Base quantities that are common to the definition of all occurrences of stair flights.
The length of the object.
Measured along the walking line.
Total gross volume of the object. Openings, recesses, enclosed objects and projections are not taken into account.
Total net volume of the object, taking into account possible processing features (cut-out's, etc.) or openings and recesses.
Total net volume of the stair flight. Openings and recesses are taken into account by subtraction, projections by addition.