Floor Space Index: Know its Meaning & Importance & how is FSI Calculated

When selecting a property to live in, it is crucial to have a clear understanding of Floor Space Index (FSI), its meaning, and how it is calculated. This knowledge will help you assess whether the house size aligns with your requirements for an ideal home. FSI, also referred to as Floor Area Ratio (FAR) in some areas, represents the ratio of the total area covered by all the floors of a building to the total land area on which the buildings are constructed. The built-up area refers to the cumulative area covered by all levels within a building. Let’s delve deeper into this concept to enhance our understanding.

What is FSI?

Floor Space Index (FSI) is the total area a builder can use to build infrastructure on a particular piece of land. It can be understood as the ratio of the building floor covered to the area available on the land. FSI of a specific plot depends on the rules and regulations set by the city’s municipal authorities or the state’s administrative government. Hence, they vary from Location to location.

Furthermore, FSI of the same zonal areas will vary based on road width, plot size, etc. There are non-FSI areas defined by local authorities of specific zones. In some states, staircases, service rooms, parking areas, and open balconies are part of FSI. We must refer to the local building norms to understand the exclusions for FSI calculation.

Why is FSI Amended Regularly?

As the population in the country grows, especially in cities like Delhi, Mumbai, Chennai and Bangalore, there is a rising need for increasing urban housing – and in turn, the need to regularly amend the FSI. Many urban cities like Mumbai and Chennai have proposed to increase their FSI in the hopes to declutter the city, create more housing for their population, and making more space for green covers and other amenities.

What are the Benefits of FSI?

The Floor Space Index may be viewed as a limitation, but it offers several advantages in cities or other places where construction is moving very quickly.

• It keeps the proportion of constructed to open space constant.
• It keeps the city’s skyline intact.
• A project’s development is ensured by an average FSI value.
• It is critical to maintain harmony between development and planned
  continuous growth.

How is FSI Calculated?

Once you have grasped the FSI meaning, the next logical step would be to understand how to calculate FSI for a property. But before you learn how is FSI calculated, remember that the floor space index is commonly represented as a percentage, but the floor area is typically expressed as a ratio. In terms of the floor space index, a floor area ratio of 1.4 would be stated as 140 percent.The formula for FSI calculation:

Total Covered Area on All Floors – (non-FSI areas)
FSI =       _____________________________________________
Gross Plot Area

For instance, if the maximum allowed FSI in a zone is 1.5, and the builder has a 1,000-square-meter plot for construction, the builder will follow the DCR (Developmental Control Rules). The builder is then allowed to construct up to 1,500 square metres on this property. Depending on the style of construction and the number of levels allowed, this 1,500 sq. m covered area could be divided into two
750 square metres floors or three 500 square metres floors. The finished area would include the basic framework, walls, stairwells, and, if applicable, lobby space. This number is subject to fluctuation depending on the allowed FSI.

Permissible Value of the FSI and the Factors it Depends On

Once you know how FSI is calculated, the next step is identifying the permissible
value of the index in the city you wish to buy your property in. A building's FSI can be
affected by a variety of factors that include:

• The size of the plot
• The type of building
• Access Road
• The plot’s location (city zone), and
• The basic utilities made accessible for the building.

It is also important to note that the FSI of the land is often affected by its location.
The permitted FSI in developed areas may differ from the acceptable FSI in older
and established parts of the city. Depending upon the city’s development needs and
land value, each city usually updates the FSI value. The FSI number also determines
the plot’s potential and commercial value.

Make Informed Choices: Understand FSI Before Your Next Property Purchase!

Before buying a property, every homebuyer must consider several legal requirements and investigate the nature of certain construction restrictions. Understanding how FSI is calculated is one such crucial factor to be aware of. The area density of each property is defined by its FSI, or ‘in-construction’ designation.

A housing society will be able to build high-rise buildings if the FSI index is higher. A larger group of individuals will now be able to share the community’s amenities, such as the pool, gardens, elevators, electricity, water supply, etc. Similarly, a lower FSI index suggests fewer people will be using the same community amenities, making it a more comfortable environment for residents.

For individual houses, a higher FSI index indicates that the homebuyer has permission to construct a home with more usable space or storeys. With the knowledge of permissible FSI and how is FSI calculated, homebuyers can make better and more informed choices while purchasing property!

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