@Seventeen I disagree with a few things.
First, making a Tower Room gives an inherent bonus to that room. This sort of mandates that our magical workshops should be all tower rooms.
Second, there's the quality of life issue: a penthouse with an amazing view beats a torch-lit bunker any day.
Ulgu itself requires the play between light and dark, so it benefits from sunlight.
Also, the higher we are, the farther we are from background magic "pollution".
Third, we absolutely should not delve so deep that we make another entrance into our home. The penthouse is fabulously secure by having all of one way of getting in: climbing a shitload of stairs, part of it in full view of the hold, and go through multiple doors.
Inviting random people into our sanctum is the last thing we ought to be doing.
I would say:
- Vault
- Library/Study
- Ulgu-rich tower room (5 college favors)
- Magically-neutral research tower room (X dwarf favors)
-- Add panic buttom to both.
It looks like two towers and two underground, but I think a study really need someplace aired and well lit, not dusty and stuffy.
With the main floor as living quarter. Later, after everything is built and furnished, add a bedroom at the top and transform the first floor into a living room.
I suppose we will have to build the first one, and see what options are open.
@edit: the autocorrect gets worse by the day.