A plat of survey is a scaled drawing of a specific piece of land, prepared and sealed by a licensed professional land surveyor, that shows the property’s exact boundaries, dimensions, structures, and legal constraints. It serves as both a legal record and a working map of what you own, where it ends, and what sits on it. You need one any time a lender, title company, building department, or neighbor needs certainty about where your lines fall: buying, selling, building, refinancing, subdividing, or settling a boundary dispute.
What a Plat Actually Shows
A plat packs a lot into one document. The boundary lines are drawn to scale, each labeled with a bearing (compass direction) and distance, and the total acreage or square footage appears on the face of the drawing. That tells you precisely how much land the parcel contains.
Physical features sit on the same drawing. Buildings, driveways, fences, walls, and other structures are plotted in relation to the boundary lines, which is how you learn whether anything sits too close to a line or crosses onto a neighbor’s land. Streams, tree lines, and significant changes in elevation usually appear as well.
The plat also maps the legal constraints on how you can use the land. Easements, meaning areas where someone else has a right to access or use part of your property (utility corridors, shared driveways), are drawn and labeled. Setback lines show how far from each property line local zoning allows you to build. If a structure crosses a boundary line, the plat flags it as an encroachment.
The Legal Description
Every plat includes or references a legal description, and the format depends on how the land was originally divided. Subdivided lots use a lot-and-block description: “Lot 54, Block 3, Chalet Estates.” Rural or irregular parcels use metes and bounds, tracing the outline from a fixed starting point through a series of bearings and distances until the description closes back on itself. If the deed description doesn’t match what the surveyor measures on the ground, that discrepancy shows up on the plat and has to be resolved before a sale or construction project moves forward.
Corner Markers on the Ground
When the surveyor finishes fieldwork, they set or locate physical markers at each corner. These are usually metal rods or iron pipes driven into the ground, sometimes capped with colored plastic stamped with the surveyor’s license number. Older properties may have hollow iron pipes or plain rebar; newer surveys often use rebar set in a small concrete collar. Markers are typically buried a few inches below the surface, so you shouldn’t expect to spot them without digging. The plat identifies each one by type and location, which lets you verify boundaries on the ground years later.
Plat of Survey vs. Subdivision Plat
People use “plat” to mean two different things, and the distinction matters. A plat of survey (also called a boundary survey) depicts a single parcel or a small group of lots and shows existing conditions, including buildings, fences, and encroachments. A property owner typically commissions it for a specific transaction or project, and it may or may not be recorded with the county.
A subdivision plat is different. It’s a recorded map a developer files when dividing a larger tract into individual lots, showing proposed lot lines, streets, utility easements, and common areas for an entire development. Subdivision plats go through municipal approval and become part of the public record. The lot-and-block description on your deed traces back to that recorded subdivision plat, but the subdivision plat won’t tell you where your fence actually sits or whether the neighbor’s shed is two feet over the line. For that, you need your own plat of survey.
When You Need One
A handful of situations make a survey practically unavoidable, and several more make it a smart precaution.
- Buying or selling property. Buyers want to know what they’re purchasing, and lenders want confirmation that the land matches the legal description in the deed.
- Building or adding on. Most local building departments require a survey before issuing a permit for new construction, additions, or large accessory structures like detached garages. The permit office uses it to verify setbacks and easement clearances.
- Boundary disputes. If you and a neighbor disagree about where the line falls, a survey by a licensed professional is the only way to settle it with legal authority. Fences, hedges, and “where we’ve always mowed” aren’t boundary evidence.
- Refinancing. Lenders sometimes require a current survey when refinancing, particularly on commercial properties or when the existing survey is old enough that conditions may have changed.
- Subdividing or combining parcels. Splitting one lot into two, or merging several into one, requires a new plat showing the proposed layout, which must be approved by the local planning authority and recorded.
- Flood zone work. Properties in or near a Special Flood Hazard Area often need an elevation certificate in addition to a boundary survey. A licensed surveyor prepares both, but they’re separate documents.
The Survey Exception on Your Title Policy
Title insurance policies contain a standard “survey exception” that excludes coverage for problems a survey would have revealed: encroachments, boundary overlaps, and unrecorded easements visible on the ground. In plain terms, if you skip the survey and a neighbor’s garage turns out to be on your land, your title policy won’t cover you.
When you give the title company a current survey, the insurer replaces that broad exception with specific, itemized exceptions for whatever the survey actually found. A clean survey gets you broader protection. For commercial transactions, title insurers almost always require an ALTA/NSPS survey before they’ll remove the exception and issue expanded coverage. For residential purchases, the requirements vary by lender and title company, but having a survey in hand gives you leverage to negotiate better coverage.
When an ALTA Survey Comes In
An ALTA/NSPS survey is the most comprehensive type of property survey, developed jointly by the American Land Title Association and the National Society of Professional Surveyors. It’s a boundary survey with significantly more detail, designed for lenders, title companies, and attorneys in commercial deals.
Beyond standard boundary and improvement locations, an ALTA survey cross-references every survey-related exception on the title commitment, including utility easements, access easements, and other recorded encumbrances, and plots each on the map. The surveyor signs a certification confirming the work meets current ALTA/NSPS standards.
Lenders typically require ALTA surveys for commercial acquisitions, refinances, and development projects. Residential buyers don’t usually need one unless the property is unusually complex or the lender insists. The extra detail costs more: ALTA surveys commonly run two to three times the price of a standard boundary survey.
Who Can Prepare One
Only a licensed professional land surveyor can produce a plat that carries legal weight. The licensing path is demanding. Many states require a four-year degree in surveying or a closely related field, though some accept a two-year degree with additional experience. Candidates then pass the Fundamentals of Surveying exam, work under a licensed surveyor for about four years, and sit for the Principles and Practice of Surveying exam. Both are administered by the National Council of Examiners for Engineering and Surveying. Only after passing both exams and meeting the state’s experience requirements can a surveyor sign and seal plats that courts and lenders will accept.
When you hire one, you’re paying for research into existing deeds and recorded plats at the county office, fieldwork with GPS and total station equipment, reconciliation of what’s on the ground with the legal record, and a sealed document. Relying on an unlicensed person or an informal sketch can cost far more later if a boundary problem surfaces.
How to Get a Plat of Survey
Check for an Existing One First
Before commissioning a new survey, see whether one already exists. Plats are often filed with the county recorder’s office or the local planning department, and many counties offer online access through GIS portals or document search tools. Your title company may have a survey from a previous transaction on file. If you’re buying, ask the seller for a copy from when they purchased the property.
One warning about county GIS maps: they aren’t surveys. Every county GIS system carries a disclaimer that the data is informational and wasn’t prepared for legal, engineering, or surveying purposes. GIS parcel lines can be off by several feet, and courts will not accept a GIS map as evidence of a property boundary. GIS is useful for general orientation and tax assessment, not for proving where your line falls.
Hiring a Surveyor
If no usable survey exists, or the one on file is too old to reflect current conditions, hire a licensed surveyor. Get quotes from two or three firms, because pricing depends on the property’s size, shape, terrain, tree cover, and the condition of the existing title records. A straightforward rectangular lot in a recorded subdivision is much cheaper than an irregular rural parcel with ambiguous deed descriptions.
For a standard residential boundary survey, expect to pay roughly $1,200 to $5,500. ALTA surveys for commercial properties typically run $2,500 to $10,000 or more. Turnaround for a residential boundary survey is usually one to three weeks, though complex projects or busy seasons can stretch to several months. If you need the survey for a closing, start early. Surveyors get backed up in spring and summer, and a rushed timeline often means a rush fee.
How Long a Plat Stays Reliable
A plat of survey doesn’t technically expire, but its usefulness fades as conditions change. If you or your neighbors have built anything since the survey date, if local zoning has been updated, or if erosion or flooding has altered the landscape, the survey no longer reflects reality. Most lenders and title companies want a survey no more than a few years old, and some require one performed within 90 days of closing.
Even if nobody is demanding a new one, updating your survey before a major project is smart. An outdated plat showing a 10-foot setback won’t protect you if a fence or addition has since cut into that clearance. If conditions on the ground have changed, order an updated survey.
When the Survey Finds a Problem
Surveys exist to surface problems before they become expensive. The two most common findings are encroachments and easement conflicts.
If a neighbor’s structure (a fence, shed, or driveway) crosses onto your property, you have options. The simplest is talking to the neighbor and working out a solution: they remove the encroachment, you grant them a written license to keep it in place, or you sell them the affected strip. Get the agreement in writing. Ignoring an encroachment long enough can give the neighbor a legal claim through adverse possession or a prescriptive easement. If you later sell, you’ll also need to disclose known encroachments to the buyer.
If you can’t resolve it informally, you may need to go to court, typically through a quiet title action to confirm ownership and, if necessary, an ejectment action to require removal of the encroaching structure. These cases aren’t fast or cheap, which is why getting a survey before you close is so much better than finding the problem afterward.
If the Surveyor Got It Wrong
If you believe the survey itself contains an error, start by getting a second survey from an independent firm to confirm the discrepancy. Licensed surveyors carry professional liability insurance (errors and omissions coverage), and if the original survey was materially wrong, you may have a claim for damages. Every state sets its own statute of limitations for these claims, and many states also impose a statute of repose that creates an absolute deadline regardless of when you discovered the mistake. Act quickly; these windows can be shorter than you’d expect. Check your title insurance policy as well, since some include coverage for survey-related issues. A real estate attorney can help you decide whether to pursue the surveyor, the title insurer, or both.