Floor Space Index/ Floor Area Ratio- Importance, Calculation, Advantages, Disadvantages

The maximum area we can construct in a piece of land or a plot is known as Floor Space Index (FSI) or Floor Area Ratio. It can be further said as it is the ratio of the floor area of the building we are going to construct ie. build area of the building to the total plot area of the land.

The value or the ratio we receive, tells us how much area we can construct on each floor of the building.

Regulation Bodies

The state government is the regulating body under which municipal corporations or the local bodies carry out the work. The norms of FSI/FAR are set by considering the National Building Code (NBC) of India.

It is the regulating bodies, who provide the FSI which varies based on different cities, building structures, and other amenities.

How to calculate FSI/FAR.

Calculating FSI

Consider land area = 10000 sq.ft

As we have seen FSI vary on the different building structure, Location & floors, So firstly we have to consider the type of building i.e

• Residential

• Commercial

Let’s assume the FSI for residential building is 1.45 in that location, So we can easily find out

                                                            = FSI x Land Area

                                                            = 1.45 x 10000

                                                            = 14500 sq.ft

This further can be explained as 14500 sq. ft is the maximum area we can construct in that plot. If we are planning to construct 2 floors,

Then, 14500/2 = 7250 sq.ft each floor.

If we are willing to construct for three floors then

Then, 14500/3 = 4833.33 sq.ft each floor

Premium FSI –

Premium FSI is, the extra money we pay to the government resulting in receiving extra FSI or more plot area for the construction of the building. The Premium FSI can only be availed to the buildings which are near to the road at least 30 ft.

The % of premium FSI availed based on building location to the road can be defined as

Abutting Roadways	Premium FSI
1. 30ft – 40ft	20%
2. 40ft – 60ft	30%
3. More than 60ft	40%

 

Advantages of FSI

·         Planned Growth.

·         Clear view of open area and build-up area in the plot.

·         Equilibrium between open area and build-up area, resulting in reducing congestion.