Ontario — Design Review

Last reviewed: July 3, 2026

Overview

Ontario's local design-review process is implemented primarily through the Development Plan procedure in the Ontario Development Code (commonly called the Development Code rather than "Title 17"). The Development Plan review (the City's vehicle for architectural/site design review) establishes when design/site/architectural review is required, the matters to be evaluated, and what findings and conditions the Approving Authority may impose. See § 4.02.025 for the controlling rules on Development Plans and design-related review triggers and findings.

When you read this page, note the difference between (1) the Development Plan discretionary design review process (controls overall architectural/site design and many discretionary conditions) and (2) ministerial or administrative processes that allow limited departures (e.g., Administrative Exceptions). Both are part of the Development Code and are cited below. Relevant development standards and landscape/parking rules that the reviewer enforces live in Division 6.01, 6.03, and 6.05 of the Development Code.

(First-use links: the text below hyperlinks the main related topics used in this page: design review, parking, development standards, overlays, ADUs, and the state building-code reference.)

What "Design Review" means in Ontario

• The City calls the design-review function a Development Plan review: approval, approval with modifications, or denial of a Development Plan based on findings about site layout, building architecture, materials, colors, landscaping, signs, parking layout, pedestrian access, and related items. See § 4.02.025.
• Review authority and review matrix: Table 2.02-1 identifies the Approving Authority (Planning Director, Zoning Administrator, Planning Commission, City Council, and advisory bodies) for Development Plan actions and related reviews. See Division 2.02 and Table 2.02-1.

How Design Review is Triggered (Key Triggers)

The Development Code lists explicit triggers that make a Development Plan mandatory; the most decision-relevant triggers are summarized in the table and grounded in the code.

Practical note: even where an application is not strictly required, the Approving Authority can require Development Plan review where the design implications are substantive—so "check with staff" remains essential. Verify with the jurisdiction.

District-by-district (how design review interacts with zoning districts)

Design review (Development Plan review and the standards the reviewer enforces) works across all zoning districts. Below are district-specific breakdowns that are relevant for design review. Each subsection summarizes the district's purpose and the standards the Development Plan reviewer will check. For the detailed dimensional tables and permitted-use lists consult the referenced subsections and tables.

LDR‑5 (Low Density Residential) — typical single‑family environments

• Purpose & where it applies: neighborhood low-density residential developments; standards and guidelines appear in Division 6.01, Subsections/tables for small‑lot and traditional single-family projects.
• Typical permitted uses: single‑family detached homes, accessory uses (ADUs subject to ADU rules). See Division 6.01 and ADU rules in Division 5.03.
• Key dimensional standards the reviewer enforces during design review: front/street setbacks (examples: 20 ft from freeways, 30 ft from arterials; collector/local street living area and garage entry setbacks are published in the residential tables), side/rear setbacks, and maximum building height 35 ft for typical single‑family forms. See Table 6.01‑2A and related text in § 6.01.010.
• Design-review focus: building orientation, garage placement, front elevations, landscaping, and pedestrian access; reviewers will verify consistency with the residential design standards and historic preservation rules when relevant.

MDR‑11 / MDR‑18 / MDR‑25 / HDR‑45 (Medium/High density residential)

• Purpose & where it applies: multi‑family and compact housing forms where density ranges from MDR‑11: 5.1–11 du/ac through HDR‑45: 25.1–45 du/ac; design guidance and required open‑space minimums are in Division 6.01 and Division 5.03.
• Typical permitted uses: townhomes, apartments, mixed‑use where allowed (subject to MU or PUD rules).
• Key dimensional standards: project density bands listed in Table 6.01‑2C; open‑space minima (private/common/total) are specified for MDR categories (e.g., private open‑space 200 SF for MDR‑11; see Table and § 6.01.010).
• Design‑review focus: massing and compatibility with adjacent lower‑density neighborhoods, vehicle‑pedestrian circulation, required open space and landscaping, noise and airport/AIA impacts where applicable.

MU‑3, MU‑6, MU‑8B (Mixed‑Use districts: East Guasti, East Holt, Mountain/Fourth)

• Purpose & where it applies: planned mixed‑use development zones; many MU districts require a Planned Unit Development (PUD) before building permits. See MU‑3, MU‑6, and MU‑8B text in Division 6.01.
• Typical permitted uses: residential (low‑rise multi‑family), commercial retail, office (FAR caps apply — e.g., MU‑3 commercial/office not to exceed 1.0 FAR; MU‑6 office up to 2.0 FAR in some cases).
• Key dimensional standards: MU‑3 limits to 5 stories and density bands (e.g., 20–65 du/ac in MU‑3); MU‑6 and MU‑8B have stated max FAR and density ranges in Division 6.01.
• Design‑review focus: because most MU zones require PUDs, design review is often embedded in the PUD/Development Plan stage; reviewers emphasize ground‑floor activation, façade treatment, coordinated colors/materials, and integration of parking and public space.

Industrial districts (BP / IP / IL / IG / IH and related)

• Purpose & where it applies: employment, manufacturing, logistics, and distribution; industrial design rules and Industrial Design Guidelines are adopted as Reference F.
• Typical permitted uses: industrial, warehouse, assembly, and some commercial/office support uses (see Table 6.01‑10).
• Key standards and design expectations: truck circulation and screened loading, 360‑degree building treatment, screening of ground equipment, and landscape shading of parking. Industrial Design Guidelines are enforceable and used during Development Plan review.

AG (Agricultural overlay) and special overlays

• Where it applies: properties identified with the AG overlay and other overlays listed in Division 6.01 and Table 6.01‑12. These may sit on top of base zoning.
• Key standards: AG overlay requires minimum lot sizes (example: 10 acres) and sets one dwelling per 10 acres in the overlay; refer to Table 6.01‑12 for the numeric standards. Overlays often have their own design rules the reviewer enforces during Development Plan review.
• Design‑review focus: compatibility with agricultural uses, preservation of open space, and compliance with overlay‑specific development standards.

How the Approving Authority evaluates design

The Development Plan purpose enumerates the review topics: building location; parking and loading layout; street and pedestrian design; walls/fences; landscape type and extent; hardscape and drainage; exterior architecture, materials and colors; construction quality; and signs — all required evaluation items are listed in § 4.02.025(A). Approving Authorities may impose conditions on height, bulk, setbacks, landscaping, screening, parking, circulation, and more. § 4.02.025 and related Findings language govern approval criteria.

Design guidelines (Downtown Ontario Design Guidelines, Industrial Design Guidelines, Landscape Design and Construction Guidelines) are referenced and enforceable as guidance or mandatory elements depending on the district; the Development Plan reviewer will compare proposals to these references as applicable. See the Downtown Guidelines referenced as Development Code Reference "C" and Industrial Guidelines as Reference "F".

Interaction with specific standards you must submit or meet

• Landscaping plans: Required with a Development Plan; preliminary Landscape Plans and full Landscape and Irrigation Construction Documentation Plans are governed by § 6.05.015, including MAWA/ETWU water budget requirements and registered landscape architect seals where applicable.
• Parking & circulation: Off‑street parking quantities and design are enforced per Division 6.03 and Table 6.03‑1; parking is flagged for review whenever Development Plan approval is required. See § 6.03.005 and § 6.03.015 for applicability and required counts.
• Signs: The Development Plan evaluation explicitly includes sign design among review items; separate Sign Plans and Division 8.1 rules apply as part of the review. § 4.02.025 cites signs as a review element.
• Materials and colors, screening of mechanical equipment, refuse enclosures, and roof screening are all subjects of review and are specifically addressed across Divisions 6.01, 6.05, and other district standards (examples: building colors and equipment screening).

Checklist — what an applicant must provide for Development Plan (design) review

• A completed Development Plan application filed per Division 2.02 and Table 2.02‑1 (Review Matrix).
• Site plan showing building footprints, parking layout, driveway aisles, loading, and circulation (required by § 4.02.025(A)(a–d)).
• Exterior elevations with materials and colors; photo or material samples to demonstrate coordinated palette (§ 4.02.025(A)(j)).
• Landscape schematic (preliminary landscape plan) and commitment to submit full Landscape & Irrigation Construction Documentation Plans (per § 6.05.015).
• Parking calculations and layout consistent with Division 6.03 and Table 6.03‑1; include ADA layout and potential parking management plan.
• Sign program or sign locations and concept (signs are a review topic per § 4.02.025 and Division 8.1).
• Trash/refuse enclosure design that meets enclosure standards and screening (see Division 6.01 and trash enclosure specs).
• For projects requiring additional studies: noise study, stormwater/grading hydraulics, and any ALUCP (Airport Influence Area) materials if located within the AIA. See Division 6.08 and airport references.

Risks & Ambiguities

Information Gaps

• Exact appeal timelines, current fee schedule for Development Plan review, and the City's current submittal checklist/format (electronic vs. paper) were Not found in retrieved materials — Verify with Planning and the Development Services counter.
• The parcel‑level applicability of historic‑resource status and any site‑specific overlay (Specific Plans, ONT district nuances) was Not found in retrieved materials — Verify with Planning staff and the City's GIS/parcel tools.
• The Development Code references specific "Reference" guideline documents (e.g., Landscape Design and Construction Guidelines, Downtown Ontario Design Guidelines, Industrial Design Guidelines). The full text of those reference documents themselves and their URLs were Not found in the retrieved materials; obtain the guideline PDFs from the City.

Plain‑English Summary

If you are proposing new buildings, 3+ units, a project that exceeds certain addition thresholds, or commercial work in certain districts in Ontario, expect a Development Plan (the local "design review") that evaluates site layout, architecture, landscaping, parking and signage; the rules and triggers are in § 4.02.025 and related district standards in Division 6.01, parking in 6.03, and landscaping in 6.05.

Source References

• Development Plans (Design Review): § 4.02.025 (Division 4.02 — Discretionary Permits and Actions).
• Administrative Exceptions (minor design departures): § 4.03.055 (Division 4.03 — Ministerial Permits and Decisions).
• District Standards and Mixed‑Use (MU) descriptions: Division 6.01 / MU district text (e.g., MU‑3, MU‑6, MU‑8B).
• Residential development standards and tables (LDR/MDR/HDR): § 6.01.010 and Tables 6.01‑2A/2C.
• AG (Agricultural) Overlay standards (Table 6.01‑12): Division 6.01.
• Off‑street parking: Division 6.03, § 6.03.005, § 6.03.015 and Table 6.03‑1.
• Landscaping requirements and Landscape Plans: § 6.05.015 and Division 6.05 (Landscape and Irrigation Plans / MAWA/ETWU).
• Industrial Design Guidelines and industrial district guidance: Division 6.01 and Industrial Design Guidelines (Reference "F").
• Downtown Ontario Design Guidelines referenced as Development Code Reference "C".

Retrieved passages

• Ontario Zoning Code Medium relevance show source text
• Ontario Zoning Code Medium relevance show source text
• Ontario Zoning Code Medium relevance show source text
• Ontario Zoning Code (Title 5) Medium relevance show source text
• Ontario Zoning Code (Section 65906) Medium relevance show source text
• Ontario Zoning Code Medium relevance show source text
• CBC § 2020 Medium relevance show source text
• Ontario Zoning Code (section are) Medium relevance show source text
• Ontario Zoning Code (Section 2.03.010) Medium relevance show source text
• Ontario Zoning Code Medium relevance show source text
• Ontario Zoning Code (Section 4.01.030) Medium relevance show source text
• Ontario Zoning Code (Section is) Medium relevance show source text
• Ontario Zoning Code (Section 65850) Medium relevance show source text
• Ontario Zoning Code Medium relevance show source text
• Ontario Zoning Code (section shall) Medium relevance show source text
• Ontario Zoning Code (Section 65591.) Medium relevance show source text
• Ontario Zoning Code (Section 65591.) Medium relevance show source text
• Ontario Zoning Code (Title 10) Medium relevance show source text
• Ontario Zoning Code Medium relevance show source text
• Ontario Zoning Code (Section 6.05.020) Medium relevance show source text
• Ontario Zoning Code (Title 10) Medium relevance show source text

Cited sections

• Development Plans (Design Review): **§ 4.02.025** (Division 4.02 — Discretionary Permits and Actions). (§ 4.02.025)
• Administrative Exceptions (minor design departures): **§ 4.03.055** (Division 4.03 — Ministerial Permits and Decisions). (§ 4.03.055)
• District Standards and Mixed‑Use (MU) descriptions: Division **6.01** / MU district text (e.g., MU‑3, MU‑6, MU‑8B).
• Residential development standards and tables (LDR/MDR/HDR): **§ 6.01.010** and Tables 6.01‑2A/2C. (§ 6.01.010)
• AG (Agricultural) Overlay standards (Table 6.01‑12): Division **6.01**.
• Off‑street parking: Division **6.03**, **§ 6.03.005**, **§ 6.03.015** and Table 6.03‑1. (§ 6.03.005)
• Landscaping requirements and Landscape Plans: **§ 6.05.015** and Division **6.05** (Landscape and Irrigation Plans / MAWA/ETWU). (§ 6.05.015)
• Industrial Design Guidelines and industrial district guidance: Division **6.01** and Industrial Design Guidelines (Reference "F").
• Downtown Ontario Design Guidelines referenced as Development Code Reference "C".
• Ontario_ZoningCode.md

• Official Ontario code library