The portion of wall they completed ran from the corner
(Nehemiah 3:31) to the Sheep Gate.
This section of wall was directly to the north of the temple complex. It is likely that goldsmiths and merchants did business with temple devotees in this space just outside the temple. So their repairing this section of the wall would be akin to so many others rebuilding outside their own homes.
32 And between the upper chamber of the corner and the Sheep Gate the goldsmiths and the merchants repaired.