there are a lot of similar requests, which I believe would be solved with this. https://sourceforge.net/p/sweethome3d/feature-requests/765/ https://sourceforge.net/p/sweethome3d/feature-requests/1129/ https://sourceforge.net/p/sweethome3d/feature-requests/71/ https://sourceforge.net/p/sweethome3d/feature-requests/1052/ https://sourceforge.net/p/sweethome3d/feature-requests/1059/ https://sourceforge.net/p/sweethome3d/feature-requests/919/ https://sourceforge.net/p/sweethome3d/feature-requests/750...
see https://sourceforge.net/p/sweethome3d/feature-requests/1130/ for a possible solution
see https://sourceforge.net/p/sweethome3d/feature-requests/1130/ for a solution
I created a draft version already five years ago, but missed to publish this. Updated the code for current svn. Alignment of the wall can be changed between left, middle (default), right. When changed to middle, files stay compatible with unpatched version. Please give this patch a try.