The Short Answer
Illinois law does not require a survey before you build a fence on residential property. But not having one is a gamble. A fence placed even a few inches over the line can result in forced removal, neighbor disputes, and legal costs that far exceed the price of a survey.
What Illinois Law Says About Fences
The Illinois Fence Act (765 ILCS 130/) is the primary state law governing fences. It focuses on partition fences, meaning fences along shared boundary lines between adjoining properties, mostly in agricultural contexts. The Act outlines how costs for shared fences can be divided and the obligations of each neighbor to maintain their portion.
What the Illinois Fence Act does not do is require a survey before any fence is built. It also does not override local ordinances. For most residential fence projects in Illinois, the rules that matter most come from your city, village, or county code, not from state law.
When Local Permits Require a Survey
Most Illinois municipalities require a permit to build a fence. When you apply, many jurisdictions ask for a site plan or survey showing the fence location relative to your property line. In those cases, a survey is effectively required by the permitting process, even though state law does not mandate it directly.
How this plays out varies by jurisdiction:
- Chicago and many Cook County suburbs require a survey or certified site plan showing fence placement and setback distances.
- Smaller downstate municipalities may accept a sketch with approximate measurements, but some require a licensed survey for fences near property lines.
- Unincorporated county areas have their own rules, often less strict than municipal codes but still worth checking before you start.
Call your local building department or check their website before assuming you can proceed without a survey. A stop-work order after the fence is partially installed costs far more than a survey would have.
Why You Should Get a Survey Even When It Is Not Required
The most common and expensive fence mistake is placing the fence on the wrong side of the property line. Here is why it happens more often than owners expect:
- Corner markers are often buried, missing, or displaced over time by construction, landscaping, or frost heave.
- Property lines in older neighborhoods frequently do not run parallel to streets, sidewalks, or existing fences.
- A neighbor's existing fence may itself be out of position, giving you a false reference point.
- County GIS parcel maps have measurement errors that can place a line several feet from its true location.
If your fence encroaches on a neighbor's property, Illinois law does not provide a forgiveness buffer for accidental placement. You bear the cost to remove and relocate the fence.
Illinois Adverse Possession and Fences
Some property owners assume that if a fence has been in a certain location for years, it creates a legal boundary. That is not how Illinois law works. Adverse possession in Illinois requires 20 continuous years of open, actual, hostile, and exclusive possession of the land in question. A fence placed by mistake and left in place for five or ten years does not establish any property rights. Only the 20-year threshold, if met, can change the legal boundary, and even then it requires a court judgment, not just the passage of time.
Fence Height and Setback Rules in Illinois
Even when you know exactly where your property line sits, local rules may prevent you from placing the fence directly on that line. Setback requirements and height limits vary by municipality:
Height Limits
Illinois has no statewide fence height limit for residential property. Local codes typically cap rear and side yard fences at six feet and front yard fences at four feet. Some municipalities allow taller privacy fences or require neighbor consent for fences above a certain height. Check your local code before purchasing materials.
Setback Requirements
A setback is the required distance between your fence and the property line. Rules vary significantly:
- Many Illinois municipalities allow fences directly on the rear and side property line.
- Front yard fences often have setback requirements ranging from one to three feet inside the property line.
- Corner lots frequently have additional setback rules to maintain sight lines at intersections.
- Properties near drainage easements, floodplains, or utility corridors may have additional restrictions.
You need to know both where your property line sits and what setbacks apply in your zoning district before you can correctly place a fence.
Shared Fences and Neighbor Cost Splitting
Under the Illinois Fence Act, neighbors who share a boundary fence may have mutual obligations for its maintenance and repair. In agricultural areas, the Act provides a process for determining each owner's share of partition fence costs. In residential areas, these provisions apply less often, and any cost-sharing arrangement usually comes from a private agreement between neighbors rather than from the statute automatically.
If you and a neighbor plan to share fence costs, get a survey done first to confirm the line. Then put any agreement in writing. A survey drawing becomes the evidence if the agreement ever needs to be enforced.
How a Boundary Survey Works for a Fence Project
The process is straightforward and typically takes one to three weeks from your first call to completion:
- Contact a licensed Illinois Professional Land Surveyor and provide the property address and parcel ID number.
- The surveyor researches the recorded plat, your deed, and neighboring parcel records at the county recorder's office.
- A field crew locates or sets corner monuments, typically iron pins driven at each corner of the property.
- A certified survey drawing is produced showing boundaries, dimensions, and corner locations.
- Corner markers are visible in the field, giving your fence installer clear reference points.
Some surveyors will stake the fence line itself, not just the corners, for an additional fee. On longer fence runs, this makes layout much more accurate and reduces the risk of gradual drift.
What a Survey Costs vs. What an Encroachment Costs
A residential boundary survey in Illinois typically runs:
- Downstate Illinois: $400 to $900 for a standard platted lot
- Chicago metro area: $600 to $1,500 depending on lot complexity
- Rural or acreage parcels: $800 to $2,000 or more
Compare that to the cost of removing and reinstalling a 150-foot privacy fence, which can run $2,500 to $6,000 or more including labor and materials. A survey is the cheaper option every time an encroachment is discovered.
Steps Before You Call a Surveyor
- Find your parcel identification number (PIN) on the county assessor's website. This speeds up the surveyor's quote process.
- Check whether a survey was done at your purchase closing. If it is recent and includes corner markers, it may still be usable.
- Review your local code for fence height, setback, and permit requirements before the survey is complete.
- Get quotes from at least two licensed Illinois PLS professionals before hiring.
Ready to find a licensed Illinois surveyor for your fence project? Search the Illinois land surveyor directory to find professionals in your area and get quotes before you break ground.