Who Can Claim Property Based on Adverse Possession in Washington?

To make sure that your land remains yours and that a neighbor can’t lay claim to a portion of it, it's wise to familiarize yourself with Washington's rules on adverse possession.

By , Attorney Benjamin N. Cardozo School of Law
Updated 7/13/2023

Many types of disputes can impact one's relationship with neighbors, but nothing represents a higher-stakes dispute than one over title to land. Whether you own an Arts and Crafts bungalow in Seattle or an undeveloped parcel in Olympia, your Evergreen State home is probably your most valuable asset, which you should do everything in your power to protect.

As a property owner in Washington, you likely have two or three neighbors whose land borders yours. Surprising though it might seem, those neighbors might be able to gain legal title to pieces of your property under a legal concept called adverse possession. And while less likely, an unknown trespasser could also squat on your land and develop the same type of claim to legal ownership.

To make sure that your land remains yours and that a neighbor can't lay claim to a portion of it, it's wise to familiarize yourself with Washington's rules on adverse possession. You yourself might also someday need to assert an adverse possession claim over land that you feel you've developed a right to use and want to continue using; especially if you learn that you've been paying property taxes on that land, despite the fact that it's not included in your formal deed.

How Adverse Possession Laws Work

Adverse possession is a legal concept that allows a trespasser—sometimes a stranger but more often a neighbor—to gain legal title over the land of a property owner. The concept developed in early Britain. The law's basic function is to achieve a fair result when one owner has neglected or forgotten about a piece of land while another has been using or caring for it for so long that to make that person leave would create hardship or unfairness.

Adverse possession in Washington is controlled by state statute, but also by the courts. Importantly, the burden of proof to establish a claim of adverse possession is on the trespasser. The legal holder of title is its presumed owner until the adverse possessor can meet that burden. In other words, the trespasser must do all the work of proving that a judge should give them ownership over the land.

Washington's Requirements for Adverse Possession

Both the statutes in Washington and state court decisions spell out the elements that a trespasser must establish in order to prove adverse possession. As in most states, adverse possession in Washington is established from the nature of a trespasser's possession and the length of time in possession of the land. A trespasser's possession must be:

  1. hostile (against the right of the true owner and without actual permission)
  2. actual (exercising control over the property)
  3. exclusive (in the possession of the trespasser alone, not shared with others)
  4. open and notorious (using the property as the real owner would, without hiding the occupancy, and perhaps adding structures or landscaping), and
  5. continuous and uninterrupted for the statutory period (which is normally 10 years in Washington, under Wash. Rev. Code Ann. § 4.16.020; though it reduces to 7 years if the trespasser had "color of title" and paid taxes on the land, as discussed below.)

For example, imagine that Mary and Samuel live next to one another in Olympia. No dividing fence or boundary exists between their yards. Samuel builds a series of beekeeping sheds that are actually on Mary's side of the property, covering about 14 square feet of earth. Mary doesn't say anything. Samuel tends to his bees and uses the sheds as if they were on his own land. He does this for ten years. Under the rubric described above, Samuel can probably establish that he "owns" the land on which he was encroaching. Mary could have stopped him by asking, over those ten years, that he remove his beekeeping structures, or sign a rental agreement in order to continue using them with her express permission. But Washington courts won't let her suddenly eject Samuel after having sat on her rights for ten years.

Additional Requirements for Claiming Adverse Possession of Washington Forestland

In addition to the usual adverse possession requirements, someone attempting to claim possession of forestland in Washington State must show that they've made or erected substantial improvements, which remained entirely or partially on the land for at least ten years. (See RCW § 7.28.085.)

"Substantial improvement" means a permanent or semi-permanent structure or enclosure that cost at least $50,000 to construct. Also, this section can't be used against a landowner whose area of forestland is less than 20 acres.

Trespasser's Intent Irrelevant in Washington

The doctrine of adverse possession protects someone who has honestly entered and held possession in the belief that the land is their own, as well as one who knowingly appropriates others' land for the specific purpose of acquiring title. In other words, in Washington, there is no requirement that the entry and continued possession of the property be done with knowing or intentional hostility.

Rather, any entry and possession for the required ten years that is exclusive, continuous, hostile, actual, and open—even if under a mistaken claim of title—is sufficient to support a claim of title by adverse possession. In our example above, it doesn't matter whether Samuel built the beekeeping sheds knowing that he was on Mary's land, or whether he built them mistakenly thinking he was on his own land. His intent has no bearing on his eventual claim for title under adverse possession.

Shorter Limitations Period When Property Is Held Under Color of Title

As discussed above, Washington State generally requires a ten-year period of occupying property in order for a trespasser to gain title under Wash. Rev. Code Ann. § 4.16.020. One exception to this is when the property in question is held under color of title, per Wash. Rev. Code Ann. § 7.28.050.

"Color of title" means that there is a legally filed document that gives the appearance of actual legal title, but that this document turns out not to be legally valid (likely due to a mistake). The person must also have paid taxes on the property in order to assert a claim (Wash. Rev. Code Ann. section 7.28.070).

Protect Your Washington Property With an Action to Quiet Title

What should you do if you spot a trespasser or a neighbor encroaching on your land? Chances are, it's an innocent mistake. Your first step should be to nicely ask the person to move.

If that doesn't work, you might need to consult a lawyer. The lawyer might be able to find exceptions in the law that would defeat a claimant's effort to assert title over your land. The lawyer might also suggest bringing an action to quiet title—a legal method for determining who owns a piece of land. In an action to quiet title, you're asking a Washington Superior Court judge to issue an order declaring that you, and not the trespasser, are the true owner of the land.

This type of order is particularly helpful if you are seeking to sell your property, and need to reassure potential buyers about the extent of your ownership. ("Who's that woman using that shed there?" might be one of the first questions from a prospective buyer's mouth.)

No Claims Against Washington's Government Land

Land held by Washington's government entities are broadly immune from adverse possession actions. In other words, title to public lands generally can't be acquired by adverse possession as against the state. So if you live next to Olympic National Park, you won't be able to expand your backyard by planting a garden and waiting ten years or more. Washington will retain legal ownership.

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