The apartments are separated by apartment but not floors or buildings. It's mix and match basically. You can have one apartment full of girls, while the apartment next door or across the hall can be full of boys. There are only two buildings that is separated (one building is for boys, while the other is for girls) and that is for super religious cps (mainly Mormons) who requests that.
Muchas gracias! I should have just looked at the pictures of the apartments that helped too!

Hows the scene there for those who are 21 and over?