Imported Dwgs not placed at datum level

I import a Dwg drawing into SU, and then start tracing-off the drawing to create the 3D model. However, when I switch on Shadows I find that the Dwg and the model that sit on it are located about 230mm above the shadow plane. This means that there is a gap and the shadows are offset and disconnected from the model. See attached image.

Your profile says you are using SketchUp 2015 Free (Web) which is impossible. What version are you really using? Please correct your profile.

Is this a .dwg file you are referring to? It would be easier to help you if you share the file as well as the .skp file so we can see what you are working with. Your screen shot doesn’t provide enough information to identify where the problem is.

I use the free version at home and the full version at work.

You still haven’t answer my other questions or share anything that would help us help you.

I only see two possibilities: Either the items in the DWG are located above the red-green (xy) plane, or you have inadvertently moved it up. Post the DWG and your model.