Ontario, CA Accessory Structures: Shed & Carport Rules (2026)
Shed permit rules in Ontario, CA, also referred to as storage shed, backyard shed, or accessory building regulations, set size limits, setbacks, and when a building permit is required.
Key Facts
- Code Section
- Ontario Development Code 5.03.011; Table 5.03-1
- Max height (by right)
- 16 ft (35 ft with CUP)
- Max area (by right)
- 650 sq ft (1,100 sq ft for required garage parking)
- Rear setback
- 5 ft (under 25 ft wide); 10 ft (25 ft+ wide)
- Street side setback
- 10 ft
- Interior side setback
- 10 ft (AR-2/RE-2); 0-5 ft other districts
- Separation
- 6 ft between structures; 50 ft from major pipelines
- Location
- Rear one-half of lot; interior side/rear yard only
- Combined area cap
- Greater of 50% of primary GFA or 650 sq ft without CUP
- Kitchen
- Prohibited (excluding outdoor kitchens)
- Shipping containers
- Prohibited as residential storage
Summary
Ontario Development Code Section 5.03.011 governs detached accessory residential structures such as storage sheds, capping permitted-by-right area at 650 square feet (up to 1,100 for required garage parking) and 16 feet in height, requiring 5-foot rear and 10-foot interior side setbacks, prohibiting kitchens, and barring placement in front yards or shipping containers as storage.
5.03.011: Accessory Residential Structures. A. Purpose. The purpose of this Section is to establish standards for the construction and use of Accessory Residential Structures (other than Accessory Dwelling Units allowed pursuant to Section 5.03.010 of this Development Code) in conjunction with existing single-family dwellings located within single-family or multiple-family zoning districts. B. Applicability. For purposes of this Section, the herein established development standards shall apply to Accessory Residential Structures such as garages, carports, guesthouses, storage sheds, pool houses, recreation rooms, etc., which are incidental or subordinate to the primary dwelling. ... D.4. An Accessory Residential Structure that is detached from the primary residential structure shall be located on the rear one-half of the lot on which it is constructed. ... 10. No shipping container or other similar container shall be located on any residentially zoned property to accommodate the on-site storage of tools, vehicles, equipment, and other materials.
Full Breakdown
011 of the Ontario Development Code establishes standards for accessory residential structures other than ADUs, including garages, carports, guesthouses, storage sheds, pool houses, and recreation rooms that are incidental or subordinate to the primary dwelling on a lot containing a single-family dwelling. A detached accessory structure is permitted by right up to 16 feet in height and 650 square feet of area (or 1,100 square feet to accommodate required garage parking); structures over 16 feet in height or over 650 square feet require a Conditional Use Permit, up to a 35-foot height maximum and an area deemed appropriate by the approving authority.
03-1, minimum setbacks for a detached accessory structure are 10 feet from a street side property line, 10 feet from an interior side line in AR-2/RE-2 (0 to 5 feet in other districts), 5 feet from the rear line for structures under 25 feet wide (10 feet if 25 feet or wider), and 6 feet from an alley line for alley-facing garages; a 6-foot separation between structures and 50 feet from major pipelines is also required. Child play structures, doghouses, and similar structures in a screened side or rear yard have no required setback.
An accessory structure must be located on the rear one-half of the lot, within an interior side or rear yard, and may not be placed in front yards, street side yards of corner lots, or in front of the main dwelling. The sum of all accessory residential structures (excluding ADUs) may not exceed 50 percent of the primary dwelling's gross floor area or 650 square feet, whichever is greater, without a CUP. No accessory residential structure may contain a kitchen or cooking facilities (excluding outdoor kitchens), and no shipping container or similar container may be located on residentially zoned property for on-site storage of tools, vehicles, equipment, or materials.
Structures with noise-generating mechanical equipment must be set back at least 5 feet from interior side or rear lines, and the lot must maintain a usable rear yard (minimum 20 feet for a traditional single-family lot, 10 feet for a small lot).
Violations & Fines
Building or maintaining a detached accessory structure that exceeds the permitted-by-right height (16 feet) or area (650 square feet) without a Conditional Use Permit, that encroaches on the Table 5.03-1 setbacks, that is placed in a front yard, or that includes a prohibited kitchen or shipping container, is a Development Code violation subject to code-enforcement action, including abatement, after-the-fact permitting, and potential CUP requirements. The Planning Director may require a recorded restrictive covenant before issuing a building permit for an accessory residential structure.
Frequently Asked Questions
How big can a shed be in Ontario, CA without a permit hearing?
Where can I place a shed on my Ontario lot?
Can I put a shipping container in my Ontario backyard?
Can a shed have a kitchen in Ontario?
Sources & Official References
Other rules in Ontario
How Ontario compares: Shed Permit Requirements by City·California rules heatmap·Compare Ontario to another location·View the California accessory structures overview
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