I'm an architect, trying to bring a number of data sets together for use in a CAD package (AutoCAD). I have some georeferenced images (.jpg">
QGIS supports DXF through OGR. It's a bit of a minefield, though, as the format isn't clearly defined.
Can you export your model in any other format than SketchUp SKP? QGIS is a traditional “2½D” GIS system, so 3D models would be represented as 2D with elevation as an attribute at each node.