Explanation Plinth area: ● It is the covered built-up area measured at the floor level of any storey or at the floor level of the basement. ● The plinth area is also called a built-up area and is the entire area occupied by the building including internal and external walls. ● It is generally 10-20% more than the carpet area. In the Plinth area Estimate, Open areas, courtyard, and balconies should not be included in the plinth area valuation. This method is also known as an approximate estimate.