Parallel defensive walls with base..?

[Wacky2Backy]

I have a big building and I want to set up a defensive wall perimeter, but I can not make it parallel/square with my base. It bothers the crap out of me if its slightly uneven. It's easy to make it look parallel on a small base, but my base is 9x6. There needs to be a way to snap wall to be square with base. Does anybody have any ideas on making the wall perfectly parallel with base?

[BladeofSharpness]

I guess it's not possible to attach a defensive wall to anything but a defensive wall?
You can anyway always place a DW the closest possible to a strut, do the same for the nearby strut, then remove the 2 struts and try to place more DW in between the 2 initial 2 DW? Rinse and repeat for each strut (which are neatly placed).

[threethreethree]

^ Yes. Always lots of creative options using what's at hand. In first game, i'd use the ghosts of other things and their right angle snapping and other features of them to survey, measure, etc, then delete those ghosts after beginning what i really want to build. In this game, connecting things temporarily to get that snapping then removing those elements sounds like a great idea.