LOL, his room/area is in one of the towers... probably the one with the hole in the roof. Mike Laidlaw's Inquisitor likes to take a shortcut to his door by jumping from the battlements rather than taking the stairs. 
Looking at the size of Skyhold, my quizzy will want to make a Quick Travel point to Cullens door, sod the freakin stairs >.>
Cass - We have one more Quick travel icon to use Quizzy, I think we should place it at the camp in the far end of the marshes..
Quizzy - *thinks*
Cass - It makes sense from a logistical stand point......
Quizzy - "hmmmm"
Cass - You don't seem convinced quizzy, any better ideas where to place our very last travel point?
Quizzy - *nods & runs upstairs to Cullens door*
Cass - *head-desk*