I generally don't have any problems inserting a DGW at origin on a worksheet.
If you get any problems you could keep the original working unit (most likely meters instead of mm), this scales the problem down by a factor 1000.
That said, the model is always on the origin to avoid the problems Scott refers to.
The location you set at Project Location (CTRL + W) is the real world location of your project origin. You might need to convert cartesian to GPS, depending on your local standards, to get an accurate lattitude/longtitude.
Erwin Edel, Project Lead, Leloup Architecten
www.leloup.nlArchiCAD 9-26NED FULL
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