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Fence laws in Ontario, California

What the Ontario municipal code says about fences, one topic at a time, with the section number and a link to the document behind every line. Where Ontario sets no rule of its own, the California rule is shown in its place and marked as such.

Fence laws in Ontario, California, question by question

The short version

Who pays on the line
Two neighbors split the cost of a fence on the line in California.
How tall
Ontario leaves fence height to the Planning Department, by proximity to the front, side or rear property lines.
Permits
Ontario needs a building permit for a fence over three feet, whatever it is made of. The figure is 3 feet, for height at which any fence starts needing a building permit.
Pool barriers
A pool fence in California stands at least sixty inches high. The figure is 60 inches, for minimum height of a pool enclosure.
Spite fences
A fence over ten feet tall in California is a private nuisance when it was put up or kept there to annoy the neighbor and the extra height serves no purpose. The figure is 10 feet, for spite fence threshold, with malice required.
Measured from what
Ontario uses two starting points in the same FAQ and the difference is deliberate.
Corner lots
California writes no clear view triangle into state law. It reaches the right of way of a state highway, whether or not the whole width is paved only.
Retaining walls
A retaining wall in Ontario needs a permit above two feet, and the two feet runs from the bottom of the footing to the top of the wall rather than from the ground. The figure is 2 feet, for retaining wall height from the bottom of the footing, before a permit is needed.
Materials
The Ontario permit list names five things and holds them all to the same three feet: concrete block walls, block pilasters, chain link, open or screened wrought iron fences and gates, and wood.
Livestock
California calls a fence lawful when it is strong enough to keep livestock from getting in or out. The figure is 4 feet, for height of the top wire on a lawful wire fence.

Who owns the fence between two properties in Ontario?

Compare fences on the property line across all 50 states

California answers this in its own law. The words that do it are quoted below.

Two neighbors split the cost of a fence on the line in California. The law starts from the idea that both get the same benefit from it, so both owe the same share of building it, keeping it up and replacing it. A neighbor about to spend that money gives the other one thirty days written notice first. Either neighbor can show the even split is wrong, and a court can then order less than half or nothing at all.

This one is California law, not Ontario law. All California findings

Adjoining landowners are presumed to share an equal benefit from any fence dividing their properties and, unless otherwise agreed to by the parties in a written agreement, shall be presumed to be equally responsible for the reasonable costs of construction, maintenance, or necessary replacement of the fence.

Civ. Code 841California Legislature · Read 13 September 2026

Also on fences on the property line in Ontario

  • set in state lawThe notice has to say six things: that the law starts from an even split, what is wrong with the fence now, what is planned instead, what it is expected to cost, how the cost gets shared, and when the work happens. Civ. Code 841(b)(1)California · Statute

How tall can a fence be in Ontario?

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Ontario does not set this. It leaves it to the Planning Department, by proximity to the front, side or rear property lines.

The Ontario building department does not publish a fence height limit and does not claim to. Asked how tall a fence may be, it points at the Planning Department and says the answer turns on how close the fence is to the front, side or rear property lines. So the three foot figure everywhere on this page is a permit threshold and not a ceiling, and the ceiling is set lot by lot by zoning rather than by one published number.

Please check with the Planning Department for the fence height limitation due to its proximity to the front, side, or rear property lines.

Building Permit FAQsCity of Ontario, Community Development, Building Department · Read 17 September 2026

The code hands this to the Planning Department, by proximity to the front, side or rear property lines, which is not published in the code itself.

Also on fence height in Ontario

  • no rule, documents checkedCalifornia sets no limit on how tall a fence at a house can be. Cities and counties write that in their zoning codes and the answer changes a lot from one town to the next. The one height in state law is the ten feet in the spite fence rule, and that only matters when the fence was put up to annoy a neighbor. It is not a building limit. Civ. Code 841California · Statute

Do I need a permit for a fence in Ontario?

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Ontario answers this in its own law. The words that do it are quoted below.

Ontario needs a building permit for a fence over three feet, whatever it is made of. Concrete block walls, block pilasters, chain link, wrought iron and wood all sit on the same line. That is the lowest fence permit threshold of any city read for this site, and it is half of what most cities use. A plain six foot back fence, which needs no permit at all in San Diego, Fremont, Riverside or Huntington Beach, needs one in Ontario.

Wood fences over 3 feet high

Building Permit FAQsCity of Ontario, Community Development, Building Department · Read 17 September 2026

3 ftheight at which any fence starts needing a building permit

Also on permits in Ontario

  • set in state lawCalifornia does not write its own building code from scratch. Section 17922 adopts Title 24 of the California Code of Regulations and requires it to ask for much the same things as the International Building Code and the International Residential Code, with state additions and cuts. So the permit rule for a fence starts out as outside code text that California then edits. Health & Saf. Code 17922California · Statute
  • set in state lawA California city or county can make the statewide building code stricter, but not quietly. Section 17958.7 makes the city council say in writing why each change is needed because of local weather, ground or land shape. That finding goes to the California Building Standards Commission, and the change does nothing until it is filed. The finding is a public record, which is why a local permit line can sit well below the statewide one. Health & Saf. Code 17958.7California · Statute

Pool fence requirements in Ontario

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California answers this in its own law. The words that do it are quoted below.

A pool fence in California stands at least sixty inches high. No more than two inches may be left between the ground and the bottom of it, and no gap in it may pass a four inch ball. The outside face has no handholds or footholds a child under five could climb. Gates open away from the pool and close and latch by themselves, with the latch set no lower than sixty inches above the ground.

This one is California law, not Ontario law. All California findings

An enclosure shall have all of the following characteristics: (a) Any access gates through the enclosure open away from the swimming pool, and are self-closing with a self-latching device placed no lower than 60 inches above the ground. (b) A minimum height of 60 inches. (c) A maximum vertical clearance from the ground to the bottom of the enclosure of two inches. (d) Gaps or voids, if any, do not allow passage of a sphere equal to or greater than four inches in diameter. (e) An outside surface free of protrusions, cavities, or other physical characteristics that would serve as handholds or footholds that could enable a child below the age of five years to climb over.

Health & Saf. Code 115923California Legislature · Read 13 September 2026

60 inminimum height of a pool enclosure

Spite fence laws in Ontario

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California answers this in its own law. The words that do it are quoted below.

A fence over ten feet tall in California is a private nuisance when it was put up or kept there to annoy the neighbor and the extra height serves no purpose. Height on its own is not enough. The case turns on proving why the fence is there. The rule covers anything built like a fence, not only a fence.

This one is California law, not Ontario law. All California findings

Any fence or other structure in the nature of a fence unnecessarily exceeding 10 feet in height maliciously erected or maintained for the purpose of annoying the owner or occupant of adjoining property is a private nuisance.

Civ. Code 841.4California Legislature · Read 13 September 2026

10 ftspite fence threshold, with malice required

How fence height is measured in Ontario

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Ontario answers this in its own law. The words that do it are quoted below.

Ontario uses two starting points in the same FAQ and the difference is deliberate. A fence is measured from grade, so the ground it stands on. A retaining wall is measured from the bottom of its footing, so the concrete under the ground counts as well. The reason is what each rule is worried about: a fence is about what somebody sees over, a retaining wall is about what is holding back the earth, and that job starts below the surface.

Concrete block walls over 3 feet high from grade

Building Permit FAQsCity of Ontario, Community Development, Building Department · Read 17 September 2026

Also on how height is measured in Ontario

  • left to the townCalifornia gives a fence height and never says what it is measured from. Civil Code section 841.4 makes a fence over ten feet a private nuisance when it is kept up to annoy a neighbor. It does not say whether the ten feet starts at bare dirt, at the finished yard, or at the high side of a slope. Government Code section 65850 is why the state stops there: it lets any county or city set the place, height and size of structures. So the number and the surface it starts from are both written into local zoning. Cal. Gov. Code 65850(c)(1)California · Zoning code

Fence rules for corner lots in Ontario

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California answers this in its own law. The words that do it are quoted below.

California writes no clear view triangle into state law. The Streets and Highways Code counts a fence as an encroachment once it stands in, under or over any part of a state highway right of way. Section 670 then makes putting one there without a written permit from the department a misdemeanor. That covers the public strip, not the corner of a private yard. Government Code section 65850 gives every city and county the power to set the height and place of structures, and that is where a corner triangle gets written in California.

This one is California law, not Ontario law. All California findings

“Encroachment” includes any tower, pole, pole line, pipe, pipe line, fence, billboard, stand or building, or any structure, object of any kind or character not particularly mentioned in this section, or special event, which is in, under, or over any portion of the highway.

Cal. Sts. & Hy. Code 660California Legislature · Read 13 September 2026

Retaining wall rules in Ontario

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Ontario answers this in its own law. The words that do it are quoted below.

A retaining wall in Ontario needs a permit above two feet, and the two feet runs from the bottom of the footing to the top of the wall rather than from the ground. Counting the buried part makes the threshold lower still in practice: a wall showing eighteen inches above the soil with a foot of footing under it is already over. San Jose uses the same two feet but measures from existing grade, so Ontario is the stricter of the two.

A permit is required for retaining walls over 2 ft. in height measured from the bottom of the footing to the top of the wall.

Building Permit FAQsCity of Ontario, Community Development, Building Department · Read 17 September 2026

2 ftretaining wall height from the bottom of the footing, before a permit is needed

Also on retaining walls in Ontario

  • left to the townCalifornia has no rule of its own in statute for a wall that holds back earth. The rule is in Title 24 of the California Code of Regulations, which section 17922 adopts by reference and requires to match the newest editions of a named list of outside codes, the International Building Code and the International Residential Code among them. The same section leaves setbacks, side yards, rear yards and property line rules entirely to cities and counties. Health & Saf. Code 17922(a)California · Statute

Fence materials allowed in Ontario

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Ontario answers this in its own law. The words that do it are quoted below.

The Ontario permit list names five things and holds them all to the same three feet: concrete block walls, block pilasters, chain link, open or screened wrought iron fences and gates, and wood. Naming pilasters separately matters, because Anaheim treats them as a place to gain height and Ontario treats them as another thing needing a permit. Nothing on the list gets extra room for being light or open.

Open or screened wrought iron fences and gates over 3 feet high

Building Permit FAQsCity of Ontario, Community Development, Building Department · Read 17 September 2026

Also on materials in Ontario

  • set in state lawCalifornia sets a wire standard for a lawful fence in grazing counties. A wire fence takes three tight barbed wires on solid posts set no more than a rod apart, with one wire at least four feet up. Any fence as strong and as tall as that one counts too. Cal. Food & Agric. Code 17121California · Statute

Livestock and boundary fence law in Ontario

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California answers this in its own law. The words that do it are quoted below.

California calls a fence lawful when it is strong enough to keep livestock from getting in or out. A wire fence gets real numbers: three tight barbed wires on posts set no more than one rod apart, with one of those wires at least four feet off the ground. Any other fence as tall, as strong and as good at holding animals counts too, and so does a cattle guard wide and deep enough to turn them.

This one is California law, not Ontario law. All California findings

No wire fence is a good and substantial fence within the meaning of this article unless it has three tightly stretched barbed wires securely fastened to posts of reasonable strength, firmly set in the ground not more than one rod apart, one of which wires shall be at least four feet above the surface of the ground.

Cal. Food & Agric. Code 17121California Legislature · Read 13 September 2026

4 ftheight of the top wire on a lawful wire fence

Also on agricultural fencing in Ontario

  • depends, see the pageCalifornia answers this one county by county. Section 17123 names Siskiyou, Lassen and Modoc, plus parts of Trinity and Shasta, as land used mainly for grazing. Section 17124 lets the board of supervisors of any county put the same label on the county or part of it. Where the label applies, the land has to be fully fenced before the person on it may take in a stray animal or hold it for payment. Cal. Food & Agric. Code 17122California · Statute

Documents behind this page

10 documents, of which 1 was published by Ontario itself. Each was read on the date shown.

  1. California LegislatureCalifornia Civil Code Section 841, Good Neighbor Fence Act of 2013Civ. Code 841 · Read 13 September 2026
  2. California LegislatureCalifornia Civil Code Section 841.4, spite fencesCiv. Code 841.4 · Read 13 September 2026
  3. City of Ontario, Community Development, Building DepartmentBuilding Permit FAQsRead 17 September 2026
  4. California LegislatureCalifornia Health and Safety Code Section 17922, adoption of building standardsHealth & Saf. Code 17922 · Read 13 September 2026
  5. California LegislatureCalifornia Health and Safety Code Section 17958.7, local modification of building standardsHealth & Saf. Code 17958.7 · Read 13 September 2026
  6. California LegislatureCalifornia Health and Safety Code Section 115923, enclosure requirementsHealth & Saf. Code 115923 · Read 13 September 2026
  7. California LegislatureCalifornia Government Code, Title 7, Division 1, Chapter 4, Article 2, Section 65850Cal. Gov. Code 65850(c)(1) · Read 13 September 2026
  8. California LegislatureCalifornia Streets and Highways Code, Division 1, Chapter 3, Section 660Cal. Sts. & Hy. Code 660 · Read 13 September 2026
  9. California LegislatureCalifornia Food and Agricultural Code, Division 9, Part 2, Chapter 3, Article 5Cal. Food & Agric. Code 17121 · Read 13 September 2026
  10. California LegislatureCalifornia Food and Agricultural Code, Division 9, Part 2, Chapter 3, Article 5Cal. Food & Agric. Code 17122 · Read 13 September 2026

What this page does not cover

A city ordinance is not the only rule that reaches a fence. The zoning district a parcel sits in can change the height allowed on it, and so can an overlay district, a recorded easement, a fire hazard severity zone or a coastal zone. A homeowner association can be stricter than the city and nothing in the municipal code will say so. None of those appear here.

The rules above are the ones Ontario publishes, plus the California rules that apply where the city sets none. Fence laws in California has the state layer in full.

This is general information drawn from published government documents. It is not legal advice, ordinances are amended, and the date beside each finding is the date the document was read. How findings are made · What the terms mean