Floor Space Index (FSI)

Floor Space Index (FSI) and Floor Area Ratio (FAR) are commonly used in the real estate sector.

It is the proportion of total built-up area to the available plot area.

The National Building Code is usually used as the basis for FSI standards.

In this article you’ll learn:

  • What is FSI?
  • Factors affecting the FSI.
  • Merits and Demerits FSI.
  • Lots more.

So, if you’re ready to go with the FSI, this article is for you.

Let’s dive right in.

What is the Floor Space Index (FSI)?

The Floor Space Index (FSI) is often referred to as the Floor Space Ratio (FAR).

It is the ratio of a structure’s total floor area (Built-up area) to its entire plot area (land).

This numerical value represents the total amount of area (on all floors) that may be built on a property.

Floor Space Index (FSI)

Importance of FSI In Building Construction:

  • The FSI or FAR value has an effect on the land value in a particular region.
  • It assists in determining the permissible dimensions of land, such as size and width, which can then be used to estimate how much land is used.
  • The FSI value does not remain constant across all places; it varies by region.
  • If the government raises the FSI or FAR values, the possibilities of improved usage, dwelling units, and space grow as well.
  • It contributes to the property’s price.
  • Because of the construction company can construct more, the builder will sell more and, as a result, the property buyer will pay acceptable costs.
  • It enables you to develop the structure in accordance with the laws and norms.
  • If you have personal expertise with the Floor Space Index, the approvals and NOCs will not be queried if the building plan is developed with FSI in mind.

 Important terms in FSI:

Paid Floor Space Index:

 When a builder or contractor wants to expand their FSI limit, they may be required to pay a fee to the municipal authority in order to obtain an additional area to include with the aim of expanding the overall plot area.

What Is Premium FSI?

If the property is near a major roadway, the premium floor space index is employed.

 A separate premium floor space index is utilized based on the width of the road.

The minimum width is 30 feet.

Also, the following premium floor space index might be used, taking into consideration the various widths of the adjacent major road.

If the road width is between 30 and 40 feet, the builder can obtain a 20% increase in floor space index.

The builder can get a 20% increment in floor space index if the road width is around 30 and 40 feet.

The builder can earn an extra 40% FSI if the road width is larger than 60 feet.

This 20% larger floor area index shows that 20% more building can be done than the actual allowable limit.

Floor Space Index Formula:

It is controlled by the Development Control Regulation Department of a specific locality and the National Building Code of India.

Authorities will set the FSI value depending on city area, type of construction, and other features.

 Floor Space Index = (Total Floor Area of all Floors of Building / Plot Area of Building)

The building’s total floor area must fulfil the government’s Floor space index for the region.

Floor Space Index for Various Cities of India:


 The Floor Space Index in India’s main city, Mumbai, ranges from 1.2 to 3.5.


 The Floor Space Index approved varies from 1.33 to 1.83.

The Mumbai Municipal Corporation allows an FSI of 2.5 for land parcel development under the MHADA, and 2.5 plus incentives for renovation.

The Maharashtra government has authorized an additional 0.5 FSI in exchange for a premium.


The FSI limit for residential developments in Kolkata is now between 1.5 and 2.5, as per the New Town Kolkata Building Rules, 2009.


The state of Hyderabad has not implemented any FSI limitations.

However, the municipal corporation & urban development (MA&UD) department in Telangana, on the other hand, is discussing reintroducing the floor space index (FSI) requirement for high-rise developments.


 According to the Haryana Urban Development Authority’s official website, the permitted floor space index in Gurgaon ranges from 1 to 1.45.

For industrial installations, the maximum FSI value is kept at 1.25. Construction is also allowed to have an FSI of 1.5 for public structures.


The value of the Floor Space Index is set between 2.75 and 3.5 for the Delhi-UP developed area in Noida and Greater Noida, which has seen significant housing demand, and collective apartment buildings are allowed a FAR of 2.75.

Equity investments have a maximum FAR of 1.5, whereas commercial buildings have a maximum FAR of 4, based on storey characteristics and ground covering.


According to the Draft Development Control Regulations for Proposed Development Pune, Pune authority allows an FSI of 1.5 to 2.5, depending on a variety of factors, and a maximum FAR of 5.5 for slums.

Factors affecting Floor Space Index Value:

Local municipal corporations set the FSI/FAR value. The value of the allowed floor space index (FSI) ratio is determined by:

  • The density of the population
  • The plot’s size
  • The existence of open places
  • Power, water, and sewer lines are all accessible.
  • Type of construction
  • The project’s environmental impact
  • In the case of a natural disaster, be prepared.

Advantages of Floor Space Index:

  1. In a city or a site where construction is constantly moving, the premium floor space index is used if there is a wide major road adjacent to the property.
  2. The open space-to-built-up-space ratio is maintained through FSI.
  3. It has command over the city’s skyline.
  4. It facilitates urban development. It implies that resources in the city are used efficiently.
  5. It prevents the development of structures that are illegal or unauthorized.
  6. It improves city planners.
  7. It maintains the city’s appropriate layout. plot.
  8. It is in charge of pollution.

Disadvantages Of Floor Space Index:

  1. It is assumed that FSI is a poor predictor of physical condition.
  2. The population’s wages and employment opportunities are affected by the FSI’s lower value.
  3. The Floor Space Index’s mean value can be turned into an asset, allowing the final product to be shaped to resolve all of the difficulties.
  4. Reducing the Floor Space Index (FSI) inhibits the city’s development.
  5. If the Floor Space Index is too high, the city may develop in an unsustainable and unplanned manner.
Also read:  Town Planning | Carpet Area |  Valuation of Building


The lowest FSI among mega-cities is in India, resulting in a discrepancy in the amount of land accessible for development and potential.

With the increase in FSI in the real estate industry, there is the potential for massive increases in real estate investment in India to enable better development of our cities

The appropriate kind of infrastructure development that will be able to sustain our cities for a longer period of time.

However, the need is for government to not only calculate the potential for an increase in FSI but also to ensure that government resources are utilized in the process of Increasing the availability of the same in the zones.

They wish to change resulting in a greater increase it as they increase development in other parts of the city.

Floor Space Index (FSI) will be a critical factor in India’s capability to shelter its very young population while also ensuring that they have plenty of job possibilities in their immediate area.

 If the existing technique of horizontal expansion continues, cities will become far too large for their infrastructure to keep up, and any upgrades to the infrastructure will be harder to accomplish in order to support increasing the FSI late.

Hello, I'm Rahul Patil founder of Constructionor.com, I had studied B.E. Civil. This blog provides authentic information regarding civil structures, equipment, materials, tests & much more.

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