Plat
A plat is a recorded survey map dividing land into numbered lots and blocks. It creates the legal descriptions by which those lots are afterwards conveyed.
What it does#
Creates lots. After recording, land that was one parcel is a series of numbered lots, each with its own description: lot 7, block 3, of the named subdivision.
Dedicates streets and easements. Roads are dedicated to public use; drainage and utility easements are laid out, usually along lot lines.
Establishes dimensions and monuments. It is a survey document, and the measurements on it are what determine where boundaries actually run.
Recording is the operative act#
A plat under review is a proposal. The lots do not exist.
Recording is what creates them, and it is why subdivision approval processes end with a final plat being recorded rather than merely approved.
Buyers occasionally contract for a lot in a subdivision that has not yet been platted. That is a contract for something that does not exist yet, and the timeline for it coming into existence is not within the seller's sole control.
Reading one#
Worth doing before building anything.
Easements are the item most often overlooked. A drainage and utility easement running along the rear and side lot lines is standard and it constrains where a structure, a fence or a shed can go — independently of the zoning setbacks, which are a separate limit.
Dimensions on the plat govern over an assumption from a fence or a driveway.
Dedications show what is public and what is not.
Changing one#
A replat redivides platted land, requiring the same approval process again.
A vacation removes a dedicated street or easement, and it requires the approval of the jurisdiction and, in some cases, of affected owners.
Neither is something an owner does unilaterally, because a plat created rights in everybody who bought a lot relying on it.
Where it matters in distressed property#
Older plats in Minnesota cities frequently show lots far narrower than current zoning permits — 25- and 30-foot lots platted in the 1880s. Several adjoining lots under one ownership are usually treated as a single buildable parcel, and separating them again is generally not permitted.
That matters when a tax-forfeited or foreclosed property covers two or three platted lots. Whether they can be sold separately depends on the ordinance, not on the plat, and the answer is usually no.
Unplatted land described by metes and bounds or by the public land survey system carries a different set of questions, principally whether the parcel was lawfully created at all.