What is FSI?

“Floor Space Index (FSI)” means the quotient obtained by dividing the total covered area (plinth) on all floors except the areas specifically exempted under these rules, by the Plot Area and is represented by this formula,

FSI = (Total covered area on all floors/Plot Area)

Spaces Excluded from FSI and Coverage Computation

The following shall not be counted towards FSI and plot coverage computation:

• In the terrace above the topmost storey, areas covered by staircase rooms and lift rooms and passages thereto, architectural features, elevated tanks (provided its height below the tank from the floor does not exceed 1.5 metres) and WC (with floor area not exceeding 10 sq.m).
• Staircase and lift rooms and passage thereto in the stilt parking floor or upper floors used for parking.
• Staircase and lift rooms and passage thereto in the basement floor or floors used for parking.
• Area of the basement floor or floors used for parking.
• Area of the stilt parking floor provided it is open on sides, and used for parking. In cases where the upper floor or floors over a stilt parking floor is proposed for parking.
• Servants or drivers' bathroom and water closet for each block in cases of Non High Rise Buildings and High Rise Buildings at ground floor or stilt parking floor.
• Watchman booth.
• Caretaker booth or room in ground floor or stilt parking floor.

Area of Special Character

Continuous Building Areas (CBA)

Buildings without side setback are permissible in a plot or site in continuous building areas set apart in the approved Master Plan or Detailed Development Plan or in the other areas as may be declared by the local body as CBA with the approval of the Directorate of Town and Country Planning or Government as the case may be from time to time. However in an approved layout area only in the plots classified for Continuous type of buildings it is permissible.

Economically Weaker Section Areas (EWS)

Areas declared as slum by Tamil Nadu Slum Clearance Board (TNSCB) are categorised as EWS areas for the purpose of these regulations. In addition it includes the areas developed as EWS plot in the Tamil Nadu Housing Board (TNHB) neighbourhood schemes, Sites and Services schemes, slum improvement schemes and approved layouts. For the purpose of application of these rules the Local body may declare areas as EWS Areas by council resolution and notify from time to time.

Coastal Regulation Zone (CRZ) Area

Developments in these areas shall be regulated with reference to the CRZ classifications and the regulations notified by the Government of India from time to time under section 3 of the Environment (Protection) Act, 1986 (Central Act 29 of 1986).

Conservation Zones in the Heritage Towns

Government may notify Heritage Towns, a list of Heritage precincts there in with metes and bounds and conservation zones around such listed Heritage precincts. Any new construction of building or use of premises in the conservation zones shall conform to the special guidelines relating to height, use etc., prescribed and notified by the Government from time to time.

Transit Oriented Development Areas

(i) In order to encourage Transit sensitive activities and to allow densifications in any mass rapid transit system in the state, the Govt. may prescribe such regulations, including premium FSI at concession rates as may be necessary from time to time.
(ii) In case of Metro Rail Corridors, Existing and Proposed properties located within a distance of 500m measured from the centre line of the corridor, Premium FSI shall be charged at 50 % of the normal Premium FSI rate.

Natural Hazard Prone Areas

(1) Areas likely to have (i) moderate to very high damage risk zone of earthquakes, or (ii) moderate to very high damage by cyclones, or (iii) significant flood flow or inundation, or (iv) landslides proneness or potential, or (v) tsunami proneness, or (vi) one or more of these hazards, have been declared as natural hazard prone areas.
(2) The areas prone to natural hazards will be notified by Government from time to time. Structural design and aspects of building construction in these areas shall take into the account of the special provisions contained in these rules for hazard prone area.

These regulations are essential for urban planning and ensuring safe, sustainable development while accounting for various socio-economic and environmental factors.

*Disclaimer:

The FSI Calculator provided on this website is a tool designed to assist users in estimating the permissible Floor Space Index (FSI) and related building parameters based on the inputs provided. The calculations and outputs are based on the regulations and guidelines available at the time of use. However, the accuracy and applicability of the results may vary depending on specific circumstances, updates to regulations, and interpretations by relevant authorities.

Users are advised to consult with qualified professionals and verify the results with local regulatory bodies before proceeding with any construction or development projects. Verified.RealEstate and its developers do not guarantee the accuracy, completeness, or reliability of the information provided by this tool and shall not be held liable for any discrepancies, errors, or omissions in the results.

By using this FSI Calculator, you acknowledge and agree to use it at your own risk and discretion.