All About FSI in Mumbai and Its Benefits


The Floor Space Index(FSI) is a popular parameter in the real estate industry. Read on to learn more about FSI in Mumbai

The Floor Space Index (FSI) is a generally used parameter in the real estate sector. The FSI Standards are designated to control building height in urban regions.

FSI is also significant for a redevelopment project to find out how much Floor Space Index it will need and require so that architects and developers can plan the project properly concerning space requirements and construction techniques. Read on to learn more about FSI in Mumbai, how it is calculated, and the new rules of FSI in Mumbai.

What is a Floor Space Index?

FSI, or Floor Space Index, is an urban planning mechanism that specifies the bulk, or volume, of a building. It is typical worldwide under various names, e.g., FAR (floor area ratio) in the US or coefficient d’occupation des sols in France. While it is frequently interpreted as a height restriction, it is more precise to see it as determining the volume of a building. The Floor Space Index of a building is the ratio of the total built-up area divided by the plot area.

For example, let us consider a Floor Space Index of 1. It means the city has a Floor Space Index of 1; then, it can build only one floor on a plot with no open space. Otherwise, two floors can be built if half the plot is kept open. Therefore, FSI is not specifying the number of floors but the quantity of floor space that can be built.

Most of Mumbai had a low Floor Space Index of 1 in the suburbs and 1.33 in most cities. But over the previous half a century, FSI has become a versatile and financialised instrument in Mumbai. The policies for FSI for residential buildings in Mumbai are specified by the area’s government and follow the National Building Code for the whole process.

New Definition of FSI

In 2018, a new definition of the Floor Space Index was added to the Development Control & Promotion Regulation-2034 (DCPR), which the Municipal Corporation of Greater Mumbai published. This definition contradicts what was delivered under the MRTP Act of 1966 and the National Building Code of India.

This act defines Floor Space Index as the total area on all floors, comprising the built-up area to the area of the plot. But the Bombay High Court in 2022 asked Brihanmumbai Municipal Corporation (BMC) to explain what it meant when it declared that the additional FSI would be utilised under the DCPR-2035 (Development Control and Promotion Regulation).

New FSI Rules in Mumbai For Redevelopment

The Government of Maharashtra put up the Floor Space Index to four from three state-wide rehabilitation schemes for slum regions in February 2022.

The highest FSI allowed in Mumbai before significant adjustments to the laws for development control over the last few years was 4.5.

A 2018 survey by the UN ranked Mumbai as the seventh most populated region in the world, with more than two crore people living in the metropolitan areas. This indicates that it is essential to build extra dwelling space in this metropolis where finding ground is very hard, and there is a requirement to build extra dwelling space.

What are the Impacts of a Very Low or High Floor Space Index?

A low Floor Space Index is seen as a restrictive law, and a high FSI as a liberal. This is because the Floor Space Index levels are, in theory, associated with urban density, housing supply, and housing prices. But in practice, other guidelines, floor space consumption per person, and a city’s history and demographics interact with the floor Space Index’s level to impact housing supply and urban form.

For example, a high FSI is deemed to result in a higher density or higher population. But in Mumbai, it has been discovered that Floor Space Index and density are unrelated. More and more floor space has been built in the last two decades in Mumbai, but the population has remained the same, and rates have skyrocketed. Thus the connection of FSI to the urban housing market is hard to pin down.

Evolution of FSI in Mumbai

The control over building heights began very early in Mumbai, as early as the mid-seventeen hundreds, as a simple standard that you can only create up to x meters or x floors. Then, the colonial government restored its attention to building heights. It emerged in its modern form, as Floor Space Index, in the late 1950s; the prime moment being 1964 when the 1.33 was determined.

Over a while, the government started granting FSI individually as inducements for urban development objectives. It developed into a hybrid and flexible policy incorporating the standard (in meters or floors), extra FSI that developers could reimburse for, tradable rights, and government concessions. The significant historical occasion that financialised Floor Space Index in Mumbai was the introduction of TDR (Transferable Development Rights) in 1991.

How to Find FSI of Any Land?

The city’s municipal corporation determines the premium Floor Space Index rate in Mumbai. Some of the significant factors that help the municipal corporation in Floor Space Index calculation in Mumbai are

  • Size of the property,
  • Type of building,
  • Building’s location,
  • Availability of luxuries.

The FSI value of various properties in Mumbai can be equal if the building size varies visually. Based on the new rules of FSI in Mumbai, it can be assessed by dividing the total area of the building floor by the plot area.

The Floor Space Index of a place can vary significantly based on specific factors. Generally, the deemed factors include parameters like population dynamics, construction exercises, growth models, and the nature of the space. Even the kind of land can significantly affect FSI value depending on whether it is an agricultural, residential, commercial, or industrial plot.

Floor Space Index in Mumbai is considered one of the significant factors for the city’s growth. A low barrier is a real estate limitation as it complicates the construction procedure. The real estate enterprise wants a higher FSI for the lands to prolong direct advantages for the estate developer.

How Much is FSI Allowed in Mumbai?

The Mumbai government pursues a transit-oriented development strategy. This allows the Mumbai government to keep the maximum Floor Space Index in the city at five. As per the new rules of FSI in Mumbai for redevelopment 2022, Mumbai’s Floor Space Index is up to five. The FSI score of the regions of Mumbai can be categorised as follows:

Width of the road (in meters), Minimum size of the plot (sq. m.) Maximum FSI in Mumbai Permissible
9 – 12 m Below 1,000 2
12 – 18 m Above 1,000 2.5
18 – 24 m Above 2,000 3
24 – 30 m Above 3,000 3.5
30 m and above Above 4,000 4-5

FSI for Cluster Redevelopment in Mumbai

A cluster redevelopment strategy is now authorised on roads with a minimum width of twelve meters; however, the route must be an arterial road within five-hundred meters of a highway with a nominal thickness of eighteen meters. The minimum size of the site and construction age requirements for the suburbs of Mumbai is six thousand square meters and thirty years, respectively.

Under section 33(9) of the rehabilitation program, dilapidated surrounding layouts are combined for redevelopment. However, as per the FSI, only permitted up to four. The amount of Floor Space Index shared with MHADA is based on the amount of FSI the community utilises.

What is TDR?

TDR is a kind of credit brought about when state-mandated urban development actions are carried out. For instance, if a developer builds slum redevelopment apartments, the government will award the developer a certificate of DR (development rights) rather than a payment. These development rights can then be used as additional FSI on the same plot, on the developer’s other projects, or sold in the TDR market.

Does FSI Influence the Size of New Houses Built?

Floor Space Index policy does influence the size of new houses, but in different means. For example, the redevelopment of slums in Mumbai is linked to TDR and FSI policy. These are flats where former slum-dwellers lived. The congestion in some areas like Juhu or Khar has been related to the TDR policy; these are more upper-class or middle-class flats and developments. As Floor Space Index premiums are a part of government income, Mumbai residents might be influenced by them in ways they are unaware of.

What are the Benefits of the FSI?

The Floor Space Index may be considered a significant real estate limitation, but it has several benefits for a progressing city like Mumbai:

  • Managing the city’s space and ecosystem.
  • Assess a project’s stable development
  • Operating the ratio between open space to developed space to an optimum degree.
  • Managing the adequate balance between supporting planned growth, and development is essential.

The planning authorities of the city purpose for the entire redevelopment plan with a move of FSI growth in Mumbai. Recently, the FSI base in Mumbai is 1.33, which has been raised to five for commercial and three for residential spaces after the government’s revision. While the Floor Space Index for commercial development in Mumbai suburbs has been increased to five, the Floor Space Index for residential spaces stays unchanged at 2.5. The FSI for commercial structures has been correlated to the width of the road, which means the more comprehensive the road, the more space can be utilised. This is the road width of Floor Space Index Mumbai.

The new regulation will lead to a rise in the development of Mumbai. Floor Space Index in Mumbai is the maximum permissible area authorised by the Municipal Corporation for development. However, per the guidelines set by the government, these parameters change from time to time.


Floor Space Index, or FSI in Mumbai, is used to control the heights of buildings. In Mumbai, Floor Space Index is amended every few years, and for owners in Mumbai, it is essential to stay up to date with the latest guidelines and new rules of FSI in Mumbai. FSI Mumbai is a very significant parameter for the government to track the growth and development projects in the city.

The government requires to track these details as any city has restricted space. With such limited space and a growing population, the government keeps track of the Floor Space Index value. With several developing areas, Mumbai is one of the most preferred cities among the new generation.


How can I buy FSI in Mumbai?

Paid Floor Space Index in Mumbai is available with the Planning Authority per the FSI rules in Maharashtra. Currently, Mumbai’s paid FSI charges are assessed depending on the ready reckoner prices of a plot. Therefore, paid FSI in Mumbai equals the undertaking’s 25-33% value.

What is the FSI for redevelopment in Mumbai?

According to the new Floor Space Index rules in Maharashtra 2022, FSI for redevelopment in Mumbai is the same as the regular FSI, which is 1.10

Are balconies and common spaces included in FSI?

No, the Floor Space Index calculation in Mumbai only takconsiderse gross floor area and hence does not include any balconies, common areas, exterior spaces, and driveways.

What is meant by permissible FSI?

The permissible Floor Space Index refers to the maximum floor region officially permitted to be developed. The permissible FSI differs for different properties based on location.

What is permissible FSI in Mumbai suburbs?

The private buildings in the suburban regions will receive a 2.7 Floor Space Index with fungible, while cess and slum buildings will receive a 4.05 FSI with fungible.

How can one increase the FSI?

The stretch between the land’s neighboring road and this Floor Space Index must be thirty feet. Suppose the property’s land site has a road that is thirty to forty feet away. In that case, you are eligible for the twenty per cent premium FSI, which allows you to construct twenty percent more than is legally permitted.