Description du projet

Why is there no floor on two rooms? I tried many different things but nothing worked so far, there are always some rooms without a floor. HELP would be highly appreciated. I am very frustrated with the program so far. The only reason why I switched from Sweet Home 3D was the option to include a second floor but exactly that isn't really working. Also, when building on a floor plan, there is no semitranslucency to see where the windows where placed etc..