The portal compares the buildings visible in the airborne LiDAR point cloud with the buildings in the Polish land and building register (EGiB). The result is a map of differences and a list of places to check before field work for a design base map, an EGiB update or a register modernisation. All data come from the free resources of GUGiK (the Polish Head Office of Geodesy and Cartography); the portal does not send anything to external AI tools.

The result is a hint, not a survey. A LiDAR outline is the roof with its eaves, not the ground-floor footprint, and EGiB from the public service may be incomplete. Every change must be confirmed by a survey that meets the technical standard (0,10 m relative to the control network for buildings).

1. On the Map and analyses page, search for a parcel (identifier 280501_1.0002.1309/5 or precinct and number: Ełk 2 1309/5) or an address (Ełk, Mickiewicza 4). You can also click the map in the middle of the area.
2. Choose how to mark the area: a square around a point (side 150-750 m) or a rectangle drawn with the mouse. The limit is 0,60 km².
3. Name the analysis and click Run analysis. The portal looks for the most recent LiDAR point cloud in the GUGiK index, downloads the LAZ sheet, builds building outlines from class 6 points, downloads EGiB buildings from the national WFS service and compares the two sets. The comparison covers only the part of the area where GUGiK provides a point cloud; the analysis page shows this coverage. If the cloud has no building-class points or EGiB returns no buildings, the analysis page shows a warning about the limited reliability of the result; when a GUGiK service fails or returns incomplete data, the analysis ends with an error instead of an apparently complete result.
4. On the analysis page, review the items on the orthophoto, set the status (to check, confirmed, rejected) and add notes. Changes are saved immediately and recorded in the change history (who, what and when). If the same item was changed in another window in the meantime, the portal reports a conflict and loads the current state instead of overwriting it.
5. Download the results: a PDF report with your firm card in the header, CSV for Excel (PL-2000 and PL-1992 coordinates), DXF for CAD (one layer per category, item number next to the object, firm title block) or GeoJSON for QGIS (PL-1992) and GeoJSON WGS84 compliant with RFC 7946 for web applications, or GeoPackage for QGIS in PL-2000 with five layers (changes, objects on the boundary, LiDAR outlines, EGiB buildings, comparison extent). Each result stores the parameters, the portal version, the EGiB download time and SHA-256 hashes of the input data (each LAZ file and the content of the EGiB data).

• The orthophoto, the digital terrain model and the geometry of parcels and buildings are provided free of charge (Art. 40a(2)(1) of the Geodetic and Cartographic Law, PGiK); the source must be stated in the work (Art. 40c(3)).
• The national EGiB WFS service returns the building geometry, identifier and type, without personal data. The portal does not accept files from the county records office: materials released for a registered job may be used only for that job (Art. 12(8) PGiK).
• The choice of method and the responsibility for accuracy rest with the surveyor in charge (§ 3 of the technical standards). The list from the portal helps plan the survey; it does not replace it.
• Each account sees only its own analyses; the administrator sees all of them.

The same chain can be run in QGIS 3.44 LTR with the scripts described in the manual (tested on the Ełk sheet N-34-81-D-a-2-2-2-1). Download the PDF manual.