FSI is one of the most important aspects of the real estate industry. This is the floor space index sometimes called the floor area ratio (FAR). Refers to the greater area of a piece of land used for development.This development is coordinated by the National Building Code of India and the Development Control Regulatory Department of each region, which is generally based on the Building Code. The floor space index is an important factor in regulating construction activities in urban areas.Areas covered by stairwells, lifts, corridors, architectural elements, and high cisterns (the height of the bottom of the cistern from the floor is not more than 1.5 meters) and terrace lap wc above the upper floor with a floor area not exceeding 10 square meters. Stairways and lift rooms, as well as passageways to basement level or parking decks. Parking area on the top floor or ground floor. Watchman cabin and crew quarters on ground floors or stilt parking lot.