It says Dormitory when you pick up the map, as in "You've picked up the Dormitory map". I'd take a screenshot but I don't have a save nearby with the map not picked up.
In the Japanese version it's "yorishusha" or "yorishoshusha" but I have no idea what that means.
And then remake calls it Residence, and it's the only name that has changed. Between that and the other data I've already mentionned (the in game files having the Guards in the main mansion, which makes sense since it's the front, and scientists in the Dormitory where they have lab stuff), it's easy to see Guardhouse is wrong