Cadastral Survey and As-Built Plan by Drone

Precision topographic surveying is at the heart of many land and planning processes: land subdivision, as-built plans after construction, easement establishment, building permit applications. Photogrammetric drone surveying complements the land surveyor's work by producing an exhaustive terrain survey in a fraction of the time of a traditional total station survey, with an incomparable richness of data.

When is a drone survey appropriate?

Land subdivision and boundary marking

Before a sale or subdivision of a property, the owner must have a land measurement document prepared by a chartered surveyor. The drone survey provides the complete topography of the parcel — contour lines, visible boundaries, existing structures — which forms the basis for the surveyor's area calculations and boundary marker positioning.

As-built plans

An as-built plan is the document that certifies the conformity of completed works with the building permit drawings. It is mandatory for public buildings and required by certain private project owners. The drone produces an accurate survey of the entire parcel — buildings, roadways, visible networks, landscaping — in a single flight session.

Land studies and property diagnoses

Before acquiring land for a construction or development project, the topographic survey assesses project feasibility: slopes, buildable areas, positioning relative to boundary setbacks and easements. The drone produces this survey quickly, with complete parcel coverage even on rough or wooded terrain.

Municipal assets and GIS

For local authorities wishing to update their geographic information system (GIS), the drone produces up-to-date orthophotos and large-scale digital terrain models, usable in GIS software (QGIS, ArcGIS) for municipal asset management and urban planning.

Accuracy and deliverables

Photogrammetric drone topographic surveys produce georeferenced data in the French legal projection systems (RGF93, Lambert 93) with the following accuracy levels:

• Orthophoto: 3 to 5 cm/pixel resolution depending on flight altitude
• DTM: altimetric accuracy of ±5 to 10 cm with control points
• Contour lines: 20 to 50 cm equidistance depending on required precision

These deliverables are compatible with CAD and GIS software used by chartered surveyors, engineering consultancies and local authority technical departments.

What we deliver

• Georeferenced orthophoto (GeoTIFF) in Lambert 93
• 3D point cloud (LAS) with ground/vegetation/building classification
• Digital terrain model (raster GeoTIFF)
• Topographic plan (DXF/DWG) with contour lines, buildings and visible networks
• Accuracy report with control point description and deviation statistics

Complementarity with chartered surveyors

Drone surveys do not replace the chartered surveyor for regulatory acts (boundary marking, DMPC). They complement their work by providing an exhaustive topographic base that reduces total station survey time and enriches the file documentation. Many surveying firms now integrate drones into their workflows for large parcels or complex terrain.

Our field approach

We use the DJI Matrice 4TD for precision topographic surveys, with RTK GPS ground control points to guarantee geodetic data quality. Missions are planned in agreement with chartered surveyors or project owners so that deliverables integrate directly into their workflows.