I am writing to inform you that I wish to move into a new room next semester. I would like to have a single room, because I find the present sharing arrangement inconvenient.
I am dissatisfied with my present roommate because of his inconsiderate behavior. For one thing, his friends are constantly visiting him; for another, he regularly makes calls at night. In addition, he often uses my things without asking for my permission. Under such circumstances, I find it difficult to concentrate on my studies, and I am falling behind in my assignments.
I believe you will agree that the only solution is for me to move into a room of my own, where I will be free from these kinds of distractions. I would be very grateful if you could arrange a single room for me, preferably not in the same building.