If you have created a number of spaces in your drawing with an area calculation standard, and then change the area calculation standard for the drawing, the spaces get recalculated according to the rules of the new standard. The classification definition for the new area calculation standard is inserted in the drawing, but the space might need to get re-classified according to the new standard. For example, if you calculate your spaces according to the SIS standard, and classify a space as “Shaft”, and then re-calculate the spaces according to the BOMA standard, then the initial BOMA classification is set to “Unspecified.” You need to select a corresponding BOMA classification, like for example “Major Vertical Penetration.”
When a new area calculation standard is selected for the drawing, the classification definition for the previously used standard is not removed, but remains in the drawing. This can be helpful if you need to switch back and forth between different standards, and do not want to lose the classifications of the currently not active standard every time you switch.
If you know that you will not be using a certain standard anymore, you can delete its classification definition from Style Manager. To delete a classification definition, it must not be referenced by any objects. To remove the references to the classification standard, change all spaces that use a classification from this definition to *Unspecified*.