@tt_su said:
In SketchUp everything is built around Z being up. You will probably find it easier to convert imported geometry to match this and have the exporter adjust the axis again later for the target application.
Thank you for this info. After a Google search I started to assume that this would be the case, but you have confirmed it. Being a beginner in SU I didn't want to start coding and hacking a 'square peg into a round hole'. I will code a function to transform the geometry between the two programs so that the data will react to each of the programs assumptions.