How FAR/FSI is Calculated — Worked Example
FAR calculation: Plot area = 2,000 sq m. FAR = 2.5. Maximum built-up area = 2,000 × 2.5 = 5,000 sq m total across all floors. If ground coverage = 40% → ground floor footprint = 2,000 × 40% = 800 sq m. To use all 5,000 sq m, need 5,000 ÷ 800 = 6.25 floors → minimum 7 storeys required to use full FAR allowance.
FAR/FSI Norms Across Indian Cities
| City / Authority | Base FAR (Residential) | Premium/TDR FAR | Notes |
|---|---|---|---|
| Mumbai (BMC) | 1.0–3.0 (island city vs suburbs) | Up to 4.0 with TDR | Complex FSI rules by zone and road width |
| Bangalore (BBMP/BDA) | 1.75–3.25 (varies by road width) | Additional 0.5 for green buildings | Higher FSI on wider roads (>12m) |
| Hyderabad (GHMC/HMDA) | 1.5–4.0 (by zone) | Additional FSI in growth corridors | Among highest FSI in India for some zones |
| Delhi (DDA) | 1.5–4.0 (by zone and plot size) | 2.0 bonus for MIX use zones | Master Plan 2041 significantly increased FSI |
| Chennai (CMDA) | 1.5–2.5 | Varies by road width and zone | Lower than Mumbai/Hyderabad |
How FAR/FSI Affects Flat Buyers
Higher FAR means more units on the same land — which reduces each buyer's Undivided Share (UDS) of land. When comparing projects, check if one project uses significantly more FSI than another — the one with lower FSI per unit may be better for long-term land value. In redevelopment scenarios, UDS directly determines compensation — higher UDS means better redevelopment deal.
Related Terms
Frequently Asked Questions
FAR (Floor Area Ratio) — called FSI (Floor Space Index) in India — is the ratio of total built-up area to plot area. FAR = Total Built Area ÷ Plot Area. A FAR of 2.5 on a 1,000 sq m plot permits 2,500 sq m of total construction distributed across all floors. Higher FAR means more floors are permissible. FAR is set by the local planning authority and varies by zone, road width, and plot size.
FAR and FSI are the exact same concept — just different terminology. FAR (Floor Area Ratio) is the international term used in planning literature. FSI (Floor Space Index) is more commonly used in India — Mumbai, Bangalore, Hyderabad planning authorities use FSI. Both are calculated identically: total built area divided by plot area. When comparing international and Indian real estate terms, treat FAR and FSI as synonymous.
Higher FAR allows more total built area — which translates to more floors. If FAR is 3.0 on a 1,000 sq m plot, permitted built area is 3,000 sq m. With ground coverage of 40% (400 sq m footprint), the builder needs 3,000 ÷ 400 = 7.5 floors minimum to use full FAR. FAR determines density; ground coverage and setbacks determine the building footprint; together they determine the building height.
Premium FSI (or paid FSI) allows builders to purchase additional built area beyond the base FAR by paying a fee to the local authority. In Mumbai, builders pay a premium to the BMC to access FSI above the base. In Bangalore, premium FSI is available for wider road-facing plots. This additional FSI is used to add more units to a project, increasing the builder's saleable area and revenue.
Higher FSI on the same land means more units — reducing each buyer's Undivided Share (UDS) of land. A building using base FSI of 2.0 gives buyers better UDS than a similar building maximising FSI at 4.0. Lower UDS means less compensation in future redevelopment. Buyers in projects with very high FSI utilisation should factor in the reduced land share when evaluating long-term asset value.