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What is the Floor Area Ratio, and how do we calculate them?

Admin 21 Jun 2022 69 Views
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Regarding real estate and construction, each of us wants to build the best for ourselves or commercial sale purposes. Numerous technicalities come to light when we talk about the construction of a property. The land, material, and area, one of them is Floor Area Ratio, which we will discuss today. 

Often people new to construction or real estate buy a piece of land but have problems finding answers to their questions, the first of which starts from how much construction is legally allowed on the piece of land you bought? The answer is Floor Area Ratio. Enough with the build-up; let's get into details of the floor area ratio, floor area ratio formula, how to calculate floor area ratio, and more. Starting with:


What is Floor Area Ratio

Floor Area Ratio (FAR), also known as Floor Space Index (FSI), is the maximum permissible floor area (by the government) that you can build on your piece of land. It is the total constructed/constructible area in sq ft./sq m. to the total plot/land size. We know that might sound confusing, so let's break it up; given the name, the floor area ratio is a ratio between two different floor areas. Now, what areas are they? First, the total plot size, and second, the constructed buildings. Let's dig more into it with an example:


Consider Mr. Lee bought a 10000 sq ft. land in the suburbs and wants to construct a five-floor building over it. Now, although as high as his ambitions are, Mr. Lee has little idea how much floor area he is allowed to dedicate to each floor, but he remembers a simple floor area ratio formula that he learned from a friend. So, here's what Mr. Lee does, he checks the FSI or FAR decided by the city's government for the type of property he wants to construct, which, let's say, happens to be 2. 


Now that Mr. Lee has the FSI of 2, he applies this simple floor area ratio formula to calculate the floor area ratio of the building.


FSI = (Total Floor Area of Each floor x No. Of Floors) / Total Area of Plot

Putting in Mr. Lee's Value


2 = (Total Floor Area of Each Floor x 5 ) / 10000

Or Total Floor Area of Each Floor = (2 x 10000) / 5

Therefore, the total floor area of each floor that Mr. Lee is allowed to construct is 4000 Sq ft.


We believe that example would have made it easier to understand things for you.

 Steps Needed to Calculate Permissible Area of Construction

1. Find the FSI or FAR of the type of construction in your city, whether residential or commercial. (The government decides it)

2. Put the Values in the formula FSI = (Total Floor Area of Each floor x No. Of Floors) / Total Area of Plot

3. Check with local authorities for your construction plan.


Who decides the limit of Floor Area Ratio?

The floor area ratio varies from city to city and even area to area, depending on the rules decided by the local government. It can be higher or lower depending on the area, population density, soil quality, climate, etc. The Floor Area Ratio is generally different for Residential and Commercial buildings. 


Is the balcony included in the floor area?

You might be surprised that common areas and amenities like parking, common spaces, parks, sports courts, exterior/interior spaces, basement parking, attics, and balconies are not included in the floor area. This can give you much extra room to play with when you want to build the perfect construction. 


What is the ideal FAR?

As mentioned above, the local government decides on the FAR and FSI of your area. Therefore there is no ideal FAR. However, to be specific, people or real estate businesses generally go for FAR above 1.5; this gives them the room to create multiple floors with a larger build-up area and leaves ample space for amenities. In many areas, you might find the floor area ratio up as much as 2.5, which is quite a decent number if you imagine building construction over an area of 10000 sq ft. as Mr. Lee did above.


We hope you understand what Floor Area Ratio is, why it's important and how you can calculate it. Note the extra amenities and space you can use in your construction as it is not included in FAR. Getting an architect who can help you create a floor plan under the specified FAR can help you plan your construction.

About Author


Jatin Dubey

An enthusiastic content writer who is a law graduate and has been working as Real Estate Consultant for around 9 years.
He has worked with top Real Estate Agencies and Builders in Delhi, Bangalore and Pune. His skills to perform market analysis and explore high potential localities has helped many clients in the past.