How Ontario Handles Fence Regulations: A Practical Guide
Ontario maintains 126 local ordinances across all categories, and 5 of those deal specifically with fence regulations. Here is a breakdown of what the city actually requires, what is prohibited, and where Ontario falls on the strict-to-permissive spectrum compared to other cities.
Retaining Walls
Where grade differs between properties or a property and the public right-of-way, Ontario allows a wall or fence combined with a retaining wall above the normal height limit, but a retaining wall adjacent to the public right-of-way is capped at 3 feet, with a free wall up to 6 feet and an overall height of 9 feet; deeper cuts must be tiered.
Key details: Retaining wall max near ROW: 3 ft. Free wall max near ROW: 6 ft. Overall max near ROW: 9 ft. Tiering required: When over 3 ft of retention adjacent to ROW. Code Section: Development Code 6.02.020.C.5-C.6.
Over-height or untiered retaining walls adjacent to the right-of-way require Planning Director approval; unapproved work is subject to stop-work orders and Community Improvement enforcement, plus building-permit penalties for walls over 2 feet built without a permit.
Neighbor Fence Rules
Ontario lets neighbors build a wall or fence on a common interior side or rear property line for division or security. On corner lots and in front yards the area between a fence and the sidewalk or curb must be fully landscaped and maintained, and nothing may be placed in the public right-of-way without an encroachment permit.
Key details: Shared side/rear line: Fence allowed on common line for division or security. Front yard fence location: Up to 3 ft along front/street-side line; landscape strip required. Through-lot rear: Fence min. 5 ft behind rear property line. Right-of-way: Encroachment permit required; remove within 7 days of notice. Code Section: Development Code 6.02.020.D; Cal. Civ. Code 841.
Encroachments in the right-of-way must be removed by the owner within 7 days of notice or the City removes them at the owner's expense (6.02.015.D). Required landscaping strips and approved locations are enforced through Planning Director review (6.02.005.B) and Community Improvement.
Material Restrictions
Ontario prohibits razor wire on any wall or fence citywide, and bans barbed wire and electrified fences in residential, commercial, and residential mixed-use districts. Residential fences must be ornamental steel/iron, wood, PVC, or decorative masonry; chain link in front and street-side yards is allowed only where it is the predominant existing material.
Key details: Razor wire: Prohibited on all walls/fences citywide. Barbed wire: Banned in residential and commercial zones; OK industrial if not visible above wall. Electrified fence: Banned in residential zones; misdemeanor if unlawfully installed. Residential fence materials: Ornamental steel/iron, wood, or PVC. Code Section: Development Code 6.02.010, 6.02.020.B.
Prohibited materials are abated through Planning Director review and Community Improvement enforcement (6.02.005.B). Installing or operating an electrified fence in violation of the code is expressly declared unlawful and a misdemeanor (6.02.025.E.1.i).
Height Limits
In Ontario residential zones, walls and fences within a front yard may not exceed 3 feet, while interior side, rear, street-side, and subdivision-perimeter walls or fences may not exceed 6 feet. Anything in a required front or street-side setback that affects safe sight lines is capped at 3 feet.
Key details: Front yard max (residential): 3 ft. Side / rear / street-side max: 6 ft. Subdivision perimeter wall: 6 ft (decorative masonry required). Measurement: Top of wall to lowest adjacent finished grade, exterior side. Code Section: Development Code 6.02.020.C.
Walls and fences are subject to review and approval by the Planning Director regardless of whether a building permit is required (6.02.005.B). Over-height fences are enforced by Community Improvement; structures placed in the right-of-way must be removed by the owner within 7 days of notice or the City removes them at the owner's expense (6.02.015.D).
Fence Permit Requirements
Every wall, fence, and gate in Ontario is subject to Planning Director design review regardless of whether a building permit is needed. A building permit is separately required for fences and walls over 3 feet high and for retaining walls over 2 feet, and a right-of-way encroachment permit is required for anything in the public right-of-way.
Key details: Planning design review: Required for all walls/fences/gates (even if no building permit). Building permit threshold (fences): Over 3 ft high from grade. Building permit threshold (retaining walls): Over 2 ft (footing to top). Right-of-way: Encroachment permit from City Engineer. Code Section: Development Code 6.02.005.B; Building Permit FAQs.
Construction without required Planning review or building permits can trigger stop-work orders and Community Improvement enforcement. Unpermitted encroachments in the right-of-way must be removed by the owner within 7 days of notice or removed by the City at the owner's expense (6.02.015.D).
The Bottom Line
Ontario's fence regulations rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming Ontario is broadly strict or permissive.
These rules come from Ontario's publicly available municipal code. For complete penalty schedules, exemption details, and answers to common questions, see the individual ordinance pages throughout this guide.