GWZ,

Habitable space;
IBC/IRC 2000-"A space in abuilding for living, sleeping, eating or cooking. Bathrooms, toilet rooms, closets, halls, storage or utility spaces and similar areas are not considered habitable spaces."
UBC 1997 - "Habitable space (room) is a space in a structure for living, sleeping, eating or cooking. Bathrooms, toilet compartments,closets, halls, storage or utility space, and similar areas, are not considered habitable space."