Real estate developments in a city must adhere to several construction guidelines, including development control norms, to maintain uniformities in building constructions in a city. One way to achieve this is to set specific floor space index (FSI) norms for construction.
What is FSI?
FSI is the ratio of the floor area in a building to the area/size of the plot. For example, if a 2,000-sq-ft building stands on a 1,000-sq-ft plot, the FSI would be 200%. For a 3,000-sq-ft building on a 1,000-sq-ft plot, the FSI would be 300%.
Thus, FSI is the tool to control the densification and growth pattern of a city.
What is FAR?
Floor Area Ratio or FAR is the ratio of the floor area in a building to the area of the plot. For example, if a 2,000-square-foot building stands on a 1,000-square-foot plot, the floor area is 2. Similarly, if a 3,000- square-foot building stands on a 1,000-square-foot plot, the floor area is 3.
What is the difference between FAR and FSI?
FAR or floor area ratio and FSI are the same things but they are denoted differently. While the FAR is expressed in decimals, the FSI is expressed in percentages. The two are calculated using the following formulas:
FAR = Total floor area of all the floors of a building/plot area
FSI = Total floor area of all the floors of a building/plot area x 100
If the FAR for a city is 3, the FSI value would be 300%. This means that on a 1,000-sq-ft plot, you will be able to develop living areas of 3,000 sq ft.
What is Floor Area Ratio Formula?
The floor area ratio index formula is:
FAR = Total floor area of all the floors of a building/plot area
What is Floor Space Index Formula?
The floor space index formula is:
FSI = Total floor area of all the floors of a building/plot area x 100
What is the use of FSI?
FSI, also known as FAR (floor area ratio), is an effective tool to control real estate development. While higher FSI will lead to dense constructions, lower FSI would mean low to moderate crowding. FSI is effective in increasing revenues for urban-local bodies ─ the higher the FSI, the higher the revenue. People think of getting freedom from FSI because of some reasons
Who fixes FSI?
While complying with the central National Building Code, FSI is determined by the local municipal bodies or state governments.
What is the average FSI in India?
When compared to other megacities in the world, FSI values in India are low. In major cities, the FSI is between 1 and 5. The FSI varies from city to city, locality to locality, and building to building.
In Mumbai, for example, the FSI ranges between 2.5 and 5, depending on the exact location of the plot and land use.
See also: FSI in top Indian cities
Factors that influence FSI norms
- Development control norms
- Zone
- Building type
- Amenities
- Road width
Importance of FSI in construction
Building and development authorities of a country use FSI to determine and control real estate development, depending on their limitations and requirements. For instance, buildings in Mumbai are taller because of higher FSI when compared to most other cities in India. This is because being an island city, Mumbai has space limitations that don’t allow vertical developments. However, since the height of development can also pose safety risks, heights of buildings are control to maintain building safety using FSI as a tool to make a balance.
FAQs
What is FSI in construction?
FSI, short for the floor space index, is the maximum permissible area that a developer can build on a piece of land.
Who decides FSI?
Municipal corporations decide the FSI limit in a city. For example, The BMC decides the FSI for Mumbai.
