25.58.010 and Chapter 25.40.
Expect design review/possible special permits for major changes; consult design review and variances if standards can’t be met.

Risks & Ambiguities

Issue	Why it matters	What to verify
50% destruction threshold	If damage ≥ 50% of market value, nonconforming structure rights generally expire and rebuilding must meet current zoning (subject to residential exceptions). (§ 25.54.030)	Verify appraised market value, measure against § 25.54.030, and confirm time windows for permits/building activity.
“Degree of nonconformity” increase	Alterations that increase discrepancy (e.g., larger FAR encroachments) will trigger requirement to bring the whole building into compliance. (§ 25.54.010.B)	Confirm calculations for FAR/coverage/height and whether proposed work is “substantial construction.”
Abandonment vs. active marketing	A nonconforming use that is idle for 180 days may lose status; incomplete marketing or building activity has limited protections. (§ 25.56.040.A)	Produce documentation of continuous marketing, business licensing, or construction permits to rebut abandonment.
Conflicts with state ADU law	State ADU law restricts denial for nonconforming zoning unless safety is at issue; local nonconforming rules still apply to structure/destruction. (State law summarized in ADU guidance)	Consult Burlingame planners and review ADU guidance plus § 25.54 nonconforming structure rules. Verify with the jurisdiction.
Director vs. Commission discretion	Many determinations are at the Director level but appeals or revocations go to Commission; outcomes can vary. (§ 25.50.040, § 25.50.060)	Confirm required submittal package and appeal timelines in Chapter 25.98 (Appeals) and permit processing chapters.

Plain‑English Summary

If your building, lot, or business was legal when it started but doesn’t meet today’s Burlingame rules, the City generally lets it continue—but you can’t expand it, you must prove it was lawful, and certain triggers (like 180 days of abandonment or destruction ≥50% of value) will terminate the protected status. See the nonconforming rules in § 25.50, § 25.52, § 25.54, § 25.56, and § 25.58 for the precise limits and exceptions.

Source References

Burlingame Zoning Ordinance (Title 25), Article 5 Nonconformities — § 25.50.010 et seq.; downloaded from https://ecode360.com/BU4910. § 25.50.010
Chapter 25.52 Nonconforming Lots — § 25.52.010–.020. § 25.52.010
Chapter 25.54 Nonconforming Structures — § 25.54.010–.050 (including § 25.54.030 destruction rule and § 25.54.040 residential exceptions). § 25.54.030
Chapter 25.56 Nonconforming Uses — § 25.56.010–.050 (continuation, restriction on extension, abandonment). § 25.56.020
Chapter 25.58 Other Nonconforming Provisions (parking, fences, landscaping) — § 25.58.010–.030. § 25.58.010
Burlingame district & development standards: Residential districts (R‑1—R‑4) Chapter 25.10 and Mixed‑Use/DD chapters (CMU, BRMU, RRMU, NBMU) § 25.10, § 25.14, § 25.16 (specific tables referenced above).
California ADU guidance (state interplay with nonconforming zoning) — 2025 California ADU handbook (included in project materials).

Sources

Retrieved passages

Burlingame Zoning Code (§ 25.54.050.) High relevance
Burlingame Zoning Code (§ 25.56.040.) High relevance
Burlingame Zoning Code (Title 25.) High relevance
Burlingame Zoning Code (article shall) High relevance
Burlingame Zoning Code (article with) High relevance
CFC § 25.54.040 (Section 25.88.030) High relevance
Burlingame Zoning Code (§ 25.54.020.) High relevance
CBC § 25.50.040 (title or) High relevance
Burlingame Zoning Code (Article 5) Medium relevance
Burlingame Zoning Code (§ 66314) Medium relevance
Burlingame Zoning Code (§ 66333) Medium relevance
Burlingame Zoning Code (§ 25.12.080.) Medium relevance
Burlingame Zoning Code (§ 25.14.030) Medium relevance
CBC § 66321 (§ 66321) Medium relevance
CBC § 66314 (§ 66314) Medium relevance
Burlingame Zoning Code (Section 25.48.200) Medium relevance

Cited sections

Official Burlingame code library

Frequently asked questions

What counts as a legal nonconforming use in Burlingame?

A legal nonconforming use is a use, structure, or lot that was lawfully established before a change in the Zoning Code or map and that now fails to meet current district standards; the Code’s general nonconformity rules apply (Article 5). See § 25.50.030 for establishment and § 25.56.010 for continuation of nonconforming uses.

Can I expand a nonconforming business in Burlingame?

Generally no — a nonconforming use may not be extended beyond its existing scope within the structure or site. Minor repairs/alterations are permitted if they do not increase the degree of nonconformity or the intensity of the operation; see § 25.56.020.

If my building is damaged, when do I lose nonconforming rights?

If a nonconforming structure is damaged or destroyed to the extent of 50% or more of its current market value (per an appraiser), it can only be rebuilt in compliance with current zoning, except for specified residential exceptions. See § 25.54.030 and § 25.54.040.

How long can a nonconforming lot continue to be used?

A lawfully created lot that is nonconforming for area, frontage, width, or access may continue indefinitely and be used as if conforming, but you cannot modify it in a way that increases the degree of nonconformity. See § 25.52.010–.020.

What proof does Burlingame require to confirm a nonconforming status?

The property owner must provide sufficient written evidence to the Director to establish legal nonconforming status; the Director’s determination is appealable to the Commission. See § 25.50.040.

Does nonconforming parking have special rules?

Yes. Nonconforming parking improvements may continue indefinitely, but additional parking is required when a use changes or intensifies; there is a narrow BRMU exception for total destruction where replacement parking is not required if preexisting parking is provided. See § 25.58.010 and Chapter 25.40 for parking standards.

If I convert a nonconforming use to a conforming use, can I later return to the old use?

No. If a nonconforming building or land is changed to a conforming use, the property may not thereafter be used for any nonconforming use — conversion to conforming is permanent. See § 25.56.030.B.

Will the City allow a similar nonconforming use to replace an existing one?

The Director may authorize a change from one legally established nonconforming use to another similar nonconforming use if it is comparable in character and won’t adversely affect surrounding uses; see § 25.56.030.A.

Do special historic designations change how nonconformities are handled?

Yes — designated historic structures get additional relief from the nonconforming alteration limits (for example, a special permit may allow removal of more than 50% of exterior walls where the primary façade and contributing features are preserved). See § 25.54.010.B.2.e and the Special Permit chapter for process.

When can the Commission revoke nonconforming rights?

The Commission may revoke the right to continue a nonconforming use or structure if facts show it will negatively affect its surroundings; revocation procedures follow notice/hearing rules in the Code. See § 25.50.060. ---

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