You could add a new wall to fill in the gap, but you may have issues getting it to trim properly.
Or it may work just fine.
If not then mark that wall as 'to be demolished' and and then add a new wall.
If that is one tall wall at the end, you may want to split it half way up so you only demolish and replace the top part.
One of the forum moderators.
Versions 6.5 to 25
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