I'd like to give my last list some order. There will be three floors to the keep: Cellar, Ground-Level, and 2nd Floor.

Cellar: Dungeons, Storage, Armory, Basements of Guardhouses and Towers, and Servant's Quarters

Ground-Level: Guardhouse, Kitchen, Great Hall, Well, Bathrooms, Stables, Chapel, Workshops, Tower Bases, Residences, Siege Workshops

2nd-Floor: Library, Bathrooms, King's Quarters, Balcony, Study, Towers, (?Magic Quarters?)

Outdoors: Walls, Machicoulis, Draw-Bridge, Moat, Tournament Grounds, Courtyards, Training Grounds

Lastly, towers might continue going up to four stories (including basement). Remember each story has a ceiling 20-feet high: that adds a lot of total height.