San Marino — Zoning

Last reviewed: July 2, 2026

Overview

San Marino’s zoning is codified in the Zoning Code (Chapter XXIII) and divides the city into specific zones and area districts (for the single‑family R-1 zone) that control permitted uses, lot sizes, setbacks, height, lot coverage and other development controls. The ordinance adopts an official zone map and a yard (setback) map; rules for reading map boundaries and resolving boundary uncertainty are in the code. Key residential and mixed‑use rules (including by‑right provisions and density bonus implementation) were recently updated; always verify parcel‑specific rules with the City. § 23.01.05, § 23.01.07, § 23.01.08 .

How to read this page and next steps

• If you need the official parcel zoning, consult the City’s zone map and the City staff (the ordinance adopts and references the zone and yard maps). Verify with the jurisdiction for parcel‑level interpretation. § 23.01.07 .
• This page sticks to zoning rules in the San Marino Zoning Code (Chapter XXIII). For site design details consult the San Marino Development Standards and for parking requirements see San Marino Parking. Mention of design review appears where relevant; see San Marino Design Review. I also reference state codes when the local code implements them (e.g., density bonus, ADU law).

Districts — district-by-district breakdown

Note: the ordinance establishes the list of zones and the R‑1 area districts in § 23.01.05; use the official zone and yard maps to find which zone/area district applies to a parcel. § 23.01.05 .

R-1 (Single-Family Dwelling Zone)

• Purpose: preserve single‑family character and regulate lot size, setbacks, coverage and building bulk through area districts. § 23.02.01, § 23.01.03 .
• Typical permitted uses: one single‑family dwelling (except when ADUs are approved), accessory buildings, accessory dwelling units (subject to § 23.02.25), limited home occupations, small licensed care facilities (≤6), and standard incidental residential uses. Commercial uses are prohibited (except limited special events with a CUP). § 23.02.01 .
• Key dimensional standards: R‑1 is divided into area districts IE, I, II, III, IV, V, VI, VII with statutory minimum parcel areas and different setback/height rules. The ordinance spells out the table of minimum building site (statutory parcel area), maximum building height, minimum lot width and minimum street frontage, and minimum front/side/rear yard dimensions for each area district (for example, Area District VI = 10,000 sq ft statutory area; front setback 25 ft; side 5 ft; rear 25 ft; max height 30 ft). See the R‑1 table and related rules in § 23.02.09 and the lot‑coverage/livable‑area limits in § 23.02.10. § 23.02.09, § 23.02.10 .
  • Lot coverage / livable area: maximum gross lot coverage and maximum livable area are set by area district (e.g., Area Districts IE–IV typically capped at 30% of actual lot area; V–VII allow 40% on small lots subject to statutory rules), with rules that allow an increase for large lots and special allowances for corner lots subject to CUP. § 23.02.10, § 23.02.11, § 23.02.12 .
  • Encroachment and structural envelope: the code uses a 30° structural encroachment line and other encroachment limits before a CUP is allowed. § 23.02.13 .
• Front‑yard impervious limits and landscaping: front‑yard impervious coverage is limited (e.g., no more than 45% of the front yard may be impervious) and front landscaping is required; more than 25% impervious in front yard triggers design review. § 23.02.10, § 23.02.18, § 23.02.17 .
• Where it applies: entire single‑family residential neighborhoods are R‑1, further refined by the official yard map/area district assignment. § 23.01.05, § 23.01.07 .

C-1 (Commercial Zone)

• Purpose: allow neighborhood commercial and service uses compatible with the City’s scale while limiting objectionable uses. § 23.03.01 .
• Typical permitted uses: small markets, professional offices, tutorial services, small restaurants (subject to restaurant standards), certain professional and community services; specific exclusions are listed (e.g., heavy manufacturing, motels, major bars). The code lists permitted, conditional and prohibited uses in the C‑1 article. § 23.03.01, § 23.03.10 .
• Key dimensional standards: building height in C‑1 is 30 ft maximum (wireless facilities measured separately) and site area / setback rules are in the C‑1 standards. § 23.03.02 .
• Where it applies: C‑1 applies to San Marino’s retail/commercial nodes per the zone map. Use the official zone map to confirm. § 23.01.07 .

P&R (Park & Recreational Zone)

• Purpose and uses: public parks, recreational facilities and city‑owned recreation uses; rules reference public‑use compatibility and may allow City recreation uses in residential zones by exception. The P&R article sets standards for permitted park uses. § 23.01.05, other P&R subsections (map) .
• Dimensional standards and where: see the P&R article and zone map for parcel‑level rules; verify with City staff.

H&C (Historical & Cultural Zone)

• Purpose: accommodate multi‑family and institutional uses in historically/culturally designated areas with specific design/site standards for context‑sensitive infill. § 23.05.03 .
• Typical permitted uses: multi‑family residential subject to objective design standards; the article establishes density and design rules specific to H&C parcels. § 23.05.03.04 .
• Key dimensional standards (examples): maximum density 30 dwelling units/acre, maximum height 36 ft and up to 3 stories, and maximum lot coverage 60% for multi‑family projects in the H&C zone. § 23.05.03.04–.07 .
• Where it applies: designated historic/cultural districts and sites on the zone map; consult the H&C article and the Historic Preservation rules. See also San Marino Historic Preservation.

RM1 (Multi‑Family Residential Zone)

• Purpose: regulate multi‑family housing types, set permitted uses and objective development standards intended to produce high‑quality multi‑family design. § 23.20.02, § 23.20.03 .
• Typical permitted uses: accessory residential uses, multi‑family units, residential care facilities, ADUs, employee housing under certain rules, emergency shelters and transitional/supportive housing subject to objective standards. The RM1 use table shows P/CUP/− designations. § 23.20.02 .
• Key standards: Article 23.20 sets objective development standards, site design, and other controls for multi‑family projects (height, setbacks, parking reductions and objective design review items). § 23.20.03 .
• Where it applies: multi‑family parcels identified on the zone map. For by‑right housing rules see Article 23.23. § 23.23.03–.05 .

RIH (Religious Institution Housing Zone)

• Purpose: regulate housing associated with religious institutions; special use table governs permissible residential care and housing for institutions. § 23.20.02 .
• Typical uses: residential units tied to institutional function, residential care facilities; uses shown in the RM1/RIH use table. § 23.20.02 .
• Standards and where: follow the RM1 table rules and the RIH subsections; check the zone map for locations.

MU‑1 and MU‑2 (Mixed‑Use Zones)

• Purpose: allow mixed residential + commercial or higher intensity residential uses with objective standards that facilitate housing while preserving commercial viability. The MU rules explicitly incorporate State density bonus law and housing objectives. § 23.01.05, § 23.22.01 .
• Typical permitted uses: up to 100% residential allowed in MU zones (subject to minimum residential area/percentage rules); the City added explicit by‑right allowances when a percentage of units are affordable. Recent amendments permit owner‑occupied and rental multi‑family with at least 20% affordable, minimum site/unit counts and minimum density thresholds (e.g., minimum 16 units per site, 20 units/acre and at least 50% of floor area residential in an MU zone in certain circumstances). See the MU terms and the City’s density bonus article. § 23.22.01, MU subsections (ordinance O-24-1415) .
• Key dimensional standards: MU zones have their own objective site and building standards (setbacks, height and lot coverage) in the MU articles and the multi‑family standards article. § 23.20.03, MU articles .
• Where it applies: parcels shown MU on the zone map; consult parcel zoning and the MU subsections for exact requirements.

Quick standards summary (decision‑relevant table)

(For full numeric tables—R‑1 area districts, lot coverage and basements—see § 23.02.09, § 23.02.10, § 23.02.19.)

Practical guidance & comparisons (plain English with ordinance grounding)

• If your property is in R‑1, the first place to check is the area district assigned on the yard map: the minimum parcel size, front/side/rear setback and the maximum allowed livable area/lot coverage all depend on that area district (e.g., Area District VI vs IV). See § 23.02.09 and § 23.02.10.
• Replacing or expanding existing homes: the code caps how much you can increase livable area before the project must conform fully (replacement >50% of replacement value triggers full conformance) — see § 23.02.22. That commonly forces full compliance with setback and coverage rules for larger rebuilds.
• Want to add an ADU? ADU rules are referenced in the R‑1 uses and elsewhere; local ADU rules must comply with state ADU law. See the R‑1 ADU allowance § 23.02.01 and cross‑check with San Marino ADUs and California ADU law. § 23.02.01
• For multi‑family or mixed‑use housing projects, the City has objective design standards and a by‑right stream for certain affordable developments and density bonus implementation aligned with state law — see § 23.20.03, § 23.22.01, and the by‑right Article 23.23 for eligibility rules. § 23.20.03, § 23.22.01, § 23.23.03–.05 .
• If you need a less‑than‑standard setback or other deviation, the code provides for variances, conditional use permits, and minor exceptions; note that findings for CUPs/variances are not automatic and some decisions cannot override other code provisions. See Article 07 (variances/CUPs) and Article 09 (minor exceptions). § 23.07.10 .

Inline resources used by applicants: consult San Marino Land Use, San Marino Development Standards, San Marino Design Review, and the state’s California Building Standards Code where the zoning code references building standards (e.g., in hazard or habitable space rules).

Checklist (what an applicant must satisfy for a typical R‑1 addition / new home)

• Confirm parcel zone and R‑1 area district on the City zone/yard maps. § 23.01.07
• Verify maximum lot coverage and maximum livable area for your area district. § 23.02.10
• Check minimum front/side/rear setbacks and maximum height for your area district. § 23.02.09
• Confirm impervious surface limits in the front yard and whether design review is triggered (>25% impervious). § 23.02.11, § 23.02.10
• If the project increases lot coverage / livable area above limits, prepare for a variance or conditional use permit (per code standards and findings). § 23.07.02, § 23.02.20
• Check parking requirement references and whether parking reductions are available (see San Marino Parking and § 23.10.03). § 23.10.03
• For projects triggering design review, follow the San Marino Design Review process and objective standards. § 23.15.03
• If the site is in H&C or subject to overlays/historic rules, prepare design materials consistent with H&C standards and San Marino Historic Preservation. § 23.05.03

Risks & Ambiguities

Plain-English Summary

San Marino’s zoning code (Chapter XXIII) divides the city into named zones — notably R‑1 (single‑family, with area districts IE–VII), C‑1, RM1, H&C, and MU zones — each with explicit permitted uses, setbacks, height limits and lot‑coverage rules. R‑1 rules are highly prescriptive by area district (look up your yard map), multi‑family and mixed‑use zones have objective standards and some by‑right housing paths for qualifying affordable projects, and any uncertainty about map lines, nonconforming features or variances requires verification with City planning staff. § 23.01.05, § 23.02.09–.11, § 23.20.02, § 23.05.03, § 23.23.03–.05

Source References

• Zoning Code—Zones list; yard/zone map adoption and boundary rules: § 23.01.05, § 23.01.07, § 23.01.08.
• R‑1 Single‑Family Dwelling Zone uses, area district table, setbacks, lot coverage and related rules: § 23.02.01, § 23.02.09, § 23.02.10, § 23.02.11, § 23.02.13, § 23.02.22.
• C‑1 uses and standards including maximum height: § 23.03.01, § 23.03.02, § 23.03.03.
• Multi‑family zone uses and standards (RM1, RIH, MU articles and development standards): § 23.20.02, § 23.20.03, § 23.22.01, § 23.23.03–.05.
• H&C zone multi‑family density, height and lot coverage: § 23.05.03.04–.07.
• By‑right approvals and density bonus implementation: Article 23.22 and 23.23 (density bonus and by‑right procedures). § 23.22.01, § 23.23.02–.05.
• Nonconforming uses and repair/rebuild limits: Article 23.06 (e.g., § 23.06.10, § 23.06.11).
• Parking cross‑references (used for restaurants and other uses): § 23.10.03 (see the Parking article and San Marino Parking).

(These citations are to the supplied San Marino Zoning Code material used to prepare this page.)

Retrieved passages

• San Marino Zoning Code (ARTICLE 22) High relevance show source text
• San Marino Zoning Code (ARTICLE 23) High relevance show source text
• San Marino Zoning Code (chapter of) High relevance show source text
• San Marino Zoning Code (chapter pertaining) High relevance show source text
• San Marino Zoning Code (article 07) High relevance show source text
• San Marino Zoning Code (Section 65943.) High relevance show source text
• San Marino Zoning Code (chapter of) High relevance show source text
• San Marino Zoning Code (chapter shall) High relevance show source text
• San Marino Zoning Code High relevance show source text
• San Marino Zoning Code (Section are) High relevance show source text
• San Marino Zoning Code (chapter without) High relevance show source text
• San Marino Zoning Code (section shall) High relevance show source text
• San Marino Zoning Code (chapter shall) High relevance show source text

Cited sections

• Zoning Code—Zones list; yard/zone map adoption and boundary rules: **§ 23.01.05**, **§ 23.01.07**, **§ 23.01.08**. (§ 23.01.05)
• R‑1 Single‑Family Dwelling Zone uses, area district table, setbacks, lot coverage and related rules: **§ 23.02.01**, **§ 23.02.09**, **§ 23.02.10**, **§ 23.02.11**, **§ 23.02.13**, **§ 23.02.22**. (§ 23.02.01)
• C‑1 uses and standards including maximum height: **§ 23.03.01**, **§ 23.03.02**, **§ 23.03.03**. (§ 23.03.01)
• Multi‑family zone uses and standards (RM1, RIH, MU articles and development standards): **§ 23.20.02**, **§ 23.20.03**, **§ 23.22.01**, **§ 23.23.03–.05**. (§ 23.20.02)
• H&C zone multi‑family density, height and lot coverage: **§ 23.05.03.04–.07**. (§ 23.05.03.04)
• By‑right approvals and density bonus implementation: Article **23.22** and **23.23** (density bonus and by‑right procedures). **§ 23.22.01**, **§ 23.23.02–.05**. (§ 23.22.01)
• Nonconforming uses and repair/rebuild limits: Article **23.06** (e.g., **§ 23.06.10**, **§ 23.06.11**). (§ 23.06.10)
• Parking cross‑references (used for restaurants and other uses): **§ 23.10.03** (see the Parking article and San Marino Parking). (§ 23.10.03)
• SanMarino_ZoningCode.md

• Official San Marino code library