Plot Boundaries from a Registry Coordinate List: Building the Outline and Seeing It on a Map

A common situation: you have a land registry extract with a table of boundary point coordinates, and two questions follow — how to build the plot outline from those coordinates, and how to convert them into a GPS-friendly form so the plot can be seen on an ordinary map. Below is a walk through both: first the outline in CAD, then the conversion into latitude and longitude, then a base map underneath.

If you have a cadastral number but no extract, that is a different scenario, covered in How to open a land plot boundary in AutoCAD by cadastral number. Here we assume the coordinate list is already in your hands.

What the extract actually contains

The boundary point coordinates sit in the section describing the location of the plot's boundaries. The table lists a point number, X, Y and the mean square error. Next to it the coordinate system is always stated — usually a local metric grid for the region.

Three things are worth writing down separately, before any drawing starts:

• The coordinate system and its zone: without it the numbers mean nothing.
• The traverse order of the points — normally clockwise, closing back on the first point.
• The plot area from the extract: you will need it as a check.

The main trap: X means north

In surveying the X axis points north and Y points east. In AutoCAD it is the other way round: X runs right (east) and Y runs up (north). So a pair from the extract goes into CAD in reverse order: whatever the table calls Y is entered first.

The symptom of getting it wrong is an outline that looks mirrored or rotated by 90 degrees, while the area may still match. Orientation relative to roads and neighbouring plots is the most reliable check.

Step 1. Build the outline

The most direct way, with no plugins:

1. Command PLINE (polyline).
2. Enter points as comma-separated coordinates, remembering the swap: for a row reading X=6234567.89 Y=2234567.12 you type 2234567.12,6234567.89.
3. At the last point close the outline with the C (Close) option — do not draw the closing segment by hand, or a micro-gap remains.
4. Drawing units are metres, scale 1:1.

With many points it is easier to collect them into a CSV and feed them through a script or a point import — the principle is the same, only the column order matters.

The check. Running AREA on the finished polyline should reproduce the area stated in the extract to within a tenth. If it does not, you have almost certainly missed a point, swapped the columns, or left the outline open.

Step 2. Convert into latitude and longitude

To see the plot on an ordinary map or push it into a handheld receiver, the coordinates have to move from the local grid into WGS-84 (EPSG:4326).

1. Save the points into a CSV: id,x,y, with the values exactly as printed in the extract.
2. In QGIS: Layer → Add Layer → Add Delimited Text Layer. In the X field and Y field boxes map the columns correctly: X field is the easting, which the extract calls Y.
3. Set the layer's coordinate system to your local zone.
4. Right-click the layer → Export → Save Features As, format GeoJSON or KML, CRS EPSG:4326.

The resulting file opens in any mapping application, and the plot appears where it belongs. One catch: not every local zone exists in the standard EPSG database, so occasionally it has to be described as a custom CRS with explicit projection parameters. The mechanics, the parameters and the usual mistakes are covered in Converting cadastral coordinates between local grids and WGS-84, and the design of the local systems themselves in Local coordinate systems.

If after the conversion the plot has moved hundreds of metres or kilometres, the culprit is usually the wrong zone rather than the maths.

Step 3. Put a base map underneath

An outline on its own is a polygon in a void. To make it readable — where the road runs, where the neighbours are, where the river is — you lay a cartographic base under it: select the territory and download it as DWG or DXF, choosing the same coordinate system you used for the outline. The same caveat as in step 2 applies here: local systems appear in the list as Gauss-Krüger zones marked "~MSK-NN" — an approximation, not the region's official local grid. If the outline was built in the real local system, enter it as your own proj4 or WKT in the custom CRS field. And in either case check the fit against a known point — a building corner, a junction, the corner of a neighbour's fence: the base must land on the outline with no shift. For maps and the web, GeoJSON is handier.

In AutoCAD it is cleaner to attach the base as an external reference: command XREF, insertion point 0,0, scale 1, no rotation. Then send it back with DRAWORDER → Back and keep the plot outline on its own named layer.

One point deserves saying plainly: an OpenStreetMap base shows the surroundings but is not a legal document. The authoritative source of the boundaries is the registry extract itself, and work on the ground is done by a licensed surveyor.

In short

• In the extract, find the boundary point table and, crucially, the coordinate system.
• Surveying X is north, Y is east; in CAD the pair is entered in reverse order.
• Draw the outline as a polyline and close it with the Close option; units in metres.
• Check yourself with the area: AREA must match the figure in the extract.
• For maps and GPS, convert the points from the local grid into EPSG:4326 via QGIS.
• Take the base map in DWG in the same CRS, attach it with XREF sent to the back, and check the fit against a known point.