Follow Us :

When starting construction of any residential or commercial property, one may encounter the term FSI. This article discusses the concept of FSI in detail.


FSI means Floor Space Index. It is also known as Floor Area Ratio. FSI is nothing but the ratio between the floor area of the building to be constructed and the total gross area of the piece of land on which it is constructed. Floor Space Index is regulated by the municipal or local authorities governed by the respective State Governments. These values are fixed and based upon the National Building Code which tells us about the maximum floor area which is permissible to be constructed on a piece of land.


The floor space index (FSI) measures the ratio of the building’s floor area to the total area of the plot or land.

The FSI value varies from city to city. The construction Bye-Laws for various towns and municipalities clearly list the FSI value of each region. The FSI value depends on the size of the plot, type of construction (business building, residential apartments, etc), the proximity of the development from the road.


The total floor area of each floor as well as the total area of the land plot is required in order to calculate the FSI.

FSI = Total floor area of the each floor / total area of the plot 


Let’s assume that you have a 2000 sq. ft. plot on which you want to build a 6000 sq. ft. structure

Then FSI = 6000/2000 = 3

Here FSI value is 3.

The municipal corporations and local authorities decide upon the permissible FSI in their respective jurisdictions. By considering the FSI set out by these local authorities, that we can also calculate the area of the entire floor.

Let’s assume the FSI is 1.5 and the total area of the plot is 2000.

Total area of all floors = 1.5 x 2000 = 3000

It can be 3 floor of 1000sq.ft or 2 floors of 1500 sq.ft or 1 floor of 3000 sq.ft


The FSI value affects the value of land in a specific location. This value helps the builders to know how much land can be used to build the property in that specific plot. A higher FSI for builders enables them to build more and sell more. A lower FSI would indicate that less area will be used for construction on that plot. The builder or contractor can pay the municipal body to increase the FSI value by adding additional area to the plot. It is known as Premium FSI.


Premium FSI is the increment in the permissible FSI which is only applicable if the land in consideration is located adjacent to a road and the adjoining road is at least 30 feet wide. When lower FSI is permitted by municipal corporations in any locality, the FSI can be increased in value by paying the necessary charges to the local authority.

If the road adjacent to the plot is 30-40 feet in width, then you can get a premium FSI of 20%. This means that you can build 20% more than the permissible FSI. Likewise, if there is a 40-60 feet wide road adjacent to the plot, then you can avail a 30% premium FSI. Similarly, for plots that are abutted with over 60 feet road, then the Premium FSI is 40%.

If the area total construction area of land is 2000 Sq. ft which is having 30 feet roadside length (where normal FSI is 1.5), you can take advantage of a premium FSI of 20% by paying the premium fee.

Build up area = 2000 x normal FSI x Premium FSI = 2000 x 1.5 x 20% = 600 square feet


  • IN DELHI: According to the updated Delhi Master Plan 2021, there will be a consistent Floor Area Ratio (FAR) for both residential and commercial structures. Previously the FAR for 100 sq.ft was 1.8 to 2.25 but it is now raised to 3.5 for 100 sq.ft of plot area. Normally it ranges between 1.2 to 3.5.
  • IN KOLKATA: The New Town Kolkata Building Rules, 2009 states that the FSI can range between 1.5 to 2.5 for residential buildings in Kolkata.  Like in all other cities, factors determining calculation of FSI in Kolkata also depend on the land use, road width, density etc.

All you need to know about Floor Space Index (FSI)

  • IN CHENNAI: According to Development Regulations 26 (Table A) of Chennai Metropolitan Area, the FSI in Chennai is 2.0 which is raised by 0.5 with retrospective effect from October 1, 2018.
  • IN BANGALORE: Bangalore is divided into three zones intense development, moderate development and sparsely development. According to Bangalore Revised Master Plan 2015, the FSI varies from 1.75 for smaller plots to 3.35 for larger plots, with factors influencing the FSI being area, building activity, plot size, and road width.
  • IN HYDRABAD: In Hyderabad there is no restriction of FSI. There is free FSI because it is to encourage developments in the city.

This blog is written by Varun Thokala, an intern of Smriti Legal LLP. 


Author Bio

Smriti Legal LLP is a sector focused law firm headquartered at Bengaluru with associated offices nationwide. The firm specializes in RERA litigation and legal advisory services under The Real Estate (Regulation and Development) Act, 2016 ( Contact: +91 97400 12005 View Full Profile

My Published Posts

Builders Ordered to Hand Over Common Areas to Homebuyers: KRERA TS RERA Circular Promotes Real Estate Project Transparency & Accountability Supreme Court Declares Homebuyers as Creditors under IBC Battle of Vahe Imperial Gardens: Consumers Triumph over Deceptive Real Estate Developer Enforceability of Circulars/Notifications: Publication in Official Gazette Explained View More Published Posts

Join Taxguru’s Network for Latest updates on Income Tax, GST, Company Law, Corporate Laws and other related subjects.

Leave a Comment

Your email address will not be published. Required fields are marked *

Search Post by Date
April 2024