An OLD GUY speaks:
Depending on the accuracy of your drawing and output, you CAN scan the image, place it as a figure in ArchiCAD and then trace over it. Assuming its a construction document with dimensions listed, that is great, or....
Big deal. This is an immense waste of time, especially for a rectilinear building and impossible if it is not.
Assuming tha you want to recreate a floor plan, say, here's what you do:
Whether or not you place an image UNDER your ArchiCAD layout for guidance:
Develop a dialog protocol for use with an assistant:
1: to analyse repeating building components and exploit them by mirroring, copying and dragging segments appropriately.
2: to proceed to draft walls using strict discipline having the assistant call out the coordinates as you work your way clockwise around the building. It is faster than you think if you use the continuous wall tool and simply have them shout the x and y for each new point.
3: Then you go back and place the windows.
4: then you copy and flip the repeating bits around...
This is faster than trying to read through the layout to the underlying scan.... because it takes too long to locate dimension data - especially on older, hand lettered drawings AND it is impossible to make a scan of an architectural plan resolved enough to get the pixels small emough to scale from....
Dwight Atkinson