How does FSI – Floor Space Index in Buildings work?

How does FSI - Floor Space Index in Buildings work?

In addition to the ‘Floor Space Index’, the FAR (Floor Area Ratio) measures the ratio between the area of the plot and the total built up area. Using this numeric value, you can see how much space you can divide up among different floors. As a result of height restrictions in that particular area, the city zone, land use patterns, special buildings, plot coverage, etc., the FSI for a particular zone can be found on the government’s website. FSIs range from 1 to 3 in residential land uses, and these values can be used on the ground floor if plot coverage, front and back setbacks, and open space reservations are taken into account. Floor space indexes are purchased after considering road width parameters in special cases when an ample amount of area needs to be constructed more than the available floor space index. These types of floor space indexes are called premium floor space indexes. According to the CMDA

  • An 18m-wide road would have a 40% width,
  • In the case of roads with a width of 12m or less, 30% would be applied.
  • In the case of roads with widths of 9m and less, the allowed FSI would be 20%

The Premium FSI is available only in specific areas; CMDA may vary rates and charges in different zones.


The zone in which you live has a FSI of 1.5 and a plot area of 2400 square feet

Step1 :You can build up to 3600 sq ft on your plot, but this area must be divided among different floors within this 3600 sq ft area.

Step 2: A building setback is based on the width of the road, the width of the plot, and the height of the building when planning it. These As a guideline, measurements will help you determine what the setback should be. In case of special construction, you will also have to take the OSR into consideration. The remaining area would be your left-out construction area.

Step 3 – Divide the buildable area into different numbers of floors (it is also important to consider height restrictions in the area).

Then you find out your FSI and distribute it accordingly according to your detailed requirements