having a Wall with two additional walls for outer layer, both having offset set as a formula of middle wall.Width by half, gives a nice Multilayer-wall.
Adjusting middle wall.width let outer layers keep sticking on its sides.
Problem occurs when a window is added to such a middle wall: The new generated parent middle wall gets the default width and the outer layer walls don't stick any longer nice to their middle Wall.
Is that a bug?
Strange thing by the way: all parent walls get default width but are displayed with child width...