I already tried ~3 different models, all with the same problem. Maybe I'll try some more before I start mucking around with it.

I don't really need the inside, it's just for a home visualisation. Maybe it would be enough if I just clear the inside textures. As I never worked with Sketchup before I'd need to try out stuff. But it doesn't really slow down SH3D. I now have the full house with various furnitures, some environment and cars. Except for occasional freezes I can work fine. And the freezes I already had from the beginning with a very simple house and just a few walls, especially when changing views or making photos.

I'll report if I find a solution for the model.

Thanks