I've been working for a couple years with FP10 and FP11 and have several projects still in that mode.
I'm doing some things now in TFP12.
I can do terrains pretty good but wanted to duplicate what I had in FP...and the tools are different and hard to re-produce FP11 in TFP12.
So the answer was to export the FP11 terrain (turn everything off from view except the terrain, then export) as .dxf and import that file into TFP12...scale worked too.
See attached image as an example...and the terrain also was "cut out" around the house....so I can position it and no intrusion in the TFP house.
Hmmmm....Now....from other topic in this forum on exporting .3ds.....maybe the trick will be to "turn off" visibility of TFP12 terrain to export an object without the terrain attached.
http://forum.turbofloorplan.com/index.php/topic,243.msg1043.html#new replies #2 and #3