Here's what you should know about property line disputes and how to resolve them before listing your home for sale.

What are property lines?

Property lines are the legal and physical boundaries that define where a property begins and ends. Some property lines are clearly marked and others are invisible.

Knowing your property lines can help prevent encroachment, trespassing, and potential conflicts with neighbours when you make improvements such as installing a fence, landscaping, or building a garage.

Encroachment on real property is when one property owner violates the property rights of a neighbour.

It does not necessarily mean that the neighbours have a beef with each other. Many people are unaware that their garage, driveway, fence or even pool may have crossed the boundary line.

Often, property disputes come to light when remodelling or landscaping requires a survey to determine property lines. But disputes can also arise during the due diligence of purchasing a home.

Some neighbours may accept a minor issue, such as overgrown rhododendrons creeping over their property line, while others will seek an easement.

The difference between an encroachment and an easement is clear. An encroachment is an unauthorised use of property. An easement is consensual and gives one party the legal right to use a property for their personal needs.

In real estate, an easement might be the shared driveway you must use to access your garage, or the path in your yard that leads to the public beach (if you own beachfront property).

Easements are usually permanent and can be viewed as good, bad or ugly depending on how the buyer views them.

An easement for a driveway may not be a big deal. However, if the easement is with the seller's neighbour and ensures a view of the neighbour's lake, then the easement can be a deal breaker. This means that the buyer is not allowed to plant trees, add on to the property, or do anything that might block the view.

Even if you're perfectly content to let your neighbour's garage extend a foot inside your property line, the buyer probably won't. If there is an easement, such as a shared pavement to the beach, a buyer may consider it an invasion of privacy and remove your home from the list.

"For these reasons, if a buyer learns that a portion of their home or garage, fence, pool, trees or landscaping is located on a neighbour's property (and vice versa), they may rightly decide to give up all hope of purchasing that home in favour of a property that doesn't expose them to that risk," says Rees.

Sometimes boundary issues are discovered during the due diligence of buying or selling a property.

This happened to a home seller in Chicago who was unaware of a property boundary issue. The title company discovered that another entity owned part of the seller's property. The seller was the original homeowner and purchased the home directly from the developer, who purchased it from the City of Chicago.

Diane Vanna, a buyer's agent with Baird & Warner in Chicago, said the city still owns part of the property, including the location of the garage and a portion of the house's kitchen.

That oversight was never clarified when the seller took possession of the house in the late 1960s.

As a result, the closing was delayed for about two weeks while the issue was researched and a solution was proposed, Vanna said.

Ultimately, the title company decided that no one could make a claim on the property and insured the sale through a title policy.

How do I resolve a property line dispute?

Hire a surveyor: Even if you're sure you know exactly where the parameters of the property are, it's still a good idea to get an accurate description before you have an interested buyer to avoid surprises.

If a survey confirms an encroachment, but there is no recorded easement authorising the encroachment, both parties should try to informally negotiate an agreement, says Ries. Negotiate the details with your neighbours and ask a real estate lawyer to document the agreement.

SEEK LEGAL ADVICE: If you are unable to agree on boundaries, seek legal advice from a real estate attorney. This lawyer will help you understand all of your legal options and take appropriate action to protect your interests.

Alternatively, you can hire a professional mediator, who is usually less expensive than an attorney and will endeavour to resolve the dispute in an ADR manner.

File a lawsuit: Litigation should be the last resort for resolving property line disputes. Litigation is costly, time-consuming, and stressful. In addition, judicial intervention may delay the sale of your home for months or even years.