A benchmark is a stable survey point that serves as the starting point for measuring elevation. Benchmarks must be particularly stable, as the required accuracy is one millimeter or less.

The building authority maintains a flawless, homogeneous network of elevation benchmarks (4th order levelling network) for the urban area, from which you can request extracts for a fee.

The costs are calculated on the basis of the statutes governing the collection of fees and expenses by the building authority of the state capital of Mainz.