Lower/Raise

[Jorge Araya]

The edit area command seems to do it, it takes a bit of research to make it work but, I am testing it with somewhat undesirable results.

Select Edit>Edit Area>Edit Area All Floors>draw marquee>transform replicate>absolute location>Z Delta>enter the desired floor level.

Your building should move in its entirety in the up or down axis...

Unfortunately only the roof planes were dropped, the building is still at its original position.