Cadastre

Preparing KML for cadastre: showing a parcel correctly in Google Earth

10 min read June 10, 2026

KML is a practical way to show a parcel to a client or field team. But it is a visual exchange format; without correct transformation the parcel can shift and be misread.

Field takeaways

KML uses WGS84 geographic coordinates, not projected metre coordinates.
Coordinate order is longitude, latitude, altitude.
A polygon ring must be closed: first and last coordinates match.
Google Earth imagery is visual context, not a legal cadastral base.
Official work follows authorised data and required institutional formats.

What KML is good for

KML is excellent for visual communication. A client or field team can see the parcel in Google Earth. It is not, by itself, an official cadastral deliverable.

The coordinate-order trap

KML writes coordinates as longitude, latitude, altitude in WGS84 geographic coordinates. Projected metre coordinates such as TUREF/TM must be transformed first.

If the source data is ED50, solve the ED50 to TUREF/WGS84 transformation first, then write WGS84 geographic coordinates for KML.

Polygon closure and visual checks

Close the polygon ring, avoid crossed vertices and reopen the export before sending. Satellite imagery may have offset, so do not treat it as legal boundary evidence.

In the field · MapLab Survey

Measure, check and deliver in the right format.

MapLab Survey is a mobile field app for RTK/GNSS points, drawings, area/volume calculations, coordinate conversion and export to DXF, KML/KMZ, GeoJSON and CSV. Capture, calculation and export can work offline; live NTRIP corrections and online basemaps need connectivity.

Get MapLab Survey

Frequently asked questions

What is KML coordinate order?

Longitude, latitude, altitude.

Can TUREF coordinates be written directly to KML?

No. They must be transformed to WGS84 geographic coordinates first.

Is Google Earth a legal boundary base?

No. It is visual context.

KML or KMZ?

KMZ is a compressed package that can include KML and related assets.

Technical references

The field guidance in this article is aligned with the technical and official references below.