Have you ever wondered why understanding the terms in real estate is very important?
When buying or selling a property knowing the terms with in-depth knowledge is a must. It will also apply to property developers. One of the important terms in construction is FSI (Floor Space Index).
Let us see the brief explanation of FSI in this article.
What is the FSI – Floor Space Index?
FSI, simply known as Floor Space Index. It is a crucial parameter in urban planning and construction. It governs the maximum floor area constructed in a given plot. FSI is expressed as a ratio of the total floor area of a building to the total area of the plot.
For instance, an FSI of 2.0 means that the total floor area can be twice the size of the plot area.
Every state has its unique rules and regulations for FSI. The population density and urbanization of a particular area define its FSI.
It can be divided into two categories namely High rise and Low rise.
Both had their unique limits and privileges. FSI helps in governing urban development. Sticking to the limits of FSI helps in commanding building density and infrastructure, and maintaining the overall plot area.
Here’s a table specifying the FSI limits by Brick & Bolt:
| Category | FSI Limit | Description |
| Residential (Low-rise) | 1.0 to 1.5 | Suitable for single-family homes or low-rise apartments with 1-3 floors. |
| Residential (High-rise) | 2.0 to 3.5 | Applicable for multi-story residential buildings with more than 3 floors. |
| Commercial (Retail) | 1.5 to 2.5 | Ideal for shopping centers, malls, and standalone retail outlets. |
| Commercial (Office) | 2.5 to 3.5 | Designed for office buildings, business parks, and corporate headquarters. |
| Mixed-use Development | 2.0 to 4.0 | Combines residential, commercial, and retail spaces in a single development. |
| Industrial | 1.0 to 2.0 | Suitable for manufacturing units, warehouses, and other industrial facilities. |
As we operate in various cities across India, each with specific Floor Space Index (FSI) limits, here are the FSI limits for some key cities:
| City | Area | FSI Limit |
| Bengaluru | Central Business District | Up to 4.0 |
| Other areas | 1.5 to 2.5 | |
| Mumbai | General residential areas | 1.33 |
| Bandra-Kurla Complex, Nariman Point | 3.5 to 5.0 | |
| Chennai | Residential buildings | 1.0 to 1.5 |
| Commercial buildings | Up to 3.0 |
Calculation of FSI
For building a sustainable and well-planned construction, adhering to FSI regulations is necessary. For performing the calculation of FSI, you need a simple FSI formula.
{FSI= Total covered area/ Plot area
FSI= 1000 square meters/ 500 square meters
The FSI value is 2}
From the above formula, the resolved FSI value is 2. And so the total floor area should not cross twice the size of the plot area.
Exemptions from FSI
As per governing rules, some parts of the building construction are exempted. They include stairways, lift rooms, Water closet areas, high tanks, unique structures, and passages.
It can also apply to parking areas, caretaker rooms, watchman booths, and facilities for servants and drivers. These exemptions cannot impact the calculated FSI value.
What is Premium FSI?
Premium Floor Space Index is the additional construction floor area that can be purchased from the local municipal corporation. If developers exceed the standard FSI limits set by the local authorities, it enables them to add more floors or build additional space on smaller plots of land. Even if you need to add more floors on small land, you can apply for Premium FSI. The Municipal Corporation uses this fund for further infrastructure development of government authorities.
How to Apply for Premium FSI:
Step 1: Developers must submit a formal application to the local municipal corporation, detailing their project and the additional floor area required.
Step 2: Upon approval, developers are required to pay a premium fee to the municipal corporation. The fee structure and rates vary depending on the location and the governing body’s policies.
Even with Premium FSI, developers must comply with all other zoning laws, building codes, and safety regulations.
The additional floor area should not compromise the structural strength of the building or the quality of life for residents.
Calculation of Premium FSI
First, calculate the standard FSI value by multiplying the plot area by the FSI limit
FSI= Plot area x FSI limit
FSI= 500 square meter x 2
Standard FSI= 1000 square meters (twice the size of the regular plot area)
Premium FSI= Total FSI – standard FSI
Premium FSI= 1500 square meters- 500 square meters
Premium FSI= 500 square meters
You may pay the additional fee for the Premium FSI of 500 meters.
Benefits of FSI
The key advantages of FSI are as follows:
- Estimate the potential development of the plot area or building can be concluded using FSI. You can also measure the key performance of the plot or the building and the future investment plans.
- Must follow the local municipal guidelines rules and regulations for building construction to avoid penalties.
- FSI helps in utilizing the spaces wisely.
- It can also be important for urban development.
- For investment and construction plans it can be a base for decision-making.
Challenges in FSI
The five important factors that affect the Floor Space Index (FSI) are as follows:
- Regional Rules:
The local municipal corporation sets the regional FSI rules and regulations. They are the authorized persons to handle construction-related work. They define FSI limits, height restrictions, land use, and building works.
- Infrastructure:
The FSI limit directly affects the infrastructure of the building. It impacts the nearby areas covered under the FSI limits.
- Environmental factors:
Factors such as open space requirements, gardens, and other ecological parks can affect FSI. The authorities have the right to deny or support the natural resources.
- Road facility:
The small narrow road and the larger building setbacks greatly affect the FSI limit.
- Type of the Building:
Different buildings have different FSI limits. Industrial, commercial, and residential type of buildings affect the FSI limits largely.
Conclusion
In conclusion, the increased FSI limits allow the developers to build more new constructions. It also supports renovations of old buildings into new properties. The Premium FSI allows anyone to extend their land space and construct more buildings. It plays a vital role in the decision-making process for an investor, a builder, or a buyer.
FAQ’s
FSI in simple terms means Floor Space Index.
FSI in common means maximum permissible area whereas Premium FSI means additional space purchased from the authority.
It defines the total floor area cannot exceed the limit of twice the size of the plot area.
For residential buildings, the maximum construction area FSI is limited to 2.
The simple formula for FSI calculation is given below:
FSI= Total covered area/ Plot area
FSI= 1000 square meters/ 500 square meters
The FSI value is 2.