Local zoning · La Mirada

La Mirada — Historic Preservation

Historic Preservation under the La Mirada local zoning and planning code, with the controlling citations.

Last reviewed: July 2, 2026

Overview

La Mirada’s zoning ordinance treats historic preservation through definitions, targeted development limits, and regulatory procedures scattered across the Title (most importantly the flood-hazard/variance rules, ADU rules, site-plan/design-review criteria, and project-specific chapters). Key protections are (1) a formal definition of “historic structure” that triggers special treatment, (2) a narrow variance allowance to preserve historic character in constrained situations, and (3) multiple program-level prohibitions on demolition or ministerial approvals in places that are designated historic. See the controlling local code passages below for specifics. § 21.32.030 defines historic structures; variances and limited exceptions appear at § 21.32.220 and the accessory-dwelling unit rules that affect historic properties are in § 21.54.020 and related ADU rules.

What the ordinance actually says (deep synthesis)

Definition: A “historic structure” is defined using the federal/state/local register tests (National Register, contributing to a registered district, state inventory, or a local inventory) at § 21.32.030. This definition is the gatekeeper for most special rules.
Flood/variance exception for preservation: In the flood-hazard chapter, the planning commission may grant variances to permit repair/rehabilitation of historic structures only if the work “will not preclude the structure’s continued designation as an historic structure” and the variance is “the minimum necessary to preserve the historic character and design.” See § 21.32.220 (variance conditions) and related variance procedures in § 21.32.210–230.
ADUs and historic property rules: Accessory Dwelling Units (ADUs) are regulated in Chapter 21.54. The city generally allows ADUs by-right subject to objective standards, but the ordinance treats historic properties specially:
- ADUs cannot be located on a lot adjacent to a property listed on the California Register of Historical Places in the ministerial ADU streamlined approvals (see § 21.54.020(3)).
- The ADU rules also recognize historic districts in practical exemptions (for example, ADUs wholly inside an “architecturally and historically significant historic district” may qualify for parking exemptions) — see the ADU parking and exemption clauses at § 21.54.020 (parking/exemptions) and related ADU subsections.
- If an ADU is proposed on a lot listed on the California Register, it must “conform with all federal, state, and local guidelines.” (ADU-specific language appears in the ADU chapters; see § 21.54 and cross references.)
Demolition / large-project limits: Some project-specific chapters prohibit demolition of historic structures as an eligibility or siting requirement (for example, the higher-education / faith-based housing chapter prohibits demolition of structures listed on national, state, or local historic registers — § 21.53.030(5)).
Design / site-plan review: The site plan / design-review criteria call for harmony with “past development” and consideration of building form and materials; those standards are used to evaluate compatibility with the surrounding character when reviewing changes (Site Plan Review criteria in § 21.114.050). This is the primary discretionary tool to control changes that could affect historic character when an application is discretionary.
Where “historic” matters in ministerial streams: The code explicitly excludes properties in a Designated Historic District or listed on the State Historic Resource Inventory from some ministerial pathways (for example, Primary/Secondary Unit ministerial process at § 21.18.070 disqualifies sites in designated historic districts).

Notes on how the pieces fit together: the local ordinance does not centralize historic-preservation rules into a single chapter; instead, the definition and several targeted rules (variance exceptions, ADU limits/exemptions, demolition limits for certain projects, and references inside site-plan and discretionary review sections) form the operational preservation regime. The common thread is: designation (national/state/local) triggers limits and extra protections; when work is allowed, it must not preclude continued designation and must follow applicable federal/state/local preservation guidelines.

District-by-district breakdown (where preservation rules appear)

Note: the code uses mapped base zones and overlay zones; below I list the La Mirada zones or overlays that the ordinance explicitly references in connection with historic resources, what the ordinance says about purpose/where it applies, and the preservation-relevant rules found in the code. All citations point to the specific sections that reference “historic,” historic districts, or historic-structure treatment.

R-1 (Single‑Family Residential)

Purpose / where it applies: La Mirada’s single-family zones are the R-1 family of zones (examples enumerated in the code are R-1-6,000, R-1-7,500, R-1-8,000, R-1-10,000, R-1-15,000). These are the city’s single-family residential zones used in ministerial housing pathways. § 21.18.070 lists R‑1 as the single-family zone for ministerial two-unit rules.
Typical permitted uses: single-family dwellings (plus accessory uses per the Title). See the R‑1 listing at § 21.18.070.
Preservation-relevant rules:
- Properties in a Designated Historic District or on the State Historic Resource Inventory are explicitly excluded from the ministerial Primary/Secondary Unit pathway (so owners in historic districts cannot use that particular ministerial stream) — § 21.18.070(2)(A).
- ADUs on or adjacent to officially listed historic property are treated specially under the ADU chapter — see § 21.54.020(3).
Key dimensional standards: Not found in retrieved materials for a consolidated R‑1 dimensional table in the excerpts provided. Verify with the jurisdiction or Chapter 21.17/21.18 full text for front/side/rear setback, height and lot coverage values. (Verify with the jurisdiction.)

Special Housing Overlay — SHO

Purpose / where it applies: The Special Housing Overlay (SHO) is a mapped overlay with subareas that set housing densities and development standards; it’s an overlay applied to targeted parcels shown in the zoning map. See the SHO development standards tables in § 21.38.050 et seq.
Typical permitted uses: Residential or mixed‑use projects consistent with the overlay; certain projects receive streamlined processing under overlay rules.
Preservation-relevant rules:
- Large projects under special chapters still may not demolish historic structures on a national, state, or local register: see the higher‑education/faith-based housing development standards that prohibit demolition of historic buildings — § 21.53.030(5) (this is an example of project-specific protection that would apply where SHO development intersects historic properties).
Key dimensional standards: The SHO tables list setbacks, heights, FAR, and densities at § 21.38.050; those tables are development-standard references but do not replace the need to check for historic‑site specific design review.

Flood Hazard Overlay — F (Flood Hazard)

Purpose / where it applies: The F overlay applies to mapped special flood hazard areas; Chapter 21.32 controls development and variances in the overlay. § 21.32.040–050 explain applicability and mapping.
Typical permitted uses: Regulated development with floodplain management standards; many normal uses allowed but subject to elevation, construction, and variance requirements.
Preservation-relevant rules:
- The flood chapter includes the historic-structure definition (§ 21.32.030) and explicitly allows variances for repair/rehabilitation of historic structures when required to preserve historic character, provided the variance is the minimum necessary — see § 21.32.220. This is the principal place where the code allows a deviation from flood elevation or construction standards specifically to preserve historic properties.
Key dimensional/administrative standards: The flood chapter’s construction standards, elevation requirements, and variance procedures are detailed across § 21.32.120–150 (refer to the flood chapter text for technical requirements).

Other zones / project chapters where “historic” appears

Chapter 21.53 (Residential on Higher‑Education or Faith‑Based Properties): prohibits demolition of listed historic structures — § 21.53.030(5). This shows preservation protections can be embedded in project-specific chapters.
Site Plan / Design Review (Chapter 21.114): review criteria require compatibility with “past development” and consider architectural features and materials during site plan review (§ 21.114.050) — the discretionary/design route is the city’s tool to protect character when projects require discretionary approvals.

Quick-reference table — decision‑relevant rules

Rule / Decision point	What it means in practice	Code reference
Definition of “historic structure”	Triggers special treatment if a property is individually listed or contributes to a register/inventory	§ 21.32.030
Variance for repair/rehab of historic buildings in flood areas	Commission may grant minimum‑necessary variance to preserve historic character	§ 21.32.220
ADU ministerial exclusions for historic sites	ADU ministerial stream excludes ADUs on/adjacent to properties on the California Register; ADUs on California‑registered properties must conform to federal/state/local guidelines	§ 21.54.020(3) and surrounding ADU rules (Chapter 21.54)
ADU parking exemption inside historic districts	ADUs located entirely within architecturally/historically significant historic districts may qualify for parking exemptions	ADU parking/exemption clauses in ADU chapter (see § 21.54 ADU parking subsections)
Discretionary design/site plan criteria to protect character	Site Plan Review standards assess compatibility with “past development,” facade features, materials, and massing (used in discretionary reviews)	§ 21.114.050
Project-specific demolition prohibitions	Some chapters (e.g., higher‑education housing) forbid demolition of historic structures for eligibility	§ 21.53.030(5)

Checklist — what an applicant must satisfy when a property is (or may be) historic

Confirm whether the property is individually listed or contributes to a historic district (use the California Register / local inventory). If listed, note it triggers protections per § 21.32.030.
For ADUs: check Chapter 21.54; if the lot or an adjacent lot is listed on the California Register, prepare to meet federal/state/local preservation guidelines and expect ministerial exclusions — § 21.54.020(3).
If the property is in a flood hazard (F) overlay and work affects a historic structure, prepare a variance justification limited to “minimum necessary” changes to preserve character — § 21.32.220.
If the project is discretionary (site plan review, conditional use, planned development), prepare design documentation showing compatibility with existing historic character to satisfy § 21.114.050 review criteria.
For larger developments or overlay projects, check chapter-specific demolition rules (e.g., § 21.53.030(5)) and be ready to demonstrate alternatives to demolition.
When in doubt about map status or eligibility, request an official interpretation from the Community Development Director (the code allows administrative interpretations and appeals) — see interpretation procedures § 21.12.020–040.

Risks & Ambiguities

Issue	Why it matters	What to verify
Is the property “Designated” vs. “Eligible”?	The code treats listed/designated resources differently; “eligible” vs. formally designated changes the procedural outcome	Verify listing status with the City and the California Register; confirm which registry the code’s reference points to (local vs. state vs. national). § 21.32.030 (definition).
Exact dimensional standards for R‑1 (setbacks, heights)	Many preservation decisions hinge on setbacks/lot coverage (for ADUs and additions) but the snippets did not include consolidated R‑1 dimensions	Verify the full Chapter 21.17/21.18 development standards in the municipal code (not found in the retrieved snippets). Verify with the jurisdiction.
Where the ADU parking exemption applies (what qualifies as an “architecturally and historically significant historic district”)	The exemption removes parking burden — but the code does not, in the excerpts, include a local map or a formal local district definition	Verify local designation criteria and map with City; check whether the district is a local ordinance designation or a state register listing; see ADU rules § 21.54.
Interaction with building-code exemptions (historic building code)	Repair/rehab of historic buildings may have different building-code requirements (state Historical Building Code) but zoning code defers to federal/state/local guidelines	Confirm code-application sequencing with Building Division and consult the California Historical Building Code materials; zoning cites preservation but building-code application must be confirmed. Not found in retrieved materials for sequencing.
Project-specific provisions embedded in special chapters	Some chapters embed preservation protections (e.g., § 21.53.030). Missing other project chapters could contain more preservation rules	Do a parcel-specific check of all applicable chapters and specific plans; Verify with the jurisdiction.

Plain‑English summary

If your La Mirada property is listed on a local, state, or national historic register or sits inside a city-designated historic district, the zoning code treats it differently: you may be excluded from some fast-track ministerial approvals (ADU and two‑unit streams), you can only be altered, demolished, or rebuilt in ways that do not preclude continued historic designation, and in flood zones the planning commission may allow narrowly tailored variances to preserve historic fabric. Key rules live in the flood/variance chapter and the ADU chapter, and design/site-plan review is the city’s tool to enforce compatibility. See § 21.32.030, § 21.32.220, § 21.54.020, and § 21.114.050.

Source References

Definition of “historic structure”: § 21.32.030 (La Mirada Zoning/Flood chapter) —
Variance rules for historic structures in flood areas: § 21.32.220 (variance conditions) —
ADU chapter and ministerial ADU rules (historic‑property provisions): Chapter 21.54; see § 21.54.010 and § 21.54.020(3) —
ADU parking/exemptions and ADU dimensional elements referenced across ADU text (parking exemptions for historic-district ADUs): ADU parking subsection (ADU Chapter) —
Site Plan Review criteria (design compatibility, review factors): § 21.114.050 —
Higher‑education / faith-based housing chapter — demolition prohibition for historic buildings: § 21.53.030(5) —
R‑1 identification for ministerial two‑unit rules: § 21.18.070 —
Code adoption, interpretations, and administrative procedures: Chapters 21.02, 21.12, 21.84 (interpretation, application completeness) —

Inline internal resources you may need while preparing an application (use these pages in your workflow):

La Mirada zoning & planning overview: La Mirada zoning & planning overview
La Mirada Zoning: La Mirada Zoning
La Mirada Land Use: La Mirada Land Use
La Mirada Development Standards: La Mirada Development Standards
La Mirada Parking: La Mirada Parking
La Mirada Design Review: La Mirada Design Review
La Mirada Overlay Districts: La Mirada Overlay Districts
La Mirada ADUs: La Mirada ADUs
California Building Standards Code: California Building Standards Code

(Where the zoning text does not contain precise numbers or mapping in the retrieved excerpts I note “Verify with the jurisdiction.”)

Sources

Retrieved passages

La Mirada Zoning Code (chapter which) Medium relevance
CBC § 51178 (Section 51178.) Medium relevance
La Mirada Zoning Code (Section 21.82.030.) Medium relevance
La Mirada Zoning Code (§ 5) Medium relevance
La Mirada Zoning Code (chapter means) Medium relevance
CBC § 817 (chapter or) Medium relevance
La Mirada Zoning Code (Chapter 21.68) Medium relevance
CBC § 21.17 (section that) Medium relevance
La Mirada Zoning Code (§ 2) Medium relevance
La Mirada Zoning Code (Section 65912.111) Medium relevance
La Mirada Zoning Code (Section 21.32.200) Medium relevance
La Mirada Zoning Code (chapter as) Medium relevance
La Mirada Zoning Code (§ 65915) Medium relevance
La Mirada Zoning Code (§ 66314) Medium relevance
CBC § 5020.1 (Section 5020.1) Medium relevance

Cited sections

Official La Mirada code library

Frequently asked questions

Can I build an ADU on a La Mirada house that’s listed on the California Register?

Yes, but the ADU must conform with applicable federal, state, and local preservation guidelines and the ministerial ADU stream has special exclusions — see the Accessory Dwelling Unit chapter § 21.54.020(3) and surrounding ADU provisions; expect review to ensure the ADU “will not preclude” continued historic designation.

What is the municipal definition of a “historic structure” in La Mirada?

La Mirada defines “historic structure” using register/ inventory criteria (National Register, contributing to a registered district, state inventory, or a local inventory) at § 21.32.030. That definition is the trigger for variance and other special rules.

Can the city allow a variance to avoid modern flood‑elevation requirements for an historic building?

Yes, but narrowly: in the flood-hazard overlay the planning commission may grant a variance to repair/rehab a historic structure only if the alteration will not preclude its continued designation and the variance is the “minimum necessary to preserve the historic character” (see § 21.32.220).

Do ADUs in historic districts need parking in La Mirada?

The ADU chapter includes parking rules and specific exemptions; ADUs located entirely within an “architecturally and historically significant historic district” may qualify for parking exemptions under the ADU parking provisions (see ADU parking/exemptions in Chapter 21.54). Verify district boundaries with the City.

Will design review be required for changes to a historic property?

If the work is discretionary (site plan review, conditional use, or other discretionary approvals), design/site-plan review criteria apply — the city evaluates compatibility with existing character under § 21.114.050. Even ministerial projects on listed properties are subject to preservation constraints in the ADU/other chapters.

Can a large redevelopment project demolish a listed historic building in La Mirada?

Some project chapters and development standards explicitly forbid demolition of historic structures for eligibility (for example § 21.53.030(5) for the higher‑education/faith‑based housing rules). Check the specific chapter that applies to your project; many large projects face demolition prohibitions or tighter review.

Where do I find the “minimum necessary” test if I need a variance to preserve historic character?

The “minimum necessary” standard for variances to historic structures in flood areas is expressed in § 21.32.220; the flood variance chapter (21.32) includes the variance process and findings used by the planning commission.

If my property is in a historic district, can I still use the ministerial Primary/Secondary Unit (SB9‑type) approval?

No — the municipal ministerial provisions for Primary/Secondary dwelling units explicitly exclude properties that are in a designated historic district or on the State Historic Resource Inventory from that ministerial pathway under § 21.18.070(2)(A).

Who interprets whether a resource is historic for zoning purposes?

The Community Development Director issues administrative interpretations and may refer ambiguous matters to the planning commission; check the code’s interpretation procedures (Chapter 21.12). Appeals of interpretations follow the code’s appeal chapters.

If there’s a conflict between preservation rules in different chapters, which controls?

The Title’s conflict rules say the more restrictive provision applies; also project-specific chapters (e.g., specific plans or planned unit developments) may govern where they conflict. See the code’s general conformance/conflict rules in Chapter 21.08 and interpretation rules in 21.12. Verify on a parcel basis.

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