Why It Matters
A plat is an official, recorded map laying out the boundaries and divisions of a tract of land. Municipalities require plats whenever land is subdivided, and the map becomes part of the public record. Investors review plats to understand exactly what they're buying — and what restrictions or encumbrances come with it.
At a Glance
- Official recorded map showing lot lines, dimensions, and parcel numbers
- Required whenever land is formally subdivided
- Filed with the county recorder or register of deeds
- Shows easements, rights-of-way, and setback lines
- Lot numbers on a plat correspond to legal descriptions in deeds
- A "replat" amends or combines existing platted lots
- Plats are public records — free to access online or at the courthouse
- Does not replace a current boundary survey
- "Vacating" a plat removes it from the record (rare)
- Discrepancies between a plat and a physical survey must be resolved before closing
How It Works
When a developer divides a parcel into individual lots, the government requires a formal plat map before any lot can be sold. A licensed surveyor prepares it; a local planning authority approves it. Once recorded, it becomes a permanent public document.
What a plat map shows:
- Lot boundaries and dimensions — legal shape and size of each parcel, with bearings and distances along every boundary line
- Lot numbers — assigned numbers that tie to the legal description in deeds and title documents
- Easements — strips of land reserved for utilities, drainage, or access; shown as dashed lines or shaded areas
- Rights-of-way — land dedicated to public roads, sidewalks, or alleys
- Setback lines — minimum distances structures must sit from lot lines
- Monuments — iron pins or concrete markers placed by the surveyor
Subdivision plats vs. replats: A subdivision plat creates new lots from raw land. A replat modifies an existing subdivision — combining adjacent lots, adjusting a boundary, or correcting an error.
How to find a plat: Every recorded plat is indexed at the county recorder or assessor's office. Most counties post plat maps online through their GIS portal — search by address or parcel number.
How investors use plats: Pull the plat to verify lot dimensions, confirm existing easements, and check whether rights-of-way cut through usable land. Pair it with a title search and a review of recorded easements for a complete picture of what limitations come with the property.
Real-World Example
Lisa found a duplex on a large corner lot in a midwestern city. The listing advertised the backyard as "perfect for an ADU," and she underwrote the deal assuming she could add a detached unit.
Before ordering an inspection, she pulled the plat from the county GIS portal. It showed a 15-foot utility easement running diagonally across the rear lot — exactly where she planned to build. The municipal water authority owned it and prohibited permanent structures within its boundaries.
The ADU plan was dead. Lisa renegotiated a lower price reflecting the true buildable area and restructured her offer around the duplex income alone. Twenty minutes with the plat saved her from a costly assumption that was never legal to execute.
Pros & Cons
- Reveals easements, rights-of-way, and setback requirements not visible during a walkthrough
- Confirms legal lot dimensions, which may differ from county tax records
- Identifies lot numbers that tie directly to the legal description in the deed
- Freely available as a public record
- Can be decades old — may not reflect subsequent replats or vacations
- Requires familiarity with surveying notation to read accurately
- Does not show current physical conditions — fences, encroachments, or structures won't appear
- Doesn't replace a current boundary survey
- Easements recorded in separate instruments won't appear on the map
Watch Out
Easements not visible during inspection: A utility easement under a lawn looks like usable land. Cross-reference the plat with Schedule B of the title commitment, which lists all recorded easements.
Vacation of plats: When a plat is formally vacated, the lot lines it created are extinguished. If a property's legal description references a vacated plat, the chain of title is complicated and title insurance may be hard to obtain.
Discrepancies with a survey: Older plats may contain errors corrected by subsequent surveys. If the deed references the plat but physical pins don't match, a boundary dispute follows. Flag any discrepancy to a real estate attorney before closing.
Replats you don't know about: If a prior owner replatted the property, the original plat may be superseded. Always confirm you're looking at the most current recorded version.
Ask an Investor
The Takeaway
A plat is one of the fastest, cheapest due diligence steps available. It reveals legal boundaries, easements, and restrictions before any money changes hands. Skipping it — especially on properties with development potential — is how investors end up with land they can't legally use the way they planned.