the Empire State Building which has an FAR of 25 - meaning that it earns considerably greater rent than a newer building on the same land could hope for. Purpose and use The floor area ratio (FAR) can be used in zoning to limit urban density. While it directly limits building density, indirectly it also limits the number of people that a building can hold, without controlling a building's external shape. For example, if lot must adhere to a 0.1 FAR, then the total area of all floors in all buildings on the lot must be no more than one-tenth the area of the parcel itself. In other words, if the lot was 10,000 sq. ft, then the total floor area of all floors in all buildings must not exceed 1,000 sq. ft. An architect can plan for either a single-story building consuming the entire allowable area in one floor, or a multi-story building that rises higher above the plane of the land, but which must consequently result in a smaller footprint than would a single-story building of the same total floor area. By combining the horizontal and vertical limits into a single figure, some flexibility is permitted in building design, while achieving a hard limit on at least one measure of overall size. One advantage to fixing this parameter, as opposed to others such as height, width, or length, is that floor area correlates well with other considerations relevant to zoning regulation, such as total parking that would be required for an office building, total number of units that might be available for residential use, total load on municipal services, etc. The amounts of these things tend to be constant for a given total floor area, regardless of how that area is distributed horizontally and vertically. Thus, many jurisdictions have found it unnecessary to include hard height limitations when using floor area ratio calculations. Common exclusions to the total calculation of square footage for the purpose of floor area ratio (FAR) include unoccupied areas such as mechanical equipment floors, basements exclusively used for parking, stair towers, elevator shafts, and parking garages. Japan Japan has extensively adopted the floor area ratio in the zoning system since 1970. India In India FAR and FSI are both used. FAR regulations vary from city to city and generally it is from 1.3 to 3.25. In Mumbai 1.33 is the norm but higher FSI