Context: The protagonist is searching for a girl in his house, and since his house is really big he has yet to find her.
I don't understand this sentence.
捜していない=Not looking for; Not searching
となると=If it's the case; If it comes to that
後は道場か土蔵ぐらいなものだろう。=After that, the dojo or the storehouse.
I don't understand why it's 捜していない.
If I do not look until here, After that, the dojo or the storehouse.
But it does not make sense, does it?