5 Common Mistakes When Working with Dutch Cadastral Data

Learning from Others' Mistakes

Dutch cadastral data from the Kadaster is some of the highest quality property data in the world. Yet even experienced GIS professionals sometimes stumble when working with it. Here are five common mistakes and how to avoid them.

Mistake #1: Ignoring Coordinate System Differences

The most frequent error is mixing up coordinate systems. Kadaster data is typically provided in RD (EPSG:28992), but many web applications expect WGS84 (EPSG:4326).

The Fix

Always check the CRS metadata before importing data. When transforming between systems, use proper transformation grids (RDNAPTRANS) rather than simple mathematical conversions. TopoLab's API handles this automatically when you specify your preferred output CRS.

Mistake #2: Treating Boundaries as Absolute

Cadastral boundaries represent legal ownership, not necessarily physical features on the ground. A parcel boundary might run through the middle of a house, fence, or driveway.

The Fix

Understand what cadastral data represents. If you need physical boundaries, consider combining cadastral data with topographic or aerial imagery. Don't make physical assumptions based purely on legal boundaries.

Mistake #3: Missing Temporal Aspects

Parcels are created, split, merged, and retired over time. Using a snapshot without understanding its temporal context can lead to incorrect conclusions.

The Fix

Pay attention to date fields. For historical analysis, use time-series datasets that track changes. When matching parcels across systems, use persistent identifiers rather than relying on geometry matching.

Mistake #4: Misinterpreting Attribute Values

Attribute fields like 'oppervlakte' (area) or 'bestemming' (designation) have specific meanings in Dutch land law that may not align with common assumptions.

The Fix

Read the data documentation. The Kadaster provides detailed attribute definitions. When in doubt, consult official resources or domain experts. Don't guess at meaning based on field names alone.

Mistake #5: Overlooking Data Currency

The Dutch cadastre is updated continuously, but data you downloaded last month may not reflect recent transactions or boundary adjustments.

The Fix

Check the extraction date of your data. For applications requiring current information, use live API access rather than static downloads. Implement data refresh procedures appropriate to your use case.

Conclusion

Dutch cadastral data is a powerful resource, but like any specialized dataset, it rewards those who understand its nuances. Take time to learn the data model, read the documentation, and test your assumptions before building production systems.