"I could find no record of the original defenses, but they were likely broken when the Dragon-Blooded raided the manse.  As for their recent additions, I could not say.  Essence locks are fairly typical.  I doubt they have the resources to use First Age artifacts, though some recent ones may have been added.  At worst, there may be a First Circle demon or two bound to guard the manse, but they are simple enough to deal with."