I have been duly reprimanded by my ex-fellow student and architectural adventurer, Bobby H, for the above comment about Sketchup and orthographic drawings.
It is with great regret that I have to inform you that you have given incorrect information to readers of your blog regarding the export options of sketchup. I have been using this programme for some time and must report that you can indeed export orthographic projections directly into autocad at the correct scale. Indeed, so accurate are these exports that a recent PFI bid I was involved in was drawn almost entirely on sketchup, including plans, sections and elevations.