That's the locked mansion. The grandma is outside with another lady, and she has the key. The mansion itself is deserted and dilapidated, its only purpose really is for you to search through it for quest items. Keep in mind this part occurs fairly late in the Kiel Hyre quest.
I really enjoyed that quest, it was one of the most fun quests out of all of episode 10 for me. I remember how I would always tank the Kiehl miniboss at the end with mental strength. xD Good times~
EDIT: Now, there's another building in Juno, where a lady will kick you out after you walk past a certain point. That's not the grandma building, to be double sure, is it?
That's for a different quest altogether. I think she's a doctor for some quest that originates in Gonryun/Kunlun. The Broken Sword Quest, I think?
Edited by Zeniachan, 26 June 2012 - 08:14 PM.