A survey is a licensed professional's measured drawing of a property's legal boundaries, improvements, and encumbrances — the document that answers, with lines instead of arguments, where your land ends, what sits on it, and what rights others hold over it. The plat map is the neighborhood-scale drawing showing how the subdivision was divided into lots. Most buyers skim both at closing; the disputes that surveys would have prevented — the fence over the line, the neighbor's shed, the surprise drainage easement — are perennial fixtures of property litigation, and title insurance policies carry survey-related exceptions precisely because boundaries matter.
Here is how to read yours. (This article publishes information, not legal advice.)
The basic vocabulary
- Boundary lines and bearings: the property's edges, described in the metes-and-bounds tradition by compass bearings and distances (N 42°15'30" E, 125.40 feet) or by lot-and-block references to the recorded plat. The numbers are the law; the fence is not.
- Monuments: the physical markers — iron pins, concrete markers — found at corners. A found pin beats a remembered one.
- Improvements: the house, garage, driveway, well, septic, pool — drawn where they actually are, which is how you learn the garage sits two feet over the line.
- Setbacks: the drawn or noted distances from improvements to boundary lines — your first check against local zoning when planning an addition.
- Easements: rights others hold to use part of your land — utilities, drainage, access. Drawn as dashed lines with labels; the most consequential marks on the page.
Read it in this order
- Match the drawing to the deed's legal description — lot and block numbers, or metes and bounds; a survey of the wrong parcel is rare but not mythical.
- Walk the boundaries against reality: take the survey outside. Does the drawn fence sit on the line, inside it, or over it? Fences are frequently not on property lines; the survey is the truth and the neighbor's belief is not.
- Find every easement and ask what it entitles: a drainage easement may forbid fencing or building over a swale; a utility easement gives the power company the right to dig up a strip of your yard — landscaping there is done at your own risk.
- Check encroachments both directions: their shed on your land (your problem to tolerate or challenge, and a title issue if unrecorded) and your driveway on theirs (title insurance and negotiation territory).
- Look for the riparian or high-water line if water adjoins — the boundary of waterfront property is legally subtle, and the survey is where it shows.
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Types of surveys you may meet
| Type | Shows | Typical use |
|---|---|---|
| Boundary/lot survey | Lines, monuments, improvements | Standard purchase |
| Mortgage/ALTA survey | Boundary + easements, encroachments, detailed certification | Lenders, commercial, disputes |
| Plat of subdivision | How a tract became lots | New builds, land purchase |
| Topographic survey | Elevation and contours | Building design, drainage work |
When you need a new survey
Any purchase where boundaries are unclear or fences conflict; before building anything near a line (the $600 survey versus the $16,000 garage relocation); when selling land you subdivided; and when a neighbor's project approaches the line — the pre-construction conversation between surveyors is the cheapest dispute resolution mechanism in property law. Boundary disputes themselves follow quiet-title and adverse-possession doctrines that vary by state; if a disagreement survives one neighborly conversation, the next call is a real-estate attorney with the survey in hand, not a fence company.
FAQ
What is a property survey?
A licensed surveyor's measured drawing of a parcel's legal boundaries, monuments, improvements, and easements. It is the authoritative answer to where your property ends — fences and assumptions are not.
Does a fence mark the property line?
Frequently not. Surveys routinely find fences feet from the legal line. The boundary is defined by the deed and monumented corners; the fence is a structure that may encroach — check it against the survey before relying on it or building to it.
What is an easement on a survey?
A legal right for someone else to use part of your land — for utilities, drainage, or access — shown as labeled dashed lines. Easements can restrict fencing, building, and landscaping within them, and they run with the land, so read them before planning improvements.
For more context, read How to read a floor plan before you fall for the apartment.
For more context, read apartment tour checklist.
For more context, read What it takes to turn an office tower into apartments.