It usually starts innocently. You decide it's finally time to put up a fence, for the dog, the kids, a little privacy. You eyeball where you think the property line is, sink the posts on a Saturday, and feel pretty good about it. Then a few months later your neighbor knocks on the door with a survey showing your fence is two feet onto their land.
I've seen this scenario more times than you'd think, and it's one of the most avoidable disputes in real estate. A fence in the wrong spot can cost you the price of tearing it down and rebuilding, strain a relationship with someone who lives right next to you, and in the worst cases, raise questions about who actually owns that strip of land. Let me walk you through how to do this right.
You don't actually know where the line is
Here's the uncomfortable truth: most people don't know exactly where their property line runs. That old fence, the row of bushes, the edge of the driveway, none of those are reliable. They're just where things ended up over the years.
The only way to know for sure is a survey by a licensed Illinois land surveyor. Spending a few hundred dollars on a survey before you build is a bargain compared to tearing out a fence later. A survey also tells you where any easements sit, and that matters more than people realize.
Watch out for easements
An easement is someone else's right to use part of your property for a specific purpose, a utility line, a shared driveway, a drainage path. They're often recorded with the deed and easy to forget about.
Build a fence across a utility easement and the utility company may have every right to tear it down to get at their lines, at your expense, with no obligation to put it back the way it was. Before you set a single post, find out what easements cross your land. A survey and a look at your title will usually surface them.
The Illinois Fence Act and shared boundaries
Illinois has a Fence Act that's been on the books a long time, and it can come into play when a fence sits on the boundary between two properties, particularly in rural and agricultural settings. The general idea is that adjoining owners may share responsibility for a division fence, and there are mechanisms for sorting out who builds and maintains what.
For a typical suburban backyard fence the Fence Act may not drive the analysis, but the underlying lesson holds: a fence on a shared line is rarely just your business. The neighbor has interests too, and getting their input and agreement up front prevents a lot of grief.
Encroachment and adverse possession: the real risk
This is the part that gets people's attention. If a fence sits on the wrong side of the line, you've got an encroachment, and over time encroachments can ripen into bigger problems.
Illinois recognizes adverse possession, a doctrine where someone who openly uses another person's land in the right way for a long enough period can, under specific conditions, end up with a legal claim to it. The requirements are demanding and it doesn't happen overnight, but the principle should make you careful. If your neighbor's fence has been sitting on your land for years and you never said anything, you may be setting up a future claim against your own property. The reverse is true too.
The practical takeaway: encroachments don't fix themselves, and ignoring one can quietly cost you land. When you spot a fence or structure over the line, address it sooner rather than later, often with a simple written agreement or a corrected boundary.
The mistakes I see most
A few patterns come up again and again:
- Building off memory. Assuming the old fence or hedge marks the true line. It usually doesn't.
- Skipping the survey. Saving a few hundred dollars now and spending thousands later.
- Not talking to the neighbor. A five-minute conversation before you build prevents most fence disputes outright.
- Ignoring easements. Putting a permanent structure where someone else has a recorded right to dig.
- Letting an encroachment slide. Saying nothing for years, then being surprised when it becomes a legal issue.
Build it once, build it right
A fence should make your life easier, not turn into a lawsuit with the people next door. Before you build, get a survey, check for easements, talk to your neighbor, and put any boundary understanding in writing. That handful of steps is far cheaper than redoing the project or fighting over a strip of land.
If you're not sure where your line is, you've hit an encroachment, or a neighbor's project is creeping onto your property, it's worth a conversation before it escalates. You can learn more about how we help with these issues on our Real Estate page, and if a boundary problem ever overlaps with a rental property, our Landlord–Tenant page may be useful too.
A little care up front keeps a good fence from becoming a bad memory.