In construction, a datum point is a known point of reference on the basis of which further measurements or analysis can be made. The point can be based on the finished floor level, an existing building or a benchmark.
When based on a benchmark, a datum point refers to a position above sea level. Benchmarks form a network of reference points from which a datum can be adopted. These are utilized in the construction of new houses, roads or stone pillars. A datum point can also be used in modeling geometry, where it’s possible to add several points on a model.