Iceberg homes have basements that may be significantly larger than the house on the surface. These basements can be as many as four storeys deep and allow for swimming pools, private cinemas, fitness areas, tennis courts...
It means the elite finds a way to evade surface regulations. Also, having a bunker at -4 is a protection against weapons of mass destruction, I guess.
Habitats on Mars probably will be iceberg homes, but now it seems that they are suitable for planet Earth as well.
SOURCE: Boss Hunting 
TAGS: ARCHITECTURE CLIMATE HOMES LIVING