Making straght corridors will force you to sell all the mood at one time. Add way more turns, make it more unique and explorable. Remember that you're making a game and you can't just copy/paste original floor plans form real buildings. Also it's very typical and a bit lame to start a player's exploration in toilet. Your plan should tell where and why he is, how he will move from one place to another, what he will find. Also don't count that player will visit all the rooms and look on stuf you did there. Most of the players will jus run through objectives so make a player's way filled with decoration and avoid dead ends.
EDIT:
Lunaran already covered some of that tips in his article:
[Blocked Image: http://lunaran.com/images/dmenc/styl05.gif]
I like the architecture! Floor color is way different than others but I think it's not an issue, it will be good for guiding player I guess.
I think everything what reminds his favorite activities will be good. My uncle died in a fire few days ago. My mother left him a prayer-book. She thought that he'll need that where he's going. He still lives in the memories but there's lot of things that I wanted to tell him. Maybe try writing a letter to your friend?