In this method, the plinth area should be calculated by taking the external dimensions of the building at the plinth. Courtyards and other open areas should not be included in the plinth area. It consists in working out the plinth area of the building which is multiplied by the plinth area rate to get an estimate for the building.
The plinth area rates are generally provided can be deduced from the cost of similar buildings constructed in the same locality, having more or less the same finishing and same amenities.
The height of the building considered must be the same and must have need constructed during the same year of construction or a little earlier so that there should not be many variations in the cost of construction.
The plinth area is the built-up area or external dimensions of a building. In other words;
Plinth area = Carpet area + Circulation area + Kitchen/toilet + Walls Plinth area = Carpet area + 30% to 40% of total area for circulation and walls
