May 30, 2017, 05:11:55 pm
Thanks for uploading the model, Jan.
1) It does not look like a model that was made in SketchUp. Do you know which 3D application it's from?
2) The reason some faces aren't visible in Lumion is that the Default material in SketchUp is invisible in Lumion. This is by design. To get the whole model to be visible in Lumion, please assign proper materials to the various components (doors, windows, floors, walls etc).