San Dimas — Zoning

Last reviewed: July 2, 2026

Overview

This page summarizes how zoning is organized and enforced under the San Dimas municipal zoning ordinance (the zoning provisions appear in Title 18 of the San Dimas Municipal Code). It explains the official zoning map, the most commonly used base zones and specific-plan districts, the principal overlays, and the key property-development standards you will see when planning a project. Always verify parcel-specific rules with the city — many rules are administered through the official zoning map, specific plans, and overlay designations. (Official zoning-map adoption is governed by § 18.16.020.)

How zoning works in San Dimas (key rules)

• The city adopts an official zoning map and land must be used consistent with the map and the zoning title (§ 18.16.020) .
• Where property is not mapped, it is treated as if zoned the same as the property on the opposite side of the street (§ 18.16.020).
• Many areas are regulated by specific plans (for example the Downtown Specific Plan) that establish their own zoning sub-areas and standards; where the specific plan is silent the Municipal Code applies (§ 18.50.040) .
• Overlays (Affordable Housing Overlay AHO, Development Standards Overlay DS, Scenic Highway Overlay SHO, RPD, etc.) modify or add standards to the underlying base zone; overlay labels are appended to the base zone on the official map (for example C-H (AHO-1) or C-H (SHO)) (§ 18.40.020, § 18.26.020, § 18.108.030) .
• Many project approvals require a development plan and/or design-review application (see Chapter 18.12 for the design-review process) — the code frequently requires development-plan approval before any building is erected in a zone (§ 18.42.060, cross-references to Chapter 18.12) .

Note: This page is strictly about zoning and zoning rules in the municipal code (Title 18). For parking rules see the city’s parking page; for construction rules see the California Building Standards Code. Link references used below: development standards, parking, design review, overlay districts, ADUs, historic preservation.

District-by-district breakdown (selected, San Dimas-specific)

Below are the most decision-relevant base zones and plan districts that appear in the San Dimas zoning code. Each subsection gives the purpose, typical permitted uses, the key dimensional standards you will need for entitlement/feasibility checks, and where the zone applies (when the code gives geography).

SF-A (Single‑Family Agriculture) — SF‑A

• Purpose: To allow urban single‑family homes while permitting certain small-scale agricultural/domestic-animal uses (§ 18.28.010) .
• Typical permitted uses: Any use permitted in the S‑F (single‑family) zone plus limited wholesale nursery/orchard uses and specified animal keeping on parcels 11,000 sq ft+ (§ 18.28.020) .
• Key standards: animal-keeping limits and distance-to-residence rules are specified in § 18.28.020; garage/parking and other development standards are required and utility services must be underground (§ 18.28.020, cross‑refs).
• Where it applies: See official zoning map; the code describes the zone purpose and permitted uses but the map shows parcels designated SF‑A (official map adoption § 18.16.020) .

S-F / SF-7500 (Single‑Family conventional lot standards) — S‑F / SF‑7500

• Purpose: Standard single‑family residential district (treated through Chapter(s) for single-family standards). See the SF-specific development standards chapter for setbacks, lot coverage and accessory rules (§ 18.24 entries and related sections).
• Typical permitted uses: One dwelling unit per lot; usual single-family accessory uses, home occupations, household pets (see Chapter 18.20).
• Key standards (examples that appear in the code text): front yard setback commonly 20 ft (straight-in driveway) or 15 ft (swing-in driveway) for some SF-lots (§ 18.24.050); maximum lot coverage references in the single-family chapters (typical 35% in several single-family contexts, see § 18.24 series) .
• Where it applies: Mapped as S‑F or numeric SF districts on the official zoning map; consult the map at the planning office or the city’s zoning map file (§ 18.16.020) .

MF (Multiple‑Family) — MF

• Purpose: For medium‑ and high‑density multi‑family housing and to ensure compatibility with surrounding uses (§ 18.42.010) .
• Typical permitted uses: Apartments, condominiums, townhomes, senior housing; single-family is allowed in certain MF locations when the lot meets SF‑7500 standards (§ 18.42.020) .
• Key standards:
  • Height: generally 30 ft / two stories (with conditional exceptions allowing up to 35 ft/3 stories under findings) (§ 18.42.050).
  • Ground coverage: maximum 60% (§ 18.42.050 B)
  • Front yard: 20 ft typical; side and rear yards vary by adjacency to single‑family zones (§ 18.42.050 D)
• Where it applies: Mapped as MF with a number for density in some cases (e.g., MF (14)) — density notation appears on the official zoning map (§ 18.42.040) .

MF‑30 (Multiple‑Family 30 units/acre) — MF‑30

• Purpose: Specifically meant to accommodate higher-density multiple‑family developments and to help implement housing element density goals (§ 18.44.010) .
• Typical permitted uses: Apartments, condos, townhouses, senior projects; incidental uses include home occupations and day care as accessory uses (§ 18.44.020) .
• Key standards:
  • Minimum density: 30 dwelling units per acre (minimum) — density bonus options are available under the affordable housing provisions (§ 18.44.040) .
  • Height: up to 45 ft / 3.5 stories (§ 18.44.050 B) .
  • Front yard: 15 ft (§ 18.44.050 C.1) and side/rear yard rules vary depending on adjacency to single‑family zones (§ 18.44.050 C.2–3) .
  • Open green area: minimum 25% of lot area (§ 18.44.050 F) .
• Where it applies: As shown on the official zoning map and used by the Affordable Housing Overlay (§ 18.40.050 references AHO boundaries) .

Commercial / Highway Commercial and Specific Plan commercial chapters (examples)

• The code contains multiple site- and center-specific commercial chapters and specific plans, each with its own Area‑by‑Area standards — see Specific Plan No. 18 (Chapter 18.530), Specific Plan No. 13 (Chapter 18.528), and other specific-plan chapters (§ 18.530, § 18.528, § 18.532) which set setbacks along arterial streets such as Arrow Highway, Via Verde, and San Dimas Avenue and specify height and landscaping standards. For example:
  • Specific Plan No. 18 Area I: 25 ft setback along Arrow Highway/Lone Hill Ave; max height 30 ft (§ 18.530.140 D) .
  • Commercial/Highway chapter (18.532): setbacks along Arrow Hwy and Cienega Blvd: 25 ft for structures up to 18 ft, 40 ft for taller structures; max height 25 ft in many areas (§ 18.532.290, § 18.532.310) .
• Where it applies: These are geographically defined in each specific plan’s exhibits and on the official zoning map; read the applicable specific-plan chapter for parcel-level rules (§ 18.528, § 18.530, § 18.532) .

RPD (Residential Planned Development overlay) — RPD

• Purpose: An overlay that allows flexibility in design and special development standards to produce superior planned developments; RPD is appended after the base zone on the official map and applies only over single‑family zones like S‑F or SF‑A (§ 18.52.010) .
• Typical uses and standards: Uses permitted in the underlying zone plus approved open-space and amenity provisions; RPD standards may replace underlying standards if the planning commission finds the RPD produces a superior result (§ 18.52.010–030) .

Scenic Highway Overlay — SHO

• Purpose and effect: Adds landscape, setback, undergrounding of utilities and design rules to properties adjacent to designated scenic highways; the overlay is appended to the base zone on the official map as SHO and the code lists specific required yards for streets like Foothill Boulevard and Via Verde (e.g., 25 ft for Foothill) (§ 18.108.030–040) .

Quick decision table — selected standards and code references

Practical guidance & interpretation notes

• Always start by checking the official zoning map (§ 18.16.020) to identify the base zone and any overlays on your parcel; the map controls use and is the primary source for determining which chapter applies.
• If your parcel sits inside a specific plan (Downtown Specific Plan, Specific Plan No. 18, No. 13, etc.), read that specific-plan chapter first: the specific plan sets tailored land‑use and development standards and may supersede or augment the Code (§ 18.50.040) .
• For multi‑family feasibility use the MF and MF‑30 standards (density, heights, yards, minimum open-green percentage) to quickly test unit counts and massing (§ 18.42 and § 18.44) .
• Design-review and development-plan approvals are common: many chapters require development-plan approval under Chapter 18.12 before permits are issued (see e.g., § 18.42.060, § 18.48.050) — include design-review strategy in early planning.
• Parking standards are implemented in a separate chapter (Chapter 18.156). Consult the parking rules early for commercial and multi‑family projects.
• Detached ADUs are regulated elsewhere in the code (see Chapter 18.38 cross‑references in several specific-plan chapters); consult the ADUs page and § 18.38 for ADU-specific rules (the specific plan or zone may still impose siting constraints).

Checklist (what an applicant must satisfy before building in San Dimas zoning terms)

• Confirm the parcel’s base zone and overlay labels on the official zoning map (§ 18.16.020) .
• Check whether the parcel lies inside a specific plan and follow that chapter’s land‑use table and subarea rules (§ 18.50.020–040) .
• Verify permitted uses in the applicable zone chapter (e.g., MF, MF‑30, SF‑A, specific-plan area chapters) and whether your use needs a conditional-use permit (§ 18.42.020, § 18.44.020, § 18.28.020) .
• Apply development plan and design-review applications where required (Chapter 18.12 and zone-specific references such as § 18.42.060, § 18.48.050) .
• Confirm dimensional standards (setbacks, height, lot coverage, open green area) in the relevant chapter (e.g., § 18.42.050, § 18.44.050, § 18.532.290) .
• Check parking requirements in Chapter 18.156 and site‑specific parking ratios listed in specific-plan chapters; include parking in the development plan submittal (parking).
• Confirm overlay implications (AHO, DS, SHO, RPD) — overlays change setbacks, densities or review procedures (§ 18.40, § 18.26, § 18.108, § 18.52) .
• Consult the planning department for any nonconforming-use, variance, or subdivision issues (Chapters 18.200, 18.204, 18.208 cross-referenced in parcel-level rules). Not all administrative or appeal processes are summarized here.

Risks & Ambiguities

Plain-English Summary

San Dimas zoning is map‑driven: find your parcel on the official zoning map, then read the associated Code chapter (and any specific plan or overlay chapter) for permitted uses, setbacks, heights and required review steps — common multi‑family and commercial areas have explicit numeric standards (e.g., MF‑30 requires 30 du/acre; many commercial specific plans require 25 ft arterial setbacks). Always confirm overlays and specific-plan exhibits with planning staff before assuming standards. (§ 18.16.020, § 18.44.040, § 18.530.140)

Source References

• Official zoning map adoption and rules: § 18.16.020
• MF zone (Multiple‑Family) standards and uses: Chapter 18.42, esp. § 18.42.010–050
• MF‑30 zone (Thirty units/acre): Chapter 18.44, esp. § 18.44.010–050
• SF‑A single‑family agriculture: Chapter 18.28, esp. § 18.28.010–020
• Development standards overlay zone (DS): Chapter 18.26, § 18.26.010–030
• Affordable Housing Overlay (AHO): Chapter 18.40, § 18.40.010–050
• Scenic Highway Overlay (SHO): Chapter 18.108, § 18.108.030–040
• Specific plans and downtown: Chapter 18.50 (Downtown Specific Plan) and specific-plan chapters such as 18.528, 18.530, 18.532 for parcel-level commercial standards (see § 18.50.020–040, § 18.528.080, § 18.530.140, § 18.532.130–310)
• Design review / development plan references: Chapter 18.12 (cross‑referenced throughout; e.g., § 18.42.060)
• ADUs: local cross‑references to Chapter 18.38 appear in specific‑plan chapters (e.g., § 18.518.100); consult local ADU page and Chapter 18.38 for detailed ADU rules

Also consult the city pages on development standards, parking, design review, overlay districts, ADUs, and the California Building Standards Code for topics linked to but outside Title 18.

Retrieved passages

• San Dimas Zoning Code (§ 1) High relevance show source text
• San Dimas Zoning Code (chapter may) High relevance show source text
• San Dimas Zoning Code (§ 1) High relevance show source text
• San Dimas Zoning Code (chapter which) High relevance show source text
• San Dimas Zoning Code (§ 1) High relevance show source text
• San Dimas Zoning Code (§ 18.26.010.) High relevance show source text
• San Dimas Zoning Code (§ 1) High relevance show source text
• San Dimas Zoning Code (title shall) High relevance show source text
• San Dimas Zoning Code (§ 18.42.060.) High relevance show source text
• San Dimas Zoning Code (§ 18.44.030.) High relevance show source text
• San Dimas Zoning Code (§ 2) High relevance show source text
• San Dimas Zoning Code (§ 1C) High relevance show source text
• San Dimas Zoning Code (§ 2) High relevance show source text
• San Dimas Zoning Code (§ 1) High relevance show source text

Cited sections

• Official zoning map adoption and rules: § **18.16.020**
• MF zone (Multiple‑Family) standards and uses: Chapter **18.42**, esp. § **18.42.010–050**
• MF‑30 zone (Thirty units/acre): Chapter **18.44**, esp. § **18.44.010–050**
• SF‑A single‑family agriculture: Chapter **18.28**, esp. § **18.28.010–020**
• Development standards overlay zone (DS): Chapter **18.26**, § **18.26.010–030**
• Affordable Housing Overlay (AHO): Chapter **18.40**, § **18.40.010–050**
• Scenic Highway Overlay (SHO): Chapter **18.108**, § **18.108.030–040**
• Specific plans and downtown: Chapter **18.50** (Downtown Specific Plan) and specific-plan chapters such as **18.528**, **18.530**, **18.532** for parcel-level commercial standards (see § **18.50.020–040**, § **18.528.080**, § **18.530.140**, § **18.532.130–310**)
• Design review / development plan references: Chapter **18.12** (cross‑referenced throughout; e.g., § **18.42.060**)
• ADUs: local cross‑references to Chapter **18.38** appear in specific‑plan chapters (e.g., § **18.518.100**); consult local ADU page and Chapter **18.38** for detailed ADU rules
• SanDimas_ZoningCode.md

• Official San Dimas code library