What is FSI ( Floor Space Index)?

FSI ( Floor Space Index) or FAR (Floor Area Ratio) is the ratio of total built up area divided by the plot area.

FSI  = Built Up Area / Plot Area

FSI means  that how much area you can build up in a given plot.

Built Up Area= FSI x Plot Area

FSI is decided by the Directorate of Town And country Planning. It  varies from city to city and even can vary into different localities of same city.

FSI may also depend on the type of construction::

• Ordinary Building – This has maximum upto 2 floors and less than 4 dwelling units or flats
• Special Building – Your construction will fall into this type when it is more than 2 floors and not  more than 4 ,
• Multi-storeyed Building – These constructions are exceeding 4 floors

We also have Industrial Building, Group housing constructions, their FSIs  will vary as well.

Example of FSI calculation: For example if your plot area is 4000 sq feet and FSI is 1.5.

Built p Area = 4000x 1.5= 6000 Sq ft

Apart from FSI you also need to comply with other regulations of local authorites like

• Minimum plot extent area
• Front, back , side and rear setback
• OSR and parking space.
• Additionally if your plot is nearby airport you may have restriction regarding height of the building.

You can check the FSO fro your area on the state Government’s official website.

What is Premium FSI?

Premium FSIs are allowed as exception as permissible  deviations.

You need to pay premium to the State Government to avail the Premium FSI, Extent of  Deviation of   Premium FSI will depend on the width of adjoining road. You should have minimum 30 feet road  to avail the Premium FSI.

Some Examples::

• 30 – 40 Feet Road Width – 20 % Premium FSI
• 40 – 60 Feet Road Width – 30 % Premium FSI
• more than 60 Feet Road Width – 40 % Premium FSI

Example :: if you have a 40-60 feet wide adjoining road, you can avail the  Premium FSI up to 30%. In the above-mentioned case  the Built Up Area ca be calculated  as ::

Built Up Area= 4000 x  1.5 x (30%) + (4000 x 1.5) =4000 x 1.5 x  0.3 = 1800 + (4000 x 1.5)= 7800