Otherwise he wanders around mysteriously.

Surely it would be just as confusing if he's building the basement later. Perhaps instead I could get him to say, Hey blah, as you can see i'm busy building x, currently working on building the basement. At least then you at least know what's going on.

Added chat for the carpenter that informs the player what building he is currently building in b608785. Should hopefully makes it less confusing when he is wandering around in the same area :)