Carpet area is the useable area of a house which does not include the walls, pillars, or the balcony.

Built Up Area is the carpet area plus the thickness of outer walls and the balcony. It includes areas like, balcony, terrace and utility. Walls which are shared with other units are also taken into consideration at 50 per cent.

Generally, the Built Up Area is 10-15 per cent more than the carpet area. It is also called as the Plinth Area.