The living quarters at Omni are geared towards serving the needs of those most comfortable in each element.
Fire (Ignis), Earth (Terris), Water (Aquis), and Air (Nitris) were the first elements represented at the original academy. Aeons later, Wood (Arbis) was added. Most recently, Metal (Platen) was added -- the baby among the elements.
Aether, of course, remains beyond the realm of the senses, as it always has.