What is FSI

 F S I 

Floor space index- The ratio of the built-up space on a plot to the area of the plot is a regulation followed in the development control norms of many cities.

Floor Space Index directly tells us about the maximum permissible floor area that can be built on a plot. Numerically, Floorspace Index is the ratio of building floor covered area to the raw area available on that plot/land.

The floor space index value is changed from place to place. It also depends on the type of building. The Floor space index ratio value of a specific area is easily found in all the building bylaws for various cities and municipalities. Different cities or municipalities may have different bylaws and consequently different values.

Permissible FSI value depends on-

Size of the plot.
Type of building. 
The width of the adjacent road.
 Availability of power, water, and sewer lines. 

 Calculate FSI For Building :

FSI regulates by the Development control regulation department of a particular location and according to the National Building Code of India.

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

Why it is important to calculate FSI :

Floor space Index is very important for any building; it allows you to construct the building as per rule and regulatio

If the building plan is prepared with knowledge of FSI, the approvals and NOCs will not be questioned if you at the first-hand know Floor space Index.

Paid Floor Space Index :

Sometimes when builder or contractor wants to increase their FSI limit, they have to pay some fund to the municipal body to get an additional area to include with the aim to increase the overall plot area is typically termed as Paid Floor Space Index.

Floor Space Index for various Cities :

Hyderabad : Hyderabad state has not put any FSI restrictions. The municipal corporation and urban development (MA&UD) department is, however, considering the reintroduction of floor space index (FSI) norm for high-rise buildings in Telangana.

Mumbai : The permissible Floor Space Index in the Mumbai city is 1.33 to 1.83.The Maharashtra govt. has approved an additional 0.5 FSI on payment of a premium.

Advantages :

*It helps to maintain the ratio of open space to built-up space in an area.
*It ensures a clear skyline to the area.
*Good FSI values ensure good development of the project.
*It helps to Maintain equilibrium between sustained, planned growth and development is   important.              

Disadvantages: 

*Lower Floor Space Index leads to restrictions on the development of the city.

*If the Floor Space Index is too high, then it results in a non-environment friendly and haphazard development of the city.