You will can make a basement, for expansive things, or second floor with windows for shoting enemy.
For switching floors can by in bottom right a button for switching.
You will can make more floors, but you must research floors.
We do not need another suggestion thread for z-levels / multi-floored buildings as it has been suggested to death. And all for a suggestion that isn't going to happen. Please use the search function in future to check for existing suggestion threads before making a new one.
Thread locked.