How Property Lines Are Defined in Louisiana
In Louisiana, property boundaries are defined by the legal description in your deed, called a notarial act or act of sale. That description may reference a recorded plat, use metes and bounds measurements, or, for older properties in river parishes, describe the lot using historic arpent measurements. The legal description is the authoritative record. Physical features like fences, walls, or hedges mark where someone built something, not necessarily where the legal line runs.
Finding your property lines accurately means working from the legal record, not from what you can see on the ground. This section walks through the available methods, from free online tools to the only method that produces a legally binding result.
Start with Your Act of Sale (Notarial Act)
The first place to look is your act of sale, the document you received when you bought the property. In Louisiana, property is transferred through a notarial act prepared by a notary (who in Louisiana is almost always a licensed attorney). The act of sale contains a legal description of the property: the street address, the lot and block number from a recorded subdivision plat, or a metes and bounds description giving the distances and directions of each boundary line.
If your property was subdivided from a larger tract in the 20th century, the legal description likely references a recorded plat by name and file number. That plat is on file at the parish courthouse and shows the lot dimensions as they were laid out at the time of subdivision. If the description uses metes and bounds with courses and distances, those measurements are what a surveyor would use to set physical corners.
If your property is in a river parish or an area settled during the French or Spanish colonial periods, the description may use arpent measurements. An arpent of front and depth means the lot has a certain number of arpents of frontage on the road or waterway, running back a certain number of arpents. This is a precise measurement, but it requires translation into modern units and coordinates by a licensed surveyor.
Parish Assessor Parcel Maps
Every parish in Louisiana has an assessor's office that maintains property records including parcel maps. Most Louisiana parish assessors now provide online access to parcel data and GIS maps. These tools let you look up your property by address or parcel number and see an approximate representation of your lot shape and its relationship to neighboring parcels.
Parish assessor parcel maps are useful for getting a general picture, but they come with a critical limitation: they are not surveys. They are compiled from deed records and are drawn to approximate scale. The line you see on the map between your lot and your neighbor's lot is an interpretation of the deed description, not a field-verified boundary. Using a parcel map to place a fence or decide on a construction setback is not reliable and can lead to encroachment disputes.
That said, assessor maps are a good free starting point for understanding your property's general shape and dimensions before engaging a surveyor.
Recorded Plat Maps at the Parish Courthouse
If your property is in a recorded subdivision, the original subdivision plat is on file at the parish courthouse in the conveyance records. The plat shows every lot in the subdivision with dimensions, lot numbers, street names, and the location of any monuments set at the time of platting. A plat is a more authoritative document than a parcel map and is the basis for the legal description in your deed.
You can request a copy of the plat from the parish clerk of court's office. In many parishes, plats are available online through the clerk's digital records system. Once you have the plat, you can see the stated dimensions of your lot, which lots are adjacent, and where the subdivision boundaries fall relative to surrounding streets and tracts.
A plat gives you the intended layout at the time the subdivision was created. What was on the ground may have shifted over decades due to construction, fence installation, and legal disputes between adjacent owners. The plat remains the record, but a surveyor's field work determines what the corners look like today.
Louisiana Atlas GIS Viewer
The Louisiana Spatial Reference Center at LSU maintains a free public GIS viewer at gis.atlas.lsu.edu. This tool aggregates spatial data from across Louisiana state agencies and provides aerial imagery, topographic layers, and parcel boundary data on a single map interface. It is one of the most complete free property research tools available in Louisiana.
The GIS viewer is useful for understanding the context around a property: nearby waterways, flood zone boundaries, adjacent land uses, and terrain. Like all GIS-based parcel tools, it provides spatial approximations based on existing records, not field-verified boundaries. It is a research starting point, not a substitute for a professional survey.
Reviewing Old Arpent Descriptions in Historic Deeds
For properties in river parishes and old settlement areas, understanding the historic land measurements in your deed is often the key to understanding your boundaries. The French long-lot system, still visible in the narrow strips of property running back from the Mississippi River and other waterways in St. Charles, St. James, Assumption, and Iberville parishes, was laid out in arpents. One arpent equals roughly 192 feet.
If your deed description refers to “4 arpents front by 40 arpents depth,” it means a lot approximately 768 feet wide and 7,680 feet deep. These dimensions were set during the colonial period and may or may not align perfectly with modern survey data. A licensed PLS researching one of these descriptions will check the original colonial survey records, compare against adjacent deeds, and reconcile any gaps or overlaps before setting physical corners.
Hiring a Licensed PLS for a Legally Binding Result
Every method above, deed review, assessor maps, recorded plats, GIS viewers, provides context and approximation. None of them produces a legally binding determination of your property lines. Only a survey completed and signed by a Louisiana LAPELS-licensed Professional Land Surveyor establishes the legal boundary in a form that can be recorded, relied upon in court, accepted by title companies, and used to resolve disputes.
A licensed PLS will research your deed and adjacent deeds, locate any existing monuments from prior surveys, take field measurements using GPS or total station equipment, and reconcile what they find on the ground with what the legal description says. They set physical corner markers, typically iron pipes or concrete monuments, and produce a signed and sealed plat you can record at the parish courthouse.
That plat is your legal record of the boundary. If a neighbor later disputes the line, the recorded survey is your evidence.
Find a Licensed Surveyor in Louisiana
Ready to get a definitive answer on your property lines? Our Louisiana surveyor directory lists licensed professionals by parish, sourced from LAPELS records. Search by parish to find a qualified PLS in your area.