I sended you the file's.

thanks for helping

I try but still the same problem.
In 2d i see level by level but in 3d the problem keeps, I gave the floor a structuur but it din't help :(

BTW i make a mistake :)
i sayed floor, but mean room (levels)
i have 3 rooms (3 tabs) (3 levels)
first room = basement = first level
second room = first room ...

I have a little problem.

In 3D view in options, i can choose to show all levels of my house = no problem [:)]

But when i select show only selected floor then the 3D show me the selected AND the underlying floors also [:((]

i mean when i selected the basement:
i see only the base in 3D.

When i ...