Fabian,
Thanks for the compliment. No I did not model the project in Sketchup, I merely converted it to KMZ from Sketchup. I model my designs in Cadsoft Envisioneer for 2 reasons: 1. Envisioneer is parametric allowing much quicker develpment of complicated models, because each line drawin (i.e. walls) are actually 3d assemblies. Or each element inserted can be put in as a block. So it's like using sketchup, but for actual building purposes it's quicker if you need complex detail.
2. Envisioneer lets me move more quickly to blueprints than I can in Sketchup. However if I need to have a 3-D view that is dimensioned I will import my model to Sketchup, dimension it and export the view back to Envisioneer for inclusion with the rest of the drawing. I hope this helps!
Keep up the excellent work!