@ciane : Again: thank you!!!!
Atm I have the master bedroom and the nursery on my second floor and the rest of the bedrooms on the third floor and wanted the family to sleep on one floor, because sometimes I can´t see that some of them is awake already and has already done something stupid. :D
When I play with my main family and some of the adult children come as visitors around and stay for a bit, there are always some Sims who like to flirt with siblings, fathers-in-law, daughters/sons.....
So I´d like to let them sleep on one floor.
But I already know what to to with the extra room downstairs. There will be a big library with some desks.
The house has nearly the right size, perhaps it must be getting a bit bigger for all the Sims.
Thank you for your effort!!!!!