Ontario | Parking, setbacks and height

Ontario, California Parking, Setbacks and Height: House Setbacks, Lot Coverage, Height Limits, Parking Counts, Driveways and Ways to Vary a Standard

This page gives the size and placement rules for buildings in the City of Ontario: how far a home must sit from each property line (the setback), how tall it may be, how much of the lot it may cover, and how many parking spaces it needs. The rules are in Chapter 6.0 of the Ontario Development Code. Ontario measures the front setback by the class of the street, so the same house needs 20 feet on a local street and 30 feet on an arterial street. The Ontario overview has the summary.

Setbacks for a House

Source: Ontario Development Code, Section 6.01.010, Table 6.01-1, Traditional Single-Family Residential Development Standards (Rev. 08.18.2026). The table prints one 30-foot figure for AR-2 and RE-2 on collector and local streets.

An arterial street is a main through road, a collector street gathers traffic from a neighborhood, and a local street serves the homes on it. The City's Mobility Plan map sets the class of each street, and this guide did not read that map. Four notes to the table change the result on some lots.

• Parking at the back with no alley. "When vehicle parking is provided at the rear of a lot (whether within a garage or carport, or uncovered) that does not have alley access, a minimum 10-FT interior side building setback" is required, to keep vehicle access to the rear of the lot clear.
• A usable rear yard. "A traditional single-family lot shall maintain a useable rear yard area having minimum horizontal dimension of 20 FT in any direction and a clear vertical dimension of 8 FT."
• Private streets. The setback from a private street is measured from a line "12 FT behind face-of-curb."
• Garage doors. For a detached garage, Table 5.03-1 says doors facing a public street "shall be setback a minimum of 20 FT behind the street property line (minimum 18 FT behind the street property line if an overhead rollup garage door is provided)."

Small lot homes use their own tables. A small lot traditional home needs 14 feet from a collector or local street to living area and 18 feet to a garage entry, a side setback of 5 feet that may drop to 4 feet when paired with the neighbor's side yard, and 10 feet at the rear for living area. Cluster homes need 4 feet at interior sides and rear and 10 feet from the project boundary.

What May Extend Into a Setback

Section 6.01.010.D lists the parts of a building that may cross a setback line.

• Porches, patios and decks. Up to "30 percent into a required street setback area, provided the porch, patio, or deck, is no greater than 20 FT in width."
• Eaves and similar features. "a maximum of 50 percent of the required setback, not to exceed 2.5 FT."
• Fireplaces and chimneys. "a maximum of 2 FT," with the side setback never less than 3 feet.
• Patio covers. Posts and beams of a patio cover attached to a house may reach "to within 10 FT of the rear property line, to within 5 FT of an interior property line and to within 5 FT of a street side property line."
• One-story additions. "Single-story additions to single-family dwellings may extend into a required rear setback to within 10 FT of the rear property line, provided the building addition does not occupy more than 25 percent of the required rear setback area."
• Open stairs and balconies. Up to 4 feet, with the side setback never less than 2.5 feet.

Height

Sources: Ontario Development Code, Tables 6.01-1, 6.01-2A, 6.01-2B, 6.01-2C and 6.01-3 and Section 6.01.010.G; Table 5.03-1 and Section 5.03.010 (Rev. 08.18.2026).

• How height is measured. Chapter 9.0 measures "from the lower of existing grade or finished grade elevation to the highest point of the roof, not including chimneys, antennas, or other appurtenant structures."
• Features above the limit. Chimneys, cupolas, elevator penthouses, parapet walls and similar structures "may be erected to a height of up to 25 percent above the prescribed height limit of the base zoning district."
• Next to houses. Under the 2025 design standards, a multiple-family building "within 100 feet of single-family residential dwellings must not exceed 35 feet or the height of adjacent residential buildings, whichever is greater."
• Airport limits. Each standards table says properties in the Airport Influence Area "shall be subject to the requirements and standards of the ALUCP," the airport compatibility plan. See the airport zones and specific plans page.
• SB 9 homes. The City sections on two-unit projects and urban lot splits print 16 feet and one story for new homes on lots of 2,000 square feet or more. The ADUs and SB 9 page compares that with the statute.

Lot Coverage and Yards

Lot coverage is the share of the lot under buildings. Chapter 9.0 defines it as "The area devoted to principal and accessory structures on a lot, including patios enclosed on 3 sides, garages, and covered parking." Table 6.01-1 allows 30 percent in AR-2, 40 percent in RE-2 and RE-4, 50 percent in LDR-5 and 60 percent on a traditional lot in the four higher zones. Small lot homes may cover 55 percent in LDR-5, 60 percent in MDR-11 and 70 percent in MDR-18, MDR-25 and HDR-45. Multiple-family projects use project coverage: 60 percent in the MDR zones and 100 percent in HDR-45.

• Front yard paving. "A maximum of 45 percent of the front yard of traditional single-family lots, including the street side yard area of corner lots, that is open to public view may be comprised of hardscape materials," which the code lists as paving, gravel, decomposed granite and artificial turf.
• Landscaping. Front and street side yards of single-family lots "shall be fully landscaped and provided with an automatic irrigation system."
• House width. A traditional single-family dwelling "shall have a minimum overall width of 24 FT."
• Infill houses. A new house in an existing neighborhood must be "compatible with existing residential development in the surrounding neighborhood" in area, dimensions, lot coverage, height, bulk and scale, and its garage follows the pattern of the block, with alley access where the lot has an alley.
• Roof equipment. On single-family dwellings, "The placement of new exterior roof-mounted mechanical, heating and air conditioning equipment is prohibited."
• Pipelines. Every table sets "50 FT (to any habitable structures)" from the major fuel pipelines that cross the city.

Parking Counts

Sources: Ontario Development Code, Section 6.03.015, Table 6.03-1 (Rev. 12.01.2020) and Section 6.01.010.G; Sections 5.03.010 and 5.03.403 (Rev. 08.18.2026).

• Rounding. "one parking space shall be required for a fractional unit of 0.50 or greater, and no space shall be required for a fractional unit of less than 0.50."
• More is allowed. "For residential uses, there is no maximum limit as to the number of parking spaces that may be provided."
• On the same lot. Required residential spaces must be on the same lot as the homes they serve.
• Assigned spaces. A multiple-family project of 3 or more homes files a Parking Management Plan that assigns each resident space to a home, and "It shall be unlawful to rent or lease a required residential parking space" apart from the home it serves.
• Garage conversions. "No garage shall be converted to another use unless a replacement garage is constructed on-site," except a conversion to an ADU.
• Existing homes. "No existing land use shall be deemed nonconforming solely based upon the lack of off-street parking or loading spaces required by this Division."

A worked example, as VanPlex arithmetic from the table: a fourplex of two-bedroom homes needs 4 times 2.0, or 8 resident spaces, four of them in garages or carports, plus 4 times 0.25, or 1 guest space, for 9 spaces. The three-guest-space minimum starts above 8 dwellings.

Space Sizes, Tandem Parking and Driveways

• Space sizes. Table 6.03-2 sets a garage or carport space at "10 FT wide by 20 FT long," an open standard space at 9 by 18 feet, a parallel space at 8 by 24 feet, and a tandem pair at 9 by 34 feet. A space next to a wall or fence gets one more foot of width.
• Drive widths. A single-family driveway is at least 10 feet wide. A two-way driveway for a residential project is 20 feet, and a two-way drive aisle with parking on it is 24 feet.
• Tandem parking. In a multiple-family project, tandem spaces may serve resident parking, "Both automobile spaces shall be assigned for use by the same dwelling unit," and they "may be counted toward a maximum of 12 percent of the resident parking space requirement." Guest spaces "shall not be designed in a tandem configuration." For a house, tandem spaces are allowed only when "provided in excess of the minimum parking" required.
• One driveway. On a single-family lot, "One driveway per lot may be permitted, which shall lead to a garage or carport, and shall not exceed the overall width of the garage or carport."
• Drive approach. Table 6.01-7 limits the approach to 12 feet on a lot less than 51 feet wide, 16 feet on a lot of 51 to 80 feet, and 20 feet on a wider lot.
• Stored vehicles. Vehicles may not be stored in a front or street side yard, and "stored" means "continuously parked in the same location for more than 72 hours."
• Projects of five or more homes. The drive approach gets enhanced paving, such as pavers or stamped concrete, from the street to the first aisle or space.

Garages, Sheds and Walls

Section 5.03.011 covers accessory residential structures on a lot with a house: detached garages, carports, guesthouses, sheds and pool houses.

• Size and height by right. Table 5.03-1 allows 16 feet of height and 650 square feet, or 1,100 square feet "to accommodate garage parking required for uses on the affected property." Above either number, a Conditional Use Permit is required.
• Placement. A detached structure "shall be located on the rear one-half of the lot." It sits 5 feet from the rear line if it is under 25 feet wide and 10 feet if wider, and 6 feet from other structures. A detached garage on a public alley sits 6 feet from the alley line.
• Total area. All accessory structures on a lot, leaving out ADUs, may total "no more than 50 percent of the GFA of the primary residential structure or 650 SF, whichever is greater," without a Conditional Use Permit. GFA is gross floor area.
• No kitchen. "An Accessory Residential Structure shall not contain a kitchen or cooking facilities." A guesthouse is limited to 650 square feet.
• Carports. "Carports shall not be permitted in lieu of a garage required pursuant to the provisions of Table 6.03-1."
• Walls. Section 6.02.020 requires 6-foot masonry block walls on the interior side and rear lines of single-family projects, and the general rule holds walls, fences and hedges that affect safe access to 3 feet in a front or street side setback.

Three Ways to Vary a Standard

• Administrative Exception. Section 4.03.055 allows "reductions of up to 10 percent" from setback and building separation rules where the result is a better site or building design. No hearing is held, and adjoining owners are notified and invited to comment. It may not change lot size, density or height.
• Minor Adjustment. Section 4.02.020 allows "A reduction of up to 25 percent from minimum setback and separation requirements" or "A 10 percent increase in the maximum height of structures." Owners with a common property line are notified, and a hearing is held only if someone asks. It "shall not be approved for reductions in minimum lot size, lot coverage, lot dimension, landscape coverage, parking requirements, or for an increase in maximum density or floor area ratio."
• Variance. A Variance may depart from "any numerical development standard," except density and floor area ratio. Five findings are required, among them that "There are exceptional or extraordinary circumstances or conditions applicable to the property involved." Table 2.02-1 sends a homeowner's variance to the Zoning Administrator and other variances to the Planning Commission.
• Parking reductions. Section 6.03.020 allows a reduction for shared parking or low demand under a recorded agreement, and Table 2.02-1 lists Parking Reduction as a Planning Commission decision.

The Planning fee schedule of August 22, 2026 lists a Variance for a homeowner at $336.00, a Variance for other applicants at $5,704.65, and an Administrative Exception or Minor Adjustment at $4,511.85. Hearing fees are added: $81.00 for a homeowner before the Zoning Administrator and $722.00 for others. Table 2.02-1 cites Administrative Exceptions to "Section 4.03.050," and the section is numbered 4.03.055 in Chapter 4.0.

Where State Law and Other Documents Change the Numbers

• ADUs. State ADU law sets 4-foot side and rear setbacks and its own height and parking rules, which Section 5.03.010 repeats. The tables on this page govern the main home.
• SB 9. The City sections say zone setbacks "shall yield to the degree necessary" to allow two homes of 800 square feet, with no structure closer than 4 feet to a side or rear line.
• Multiple-family street setbacks. Table 6.01-3 and the 2025 design standards print different street setbacks for multiple-family buildings. The three or more homes page has both sets.
• Specific plans and PUDs. A lot inside a specific plan or Planned Unit Development follows that document's setbacks, heights and parking in place of these tables.

Limits of This Page

The Chapter 6.0 file is named "Rev 08-18-2026." The pages of Division 6.01 print "Rev. 08.18.2026" and the pages of Division 6.03, the parking division, print "Rev. 12.01.2020." City Council agendas from January 7, 2025 to October 6, 2026 were read for later changes. The Mobility Plan map that classes each street, Reference D (the Residential Design Guidelines), the specific plans and the PUD documents were not read. Division 6.10, which the tables cite for property appearance, is marked "Reserved for Future Use" in the posted chapter. Ask the Planning Department to confirm the street class and the setbacks for your lot.

Where to Go Next

Related on VanPlex: the Ontario overview, the California ADU law page and the California lot eligibility page.

Frequently Asked Questions

Official sources (checked October 2026)