What is the difference between carpet area, built-up and super built-up area?

The area of an apartment or building, not inclusive of the area of the walls is known as carpet area. This is the area that is actually used and in which a carpet can be laid. When the area of the walls including the balcony is calculated along with the carpet area, it is known as built-up area. The built-up area along with the area under common spaces like lobby, lifts, stairs, garden and swimming pool is called super built-up area.