Within MicroStation v8i (SELECTSeries 3) (version 08.11.09.397), where are the area unit defined? The linear units are defined in the unit.def file, but this file does not include area units.
AreaAnnotator is freeware for MicroStation.
AreaAnnotator works with MicroStation tags to measure objects automatically. One of the ways you can configure it is to apply a scale factor to measurements to calculate values in units other than MicroStation master/sub units.
So, if your DGN units are metres and you want areas shown in hectares, or if your master units are feet and you want areas shown in acres, then it's straightforward.
Regards, Jon Summers LA Solutions