Carpet area is the actual usable area of an apartment, office unit, showroom, etc. minus wall thickness. Carpet area is the area enclosed within the walls, actual area to lay the carpet.
This area does not include the thickness of the inner walls.
Build Up Area:
Built-up area is the carpet area plus the thickness of outer walls and the balcony.
Super Build Up Area;
Super built-up area is the built up area plus proportionate area of common areas such as the lobby, lifts shaft, stairs, etc. The plinth area along with a share of all common areas proportionately divided amongest all unit owners makes up the super built-up area.