Carpet Area, Built-up Area, Super Built-Up Area

Carpet Area: This is the area of the apartment that does not include the area of the walls and balconies.Carpet area of an apartment or building means the area that is actually used and in which a carpet can be laid. 

Built-Up Area: This is the area of the apartment that includes the area covered by the walls. Carpet area + Area of the balcony + area of the walls are known as built-up area.

Super Built-Up Area:  This term is only applicable for multi-dwelling units, such as flat complexes.The super built up area includes the built-up area + common spaces like lobby, lifts, stairs, garden and swimming pool etc.