This is a very old forum.. however if anyone is still interested in SketchUp and BIM, here is a solution: http://forums.sketchucation.com/viewtopic.php?f=323&t=41840
The plugin provides an easy way to create parametric primitives like walls, beams, columns etc inside SketckUp. It follows a standard process-flow similar to popular BIM software like Revit.
best!
Dex