A Sammamish property survey is the one document that shows where your lot actually ends. The listing photos, the fence and the lines on a county map all suggest a boundary, but none of them establish one. On the Sammamish Plateau, where lots run larger, trees run taller and some plats date back more than a century, that difference can matter.

This guide covers what buyers can find on their own before an offer, what title insurance does and does not cover on boundaries, when a new survey is worth ordering, and how fences, trees and encroachments fit in. We checked every rule and record source below on October 2, 2026. It is a process overview, not legal or surveying advice. A licensed land surveyor and a real estate attorney are the right people for any specific line.

Why a Sammamish Property Survey Matters on the Plateau

Many Sammamish homes sit on lots where the boundary is hard to see. Wooded edges, slopes, shared driveways and private roads all blur where one parcel stops and the next begins. Some neighborhoods were platted long before the city incorporated in 1999. The Plat of Inglewood, for example, was recorded in 1889, and our Inglewood Hill neighborhood tour covers how that history still shows up today.

Most boundary questions come up for practical reasons. A buyer wants to add a fence, a shop or an accessory building. A neighbor's shed looks close to the line. A row of mature trees straddles the edge of the lot. If you are buying acreage, our guide to Sammamish horse properties and acreage covers why land use plans make the exact line more important.

What You Can Look Up Before Ordering a Sammamish Property Survey

You can do a good deal of homework for free before you hire anyone.

1. The county parcel map. The King County Parcel Viewer shows parcel outlines, but the county states that lot lines are approximate, created for assessment purposes and not for legal use. Treat it as a starting point, not an answer.
2. The recorded plat. The King County Recorder's Office keeps digital images of plats from 1870 to the present and short plats from 1977. The plat shows the lot's dimensions as created, plus easements and notes recorded with it.
3. Prior recorded surveys. The same office has recorded private surveys from 1973 on, along with boundary line adjustment maps from 1981. Search the county's Landmark records system using the Legal search type, then Advanced Legal.
4. The seller's disclosure. Washington's seller disclosure statement asks whether there are "any encroachments, boundary agreements, or boundary disputes" and whether there is "a boundary survey for the property," under RCW 64.06.020. Read those answers closely and ask for a copy of any survey the seller has.

One caution: not every survey ends up in the public record. Under RCW 58.09.090, a surveyor who retraces a platted lot with its monuments in place and finds no discrepancy is not required to record a new survey. An empty search does not always mean no one has surveyed the lot.

Title Insurance and Your Sammamish Property Survey

Buyers often assume title insurance settles the boundary question. It usually does not, at least not in its basic form. The Washington Office of the Insurance Commissioner describes an owner's policy as protection against problems such as liens, forgeries and errors in recorded documents, and it advises buyers to ask their title provider about any exclusions.

Boundary problems are a common gap. A comparison published by WFG National Title lists encroachment coverage, such as your structures over the line or a neighbor's structures on your land, under the expanded homeowner's policy, not the standard owner's policy. Some of those items carry a deductible and a dollar cap, and some exclude boundary walls and fences.

The takeaway is simple. When your title commitment arrives, ask the title officer which survey-related matters are excepted, what extended or expanded coverage would add, and whether that coverage requires a survey.

When to Order a New Sammamish Property Survey

A boundary survey is a licensed land surveyor locating your lot lines on the ground and marking the corners. In Washington, surveyors are licensed through the Board of Registration for Professional Engineers and Land Surveyors, and you can confirm a license with the Department of Licensing lookup.

Situations where buyers commonly consider one include:

• You plan to build a fence, addition, shop or accessory dwelling near a lot line.
• A neighbor's structure, driveway or landscaping appears to cross onto the lot.
• The seller marked a "Yes" or "Don't know" on the encroachment question.
• The lot is large, wooded, steep or irregular, and no recorded survey exists.
• Access runs over a private road or easement. Our guide to buying a Sammamish home on a private road covers the recorded documents to look for.

Timing is the hard part. A survey ordered after mutual acceptance has to fit inside your contract deadlines, so talk with your agent about how to build in time before you write the offer. Our explainer on how buyer agent agreements work in Sammamish covers what your agent does for you during that window.

Fences, Trees and Encroachments

Fences. A fence is not a property line. It may sit on the line, inside it or over it. The City of Sammamish's residential fence handout allows six-foot fences in side and rear yards and four feet in front yards. A fence up to eight feet tall and 32 feet long along a shared side or rear line needs a permit and a recorded agreement with the neighbor. The city's lot lines handout explains which line counts as front, side or rear, including on lots reached by a private street. Handouts are illustrative, so confirm the current code before you build.

Trees. On wooded Plateau lots, knowing the line matters before anyone cuts. Under RCW 64.12.030, cutting or injuring a tree on someone else's land without lawful authority can bring treble damages. The city's own tree rules are covered in our guide to trees, slopes and what you can build on a Sammamish lot.

Boundary agreements. If neighbors cannot find a line from the public record, or disagree about it, RCW 58.04.007 lets them fix it by a signed, recorded written agreement that includes a survey map and runs with the land. If they cannot agree, either can ask the superior court to establish the line under RCW 58.04.020, and the court may order mediation first.

Adverse Possession, Stated Carefully

Buyers sometimes hear that a neighbor who uses a strip of land long enough can claim it. Washington's ten-year limit on lawsuits to recover real property, RCW 4.16.020, is the clock behind that idea. A separate statute, RCW 7.28.070, sets a seven-year path for someone in open possession under a good-faith paper title who also paid all the taxes. Under RCW 7.28.083, a court can require a successful claimant to reimburse taxes the owner paid and can award attorneys' fees.

Whether any claim exists depends on facts a court weighs, so this is attorney territory. For a buyer, the practical point is narrower: an old fence or hedge that does not match the recorded line is a reason to ask questions before closing, not after.

Frequently Asked Questions About a Sammamish Property Survey