Hi Thorvald,
it's a great difference if you have the HRB-Editor (this is the German name) or if you have not. Every wall keeps the settings, with which it was created. If you want to change a wall, it is not enough to change the wall type. Better is, you create a new one and then give the new properties to the wall (using 3-01). The new type may have a different number of slices, and/or different thickness of slices. You decide, which part of the wall shall keep it's place: front, backside or reference axis. All changes are visible immediately in the ground walls.
So when you have no HRB-Editor, all beams will stay at the same place where you put them before. All new beams are relative to the new slices.
But if you have the HRB-Editor (it's a really mighty tool), you can recalculate single or various groups of walls. In this editor you can set hundreds of switches, they can recalculate the whole building in a very short time by using new definitions.
My English is not good enough to explain it more detailed, but be sure, the program is very helpful especially if you change settings and wall properties!