My girlfriend is an architect student and she wants me to render her design to look realistic. She has modelled it (rather, she will model it) in sketchup. I was wondering if anyone knew what the best way to model it would be. I have had some sketchup models before and they have always been one piece of geo triangulated. This makes it very complicated when UVing and applying shaders... I basically can't be bothered separating the model

Is modelling on layers the best thing to do, or is there an export option i don't know about?
thanks.