[QUESTION] Floor bug

Problem: Literally it is impossible to create a second floor unless you are done with everything in the first floor.
Q1: Is there any way to define upperfloor once the first floor changes?

Let me explain:

For example, I would like to create second floor but there are still lots of things to do in the first level as can be seen in this picture ( https://i.servimg.com/u/f52/19/99/19/34/screen12.png )

In this case if I want to create second floor this is how it looks like, which is very normal "I suppose" because there are no walls downthere.
( https://i.servimg.com/u/f52/19/99/19/34/screen11.png )

The problem starts after this point.

Even if you finish your walls and want to see the same level in the second floor seems not be working as can be seen here

picture with walls ( https://i.servimg.com/u/f52/19/99/19/34/screen10.png )

after the walls, the second floor looks still same as it's also showed previously ( https://i.servimg.com/u/f52/19/99/19/34/screen11.png ) this second level literally has been blocked for any furter extensions.

Hello.
If you add new floor, you can edit foundations however you want, even for the areas, that has no foundations below (respecting isometrics). Every floor could be modified apart from other floors. Only one thing that is necessary to be placed in the same place on every floor are the elevators.

But if you have already two floors and on the first one you add some room with new foundations - on the second floor you have to make the same foundation area. If you will not do this you may experiences something that may be visible as bug - you will see through the floor.