Building walls

[mihai.s]

You could select that group, copy and paste in place, then assign to another layer. After that, you just edit the new group as you wish.

Avoiding the merging of lines of different parts

Layers are only for visibility. Draw raw geometry on Layer 0, then create Groups (walls, floors…) and assign to layers. When you want to print only the walls, turn off the other layers. [ba-02]