Local zoning · San Marino

San Marino — Development Standards

Q: What can I build on an R‑1 lot in San Marino?

In the R‑1 zone you may build a single‑family residence and customary accessory buildings; accessory dwelling units are allowed subject to § 23.02.25 ADU rules. Commercial uses are generally prohibited in R‑1. See the permitted use list for R‑1 in § 23.02.01 .

Q: What are San Marino setback requirements for a single‑family lot?

Setbacks are tied to the property’s mapped Area District . The R‑1 table in § 23.02.09 lists minimum front/side/rear yard dimensions by area district (for example front yards range roughly 25–40 ft depending on district). Always check the yard map as it can specify larger dimensions.

Q: What is the maximum height I can build in R‑1 and C‑1?

R‑1 maximum height depends on area district (typically 30–35 ft per § 23.02.09 ). The C‑1 building height limit is 30 ft. under § 23.03.02 . For H&C and mixed‑use zones consult the zone‑specific articles (H&C 36 ft. for multi‑family; MU heights are in Table 2).

Development Standards under the San Marino local zoning and planning code, with the controlling citations.

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Last reviewed: July 2, 2026

Overview

This page summarizes the San Marino municipal zoning development standards that control setbacks, height, lot coverage, density, and related dimensional controls found in Chapter XXIII of the San Marino Municipal Code. It is grounded in the City's zoning text (Chapter XXIII) and cites the controlling sections; use this as a planning reference but Verify with the jurisdiction for parcel-specific application and map-derived yard lines. For context on the zoning map and zone definitions see San Marino Zoning.

District-by-district breakdown (purpose, typical uses, key dimensional standards, where it applies)

Note: where a district uses multiple area-districts (R‑1), the table and text below show the City’s statutory parameters published in the Code. Always confirm the property’s mapped area district on the City's yard/zone maps (Verify with the jurisdiction).

R‑1 (Single‑Family Dwelling Zone)

Purpose & typical uses: Primarily single‑family residential; accessory residential structures and accessory dwelling units (subject to ADU rules) are allowed; commercial uses are generally prohibited. See § 23.02.01.
Key dimensional standards (by Area District) and where it applies: Minimum building site (statutory parcel area), maximum building height, and required yard dimensions vary by area district and are set in the R‑1 table in § 23.02.09. Examples (selected rows shown in § table):
- Area District IE: Minimum building site 60,000 sq. ft., max height 35 ft., front yard 40 ft.; rear/side as listed in § 23.02.09.
- Area District VII: Minimum building site 9,000 sq. ft., max height 30 ft., front yard 25 ft.; side yard minimum 5 ft..
Lot coverage and livable area limits: The Code caps maximum gross lot coverage and livable area by area district (percent of actual and statutory lot area) in § 23.02.10 (e.g., many area districts have 30–40% lot coverage limits depending on district); increased allowances for larger lots are in § 23.02.11.
Other R‑1 rules: backyard accessory buildings, garage placement, encroachment limitations (30° structural line), numeric bedroom limits (no more than 6 bedrooms without a CUP), and front‑yard development controls (pools, courts) are in §§ 23.02.05–23.02.20.

C‑1 (Commercial Zone)

Purpose & typical uses: Neighborhood and community commercial uses; mixed retail and some residential where allowed by specific provisions. See § 23.03. series.
Key dimensional standards:
- Maximum building height for C‑1: 30 ft. (see § 23.03.02).
- Multi‑family residential development standards within C‑1 are handled by the objective multi‑family standards in § 23.03.10 (density cap 20 du/ac, max height 30 ft., lot coverage 60% for multi‑family projects).
Parking and special operating limits for particular commercial uses (markets, restaurants, etc.) are in the parking tables (see the Parking page and § 23.10 for use‑specific ratios).

H&C (Historical & Cultural Zone)

Purpose & typical uses: Protect and manage historically/culturally sensitive properties and allow multi‑family where appropriate. See Article 05.
Key dimensional standards for multi‑family in H&C:
- Density: 30 du/acre (max) — § 23.05.03.04.
- Height: 36 ft. and no more than 3 stories — § 23.05.03.05.
- Lot coverage: 60% max for multi‑family — § 23.05.03.06.

RM1 (Multi‑Family Residential Zone) and RIH (Religious Institution Housing Zone)

Purpose & typical uses: Multi‑family dwellings, accessory residential uses; RIH allows housing associated with religious institutions. See § 23.20.02 uses table.
Standards: Multi‑family development standards for these zones are set in § 23.20.03 and related subsections; RM1 and RIH projects must meet the objective site/design standards in that article (density caps and objective design terms are included there).

MU‑1 and MU‑2 (Mixed‑Use Zones)

Purpose & typical uses: Combine residential and commercial; require minimum residential density and floor‑area mixes. See § 23.21.03.02–.04.
Key dimensional standards (Table 2 summary in § 23.21.03.03):
- MU‑1: residential density 25–30 du/ac, max height 36 ft.; ground‑floor commercial built‑to line within 5 ft. of right‑of‑way.
- MU‑2: residential density 30–40 du/ac, max height 48 ft.; build‑to lines and transition setbacks specified in Table 2.
FAR for commercial uses in mixed‑use zones: maximum 0.50 for commercial uses in mixed‑use zones per § 23.21.03.02.

P&R (Park & Recreational Zone)

Purpose & typical uses: Public parks and recreational uses; dimensional controls are tailored to public property and not the residential lot standards. See Article 04 and zone definitions.

Short standards table (most decision‑relevant items)

Standard / Topic	Typical Value (San Marino)	Code Reference
R‑1 area‑district min building site (examples)	IE: 60,000 sq ft; VII: 9,000 sq ft	§ 23.02.09
R‑1 max building height	30–35 ft (depends on area district)	§ 23.02.09
Lot coverage / livable area caps	30–40% (percent varies by area district; see table)	§ 23.02.10
R‑1 side yard (typical smaller lots)	5 ft (varies by area district)	§ 23.02.09
R‑1 front yard (typical)	25–40 ft depending on area district	§ 23.02.09
MU‑1 density / height	25–30 du/ac, max 36 ft.	§ 23.21.03.03
MU commercial FAR	0.50 (commercial uses in MU zones)	§ 23.21.03.02
C‑1 multi‑family density/height	20 du/ac, max 30 ft. (multi‑family in C‑1)	§ 23.03.10
ADU side/rear setbacks	4 ft (converted ADU exception: none required)	§ 23.02.25 (ADU rules)

Practical guidance & synthesis (plain‑English interpretation)

Know your mapped area district first. R‑1 numeric limits (height, front/side/rear yards, statutory lot area) are driven by the mapped Area District (IE, I, II … VII) and are mandatory unless altered by a formal variance or conditional use permit (see § 23.02.09 and request/relief rules in § 23.02.20).
Lot coverage is controlled two ways: as a percent of the actual lot area and as a percent of the statutory lot area; the ordinance caps both and requires you to use the smaller of the two calculations (see § 23.02.10). For larger lots there is a 10% incremental allowance described in § 23.02.11.
For multi‑family or mixed‑use projects, the Code provides separate objective development standards (Articles 03, 05, 20, 21) with explicit density, height, and lot‑coverage caps — these may permit taller heights or higher densities than R‑1 but are zone‑specific (e.g., H&C 36 ft./30 du/ac, MU zones per Table 2). Always read the zone‑specific article before assuming R‑1 rules apply.
ADUs: San Marino’s ADU rules align with State ADU law but add local numeric limits (bedrooms, unit sizes, detached/attached height rules and setback exceptions). ADUs can be ministerially approved when they meet the ADU development standards in § 23.02.25 (setbacks 4 ft for side/rear in most cases; detached ADU height allowances up to 18–20 ft in qualifying locations). See the ADU page for the local ADU process.
Design review: many additions, new residences, or projects that do not meet objective standards will require design review — documentation checklists and timelines are in the design review article (Article 15, e.g., § 23.15.13 for submittal requirements). See the Design Review page.
Parking: use‑specific parking ratios are in the parking article/tables (Article 10). Certain mixed‑use and density‑bonus situations allow parking reductions consistent with state law. See the Parking page and § 23.10 tables.

Links to related local topics (first natural mention only): San Marino Zoning, San Marino Parking, San Marino Design Review, San Marino Overlay Districts, San Marino Historic Preservation, San Marino Variances and Exceptions, San Marino ADUs, California Building Standards Code.

Checklist (applicant must satisfy)

Confirm mapped zone and mapped Area District (IE–VII) and yard map lines; apply corresponding R‑1 table values if in R‑1 § 23.02.09.
Verify statutory lot area vs actual lot area to calculate lot coverage / livable area caps per § 23.02.10–.11.
Check height limit for the applicable zone (e.g., R‑1 area district, C‑1 § 23.03.02, H&C § 23.05.03.05, MU table).
Determine whether the proposal complies with accessory building and garage setback and coverage rules (§ 23.02.09 and accessory subsections).
For ADUs: confirm unit type, size limits, setbacks, and whether the ADU is exempt from Planning ADU Application; complete ministerial ADU review per § 23.02.25.
Prepare design‑review documentation if project alters square footage or fails to meet objective standards (§ 23.15.13).
Verify parking requirements for the proposed use and whether a density bonus / parking reduction applies (Article 22 & Article 10).
If requesting deviations, prepare variance/CUP evidence per Article 07 and the variance/exception standards. See Variances and Exceptions page.

Risks & Ambiguities

Issue	Why it matters	What to verify
Which Area District applies	R‑1 setbacks, height, and minimum lot area are driven by area district mapping	Verify parcel’s area district on the zone/yard map and confirm statutory lot area in § 23.02.09.
Lot coverage calculation method	Code requires comparing percent of actual lot vs percent of statutory lot — you must use the smaller value	Confirm actual lot area, statutory lot area, and apply § 23.02.10–.11 math.
ADU setback exceptions and conversion rules	State ADU law + local ADU provisions create exceptions (converted ADUs may have no setbacks)	Review the ADU standards in § 23.02.25 and confirm whether the unit is a conversion or new construction.
Yard map vs numeric table conflicts	Yard map minimums may be larger than table minimums	If yard map shows larger dimension, the yard map controls (see § 23.02.09). Verify with the Planning Division.
Nonconforming existing conditions	Existing nonconformances (e.g., reduced side yard) affect what additions can be ministerial	Check nonconforming rules and whether conditional use/variance is required per § 23.02.04–.20; existing nonconforming side yards may permit limited single‑story additions under conditions.
Encroachment (30° structural line)	Adds a vertical/bulk test that may limit additions even if setback/height meet numbers	Confirm encroachment envelope and whether a CUP is required per § 23.02.13.

Plain‑English Summary

If your property is in an R‑1 zone the City’s yard map and the R‑1 area‑district table set your minimum lot size, front/side/rear setbacks, and maximum height; lot coverage is limited by percent rules and special encroachment and accessory building rules may further restrict additions. For multi‑family, mixed‑use, C‑1 and H&C zones separate, zone‑specific objective standards control density, height, lot coverage and FAR. ADUs have a ministerial pathway but must meet the numerical ADU standards in the Code. Always confirm the mapped area district and yard map lines with the Planning Division.

Source References

San Marino Zoning Code — Chapter XXIII (general definitions and zones): § 23.01.01 – § 23.01.07.
R‑1 zone: Lot area, height, setbacks table — § 23.02.09.
Lot coverage & livable area limits — § 23.02.10–23.02.12.
R‑1 accessory development, garages, and parking rules — § 23.02.05–23.02.20.
Encroachment (30° structural line) and bedroom/story limits — § 23.02.13–23.02.15.
C‑1 multi‑family standards (density, height, lot coverage) — § 23.03.10 and building height § 23.03.02.
H&C multi‑family standards: density, height, lot coverage — § 23.05.03.04–.06.
RM1 / RIH uses table and multi‑family standards — § 23.20.02–23.20.03.
Mixed‑use (MU‑1, MU‑2) standards and Table 2 (densities, heights, FAR) — § 23.21.03.02–.04.
ADU/JADU development standards, process and ministerial review — § 23.02.25 (ADU article and definitions in § 23.01.01).
Design Review submittal requirements — § 23.15.13.

If you need parcel‑specific checks (yard map reading, statutory lot area, mapped overlays, or recorded easements), Verify with the City of San Marino Community Development / Planning Division.

Sources

Retrieved passages

San Marino Zoning Code High relevance
San Marino Zoning Code (Chapter XXIII) High relevance
San Marino Zoning Code (section shall) High relevance
San Marino Zoning Code (section establishes) High relevance
San Marino Zoning Code (chapter without) High relevance
San Marino Zoning Code (section establishes) High relevance
San Marino Zoning Code (Section are) High relevance
CFC § 200 (title is) High relevance
San Marino Zoning Code (section shall) High relevance
San Marino Zoning Code High relevance
CBC § 096 (section shall) High relevance
San Marino Zoning Code High relevance
CBC § 66314 (§ 66314) High relevance
San Marino Zoning Code (Section 21064.3) Medium relevance
San Marino Zoning Code (Section 66323.) Medium relevance
San Marino Zoning Code (chapter XI) Medium relevance
San Marino Zoning Code (§20.4) Medium relevance
CBC § 66321 (§ 66321) Medium relevance
CBC § 66321 (§ 66321) Medium relevance
CBC § 66321 (section 66321) Medium relevance
San Marino Zoning Code (article 07) Medium relevance

Cited sections

Official San Marino code library

Frequently asked questions

What can I build on an R‑1 lot in San Marino?

In the R‑1 zone you may build a single‑family residence and customary accessory buildings; accessory dwelling units are allowed subject to § 23.02.25 ADU rules. Commercial uses are generally prohibited in R‑1. See the permitted use list for R‑1 in § 23.02.01.

What are San Marino setback requirements for a single‑family lot?

Setbacks are tied to the property’s mapped Area District. The R‑1 table in § 23.02.09 lists minimum front/side/rear yard dimensions by area district (for example front yards range roughly 25–40 ft depending on district). Always check the yard map as it can specify larger dimensions.

How much lot coverage am I allowed?

Lot coverage and maximum livable area are limited by a percentage test in § 23.02.10 (percent of actual lot area and percent of statutory lot area — use the smaller). Some districts typically use 30–40% figures; § 23.02.11 allows a 10% increase for larger lots.

What is the maximum height I can build in R‑1 and C‑1?

R‑1 maximum height depends on area district (typically 30–35 ft per § 23.02.09). The C‑1 building height limit is 30 ft. under § 23.03.02. For H&C and mixed‑use zones consult the zone‑specific articles (H&C 36 ft. for multi‑family; MU heights are in Table 2).

Do I need design review for an addition or new home?

If your proposal alters square footage or fails objective standards you may trigger design review. The design review documentation and effective decision timelines are set out in Article 15 (see § 23.15.13 for required submittal materials). Projects that meet objective, ministerial standards may be approved without discretionary design review per the relevant objective standards article.

Can I build an ADU on my lot, and what setbacks apply?

ADUs are allowed on lots zoned for single‑family or multi‑family uses and are governed by the ADU article (§ 23.02.25). Converted ADUs within existing structures generally require no additional setbacks; new attached/detached ADUs typically require 4‑ft side/rear setbacks unless a specific exception applies. San Marino’s ADU provisions set unit size, bedroom, and height rules as well as ministerial timelines.

How is floor‑area ratio (FAR) treated in mixed‑use zones?

The Code sets zone‑specific FAR limits for certain uses; for example the maximum FAR for commercial uses in mixed‑use zones is 0.50 per § 23.21.03.02, and mixed‑use development standards (density, height, build‑to lines) are in Table 2 (§ 23.21.03.03).

If my lot is nonconforming (smaller setback), can I add a second story?

Limited additions may be possible but specific rules apply. The Code allows some single‑story additions where an existing legal nonconforming side yard exists, but additions below certain thresholds or larger changes will need a conditional use permit or variance per the nonconforming and relief rules (see § 23.02.09 and request/relief provisions). Verify with the Planning Division.

Where do I find parking requirements for my proposed use?

Parking ratios for specific uses are in Article 10 (parking tables) and some corridors have modified requirements; special parking reductions can apply with density bonuses and under state housing laws. Refer to the Parking page and the Code’s parking tables (see Article 10).

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