Sims refuse to do University homework in their own room!

Two more ideas that are simpler than removing doors.
1. Lock the doors. You can either lock your Sim into the room you want or lock your Sim out of the room you don't want.
2. Change the bed assignments. Assign your Sim to the "homework bed".

Since University I've noticed that no one wants to do homework alone. I have a save with 5 teenagers. Each has their own room and their own desk (okay, the twins share, but they still have two desks). They will all troop down to the dining room table to do homework together, rather than do it on their desk.

In another save I'd have a kid playing with the dollhouse in his room. I'd put the homework on his desk, tell him to do it, and he'd go down to sit with his sister who was painting instead.

Edit from last night's play session - Next generation. Dad is in Uni. Kid is a toddler. Mom is in the culinary career, so at work. Dad goes in to sit on the kid's bed while the toddler is asleep to do his homework.

Later, Kid is a child. Kid was given homework in his room. He goes down to homework by his grandpa (NPC) who is visiting and using the yoga mat. Mom was at work, dad was making dinner. Then when grandpa finishes with the yoga mat, he goes into the living room to dance. The kid follows him to finish his homework.

I'm now convinced that something in the homework tuning has them seek out other people to be with when they do their homework.

In my dorms I always have a central study with a large table where everyone can do their homework, computers and bookshelves.

I assign all the beds and lock all the bedroom doors so that only the sims who sleep in each room are allowed to enter that room.