Planning glossary
Datum
A fixed reference point, line, or elevation from which other measurements are located.
Example
All floor elevations can reference a project datum of 0 mm even when real-world survey elevation is not yet known.
Related concepts
Elevation
Either a height relative to a datum or an orthographic view of a building face; context should make the meaning explicit.
Read definitionCanonical unit
The single internal measurement unit used as the source of truth while the interface displays other units.
Read definitionTolerance
The permitted or expected variation from a nominal measurement, distinct from display rounding.
Read definitionUse the term in context
Definition boundaryThis planning definition is not a substitute for the definition in an adopted code, standard, contract, manufacturer instruction, or professional document. Confirm the controlling meaning for the project.