Floor Space Index (FSI) or Floor Area Ratio (FAR) are significant words utilized in the sector of land . It is the ratio between the entire built-up area and therefore the plot area available. It is allowed by the govt for a specific locality. It primarily describes the ratio of the entire covered area of construction to the entire plot size. It is sometimes termed floor space ratio (FSR), floor area ratio (FAR), site ratio or plot ratio. FSI norms are normally based on the National Building Code.

Buildings with different numbers of stories may have equal FAR values. Every city has a limited capacity or limited space that can be used safely. Any use exceeding this limit sets unnecessary pressure on a city.

For a city or country, FSI/FAR value may be amended from time to time depending on the growth of each city, improved land value, power, water, and sewer facilities.

FAR is possible to differ because population dynamics, growth models, construction exercises, and therefore the nature of the land or space where a building is found differ. Industrial, residential, commercial, agricultural and non-agricultural spaces have different safe loading factors, so they normally have different FARs.

FAR is an important deciding factor for development in any nation or city. A low FAR may be a common barrier to construction. Many industries, mainly the important estate industry, want hikes in FAR to unwrap space and natural resource to developers. A raised FAR permits a developer to complete more building projects, which necessarily points to higher sales, decreased expenditures per project and extensive supply to match demand.

Key Outcome:
The floor area ratio is the proportion of the total usable floor area of a building related to the total area of the plot.
A higher ratio is indicative of a dense or highly urbanized area.
The FAR will differ based on structure type, such as industrial, residential, commercial or agricultural.
FSI in India’s top 10 cities:
As per the revised Delhi Master Plan 2021, uniform Floor Area Ratio (FAR) for both residential and commercial properties, permitting the regularisation of illegal construction. This means the FAR for 100 sq.m was earlier variable, varying from 1.8 to 2.25, but now it's approved to be a consistent 3.5 for 100 sq.m.

There is no FAR restriction on group housing projects while plots within the influence zones and Metro corridors are allowed a better FSI. Redevelopment projects in Delhi are provided an FSI value of 4.

 The residential FSI for the island city has been raised to three .0 and commercial to five .0 from 1.3 for both. In the suburbs, the FSI for residential projects has been increased to 2.5 from 2.0 and for commercial it stands at 5.0 as against 2.5.

As per the New Town Kolkata Building Rules, 2009, the range of FSI for residential buildings in Kolkata is between 1.5 and 2.5. The limit is fixed depending on the land use, road width, density, etc.

Recently, Kolkata civic body has made certain changes to the Floor Area Ratio (FAR) to allow the property owners to add an extra floor. This means that they will now get 3,000 sq ft extra space for construction, which is equivalent to the construction of an additional floor.

The real estate projects in Kolkata which are being developed within one kilometer of any metro line/route/corridor will have the eligibility to have a 20% higher floor area as compared to the floor area that was allowed previously. Apartments facing roads with width ranging between 15-24 m can apply for added floor area ratio to the tune of 15%. In the case of road width exceeding 24 m, this will go up to twenty . The floor area ratio is that the ratio of the gross floor space of a building to the plot size.

Recently, the Government of Tamilnadu has passed an order which states the permissible limit for FSI in Chennai is 2.0 which is a raise by 0.5 and it comes with retrospective effect from October 1, 2018. Though the rise in FSI won't be applicable in ecologically sensitive areas like Aquifer Recharge Area, Red Hills catchment basin , and Coastal Regulation Zone.

Construction of residential homes/buildings in Chennai, under Chennai’s 2nd Master Plan 2026 conforms to the FSI limit of 1.5 for normal residential buildings and 2 for high rise buildings.

As per Coastal Regulation Zone (CZR) 2011 Notification, the Floor Space Index (FSI) or the Floor Area Ratio (FAR) had been halted. On the other hand, in CRZ 2019 Notification, the state government decided to de-freeze the FSI and permit for construction projects.

After the implementation of the new General Development Control Regulations (GDCR) regulation which permits property owners and builders to redevelop buildings that are 25-meter high with higher Floor Area Ratio (FAR) along the roads which are less than 18-meter wide.

FSI within the prime localities of Ahmedabad is 1.2 while it goes up to 1.8 for localities within the suburbs.

Under the new rules, property owners will be granted a Floor Space Index (FSI) of 1.8 after which, they will have the option to avail paid FSI of up to 2.9, enabling property owners to reconstruct their old homes.

The proposed FSI ranges from 2 to 5 , relying on the size of the plot and thus the road and seeks to encourage vertical growth and wider open spaces within the form of setback areas. With this, properties along the Metro, suburban and bus corridors will enjoy the new policy.

New FAR For Residential Purposes:
Plot Size (Sq.m)

Road Width

Existing FAR

Permissible FSI



Up to 360

Up to 12 m





12 to 18 m





18 to 24 m





24 to 30 m





Above 30 m