FSI and FAR Explained: What Bengaluru Buyers Must Know in 2026
FSI and FAR cap how much can legally be built on a plot. How the ratio works, how Bengaluru road width sets the limit under the BDA and BBMP master plan, what premium FAR and TDR are, and how to check a building is not over built.
A buyer looking at a smart looking five floor apartment block on a 30 foot road in East Bengaluru in September 2026 nearly booked before an architect friend asked a single question: what is the sanctioned floor area ratio for this plot? On a road that narrow, the permissible ratio allows far less construction than five full floors, and the top floor turned out to be built beyond the sanctioned plan. That one extra floor was the kind of thing that stalls an occupancy certificate and haunts resale. Understanding floor area ratio is how a buyer tells a legally built home from an over built one.
The short answer. FSI and FAR are the same thing, the ratio of a building's total floor area to the plot area, and they cap how much can legally be built on a piece of land. In Bengaluru, the permissible FAR is set by the BDA and BBMP under the Revised Master Plan and depends mainly on the width of the road abutting the plot, ranging from roughly 1.75 on narrow roads to around 4.0 on wide arterial roads. The trade off that matters to you is simple: a building constructed beyond its sanctioned FAR is unauthorised to that extent, which can jeopardise its occupancy certificate and its resale. Always confirm the sanctioned plan and FAR against what is actually built, using the BBMP and BDA framework as your reference.
What are FSI and FAR?
They are two names for the same ratio, the total built floor area divided by the plot area. Floor Area Ratio is usually written as a decimal, so a FAR of 2.0 means the total construction across all floors can be twice the size of the plot. Floor Space Index is the same concept sometimes expressed as a percentage, so an FSI of 200 percent is a FAR of 2.0. This single number governs how much building a plot can legally carry, which is why planners use it to control density, traffic and pressure on water, drainage and power. For a buyer, it is the number that quietly determines whether the building you are looking at could ever have been approved as it stands.
How is FAR calculated, with a simple example?
Multiply the plot area by the permissible FAR to get the maximum buildable floor area. If a plot is 2,000 square feet and the permissible FAR is 1.5, the total construction across all floors can be up to 3,000 square feet before other rules bite. That figure is a ceiling, not a promise, because setbacks, ground coverage limits, height restrictions, parking requirements and stilt rules all shape what can actually be built within the FAR. In practice a developer works out the buildable area from the FAR, then arranges it into floors and units within those other constraints. As a buyer you do not need to design the building, but you should be able to sanity check whether the built area plausibly fits the plot and its FAR, because a wild mismatch is a warning sign. A quick mental test helps. Take the plot area, multiply by the permissible FAR, and compare the answer with the total saleable area the developer is selling across all units. The saleable area will be larger than the pure FAR area because it includes common areas and loading, but if the built floors clearly imply far more construction than the plot and FAR could ever allow, that is a question worth pressing before you fall for the show flat. Numbers that do not add up on the back of an envelope rarely add up in the sanction file either.
What decides the FAR I am allowed in Bengaluru?
Mainly the width of the road your plot faces, under the BDA and BBMP rules in the Revised Master Plan. Broadly, plots on roads up to 30 feet get a lower FAR, in the region of 1.75 to 2.25, plots on 40 foot roads a little more, and plots on roads wider than 60 feet the highest FAR, in the range of 3.25 to 4.0. The logic is that wider roads can absorb the traffic and services that denser buildings generate. These bands are indicative and are governed by the master plan and zoning for the specific plot, so treat them as a guide and confirm the exact permissible FAR for the property with the sanctioning authority rather than assuming a number from a brochure.
| Road width abutting the plot | Approximate permissible FAR | What it means |
|---|---|---|
| Up to 30 feet | About 1.75 to 2.25 | Lower density, smaller buildings |
| 40 feet | About 2.25 to 2.5 | Medium density permitted |
| Above 60 feet | About 3.25 to 4.0 | Higher density, taller buildings |
| Premium FAR or TDR | Additional FAR on payment or transfer | Can raise the buildable area lawfully |
| Governing framework | BDA and BBMP, Revised Master Plan | Confirm the sanctioned FAR for the plot |
What are premium FAR and TDR?
They are lawful ways for a developer to build more than the base FAR. Premium FAR lets a developer buy additional floor area ratio from the authority by paying a premium, typically where the road width allows, and Transferable Development Rights, or TDR, let development potential from one plot, often one surrendered for a public purpose such as road widening, be used on another. Both are legitimate and are reflected in the sanctioned plan, so a building using premium FAR or TDR is not over built as long as the extra area is properly sanctioned. The distinction that matters to you is between extra area that is officially approved through these routes and extra floors simply constructed without sanction, which is a very different and riskier situation. The practical test is documentary: approved extra area appears in the sanctioned plan and the approval papers, while unauthorised area does not. So when a building looks denser than its road width would suggest, do not assume the worst, but do ask to see the premium FAR receipt or the TDR document that justifies it. A developer using these routes properly will have the paperwork ready, and a reluctance to produce it tells you something in itself. It is a small ask that separates a confident, compliant seller from one hoping you will not look too closely.
Why does FAR matter to me as a buyer?
Because a building that exceeds its sanctioned FAR carries real risk. Construction beyond the approved FAR is unauthorised to that extent, and unauthorised area can hold up the occupancy certificate, invite penalties or regularisation demands, and make the flat harder to finance and to resell. A bank scrutinises the sanctioned plan, and a buyer who follows you will do the same. This is why FAR sits alongside title as a core check, not an optional one. When you are comparing projects, a development that has used its FAR sensibly and holds a clean occupancy certificate is worth more to you than one squeezing extra saleable area out of a plot in ways the plan never approved. Read it together with the legal review we describe in our guide to legal opinion and title scrutiny.
How do I check a building's FAR compliance?
Compare the sanctioned plan against what is actually standing. Ask the developer or seller for the sanctioned building plan and the approval from the BBMP or BDA, and check that the number of floors and the built area match what was approved. If a building has more floors or more area than the sanction shows, that gap is the unauthorised portion and needs a clear explanation, whether through premium FAR, TDR or a regularisation. Cross check with the occupancy certificate, since a clean OC is strong evidence that the authority accepted the building as built. If you are evaluating a specific launch such as this Bengaluru project, ask for its approvals early, and once satisfied, plan your registration cost using our note on Karnataka stamp duty and registration charges.
What should I check before I book?
Run this list before you pay a booking amount.
- Ask for the sanctioned building plan and the BBMP or BDA approval for the project.
- Note the permissible FAR for the plot, which depends mainly on the abutting road width.
- Check that the built floors and area match the sanctioned plan, not just the brochure.
- Ask whether any extra area is backed by premium FAR or TDR, and get proof.
- Confirm the building holds a clean occupancy certificate for the built area.
- Treat unexplained extra floors or area as a serious risk to finance and resale.
- Have your lawyer review the approvals alongside the title documents before you commit.
Frequently asked questions
What is the difference between FSI and FAR? There is no real difference. FSI, or Floor Space Index, and FAR, or Floor Area Ratio, both describe the ratio of a building's total floor area to the plot area. FAR is usually written as a decimal, such as 2.0, while FSI is sometimes expressed as a percentage, such as 200 percent, but they measure the same thing.
How is FAR calculated? FAR is the total built floor area divided by the plot area, so the maximum buildable area equals the plot area multiplied by the permissible FAR. On a 2,000 square foot plot with a FAR of 1.5, up to 3,000 square feet can be built across all floors, before setbacks, height limits, coverage caps and parking rules further shape what is actually possible.
What decides FAR in Bengaluru? In Bengaluru, permissible FAR is set by the BDA and BBMP under the Revised Master Plan and depends mainly on the width of the road facing the plot. Narrow roads carry a lower FAR and wide arterial roads a higher one. Always confirm the exact permissible FAR for the specific plot with the sanctioning authority rather than assuming a number.
Why should a buyer care about FAR? Because a building constructed beyond its sanctioned FAR is unauthorised to that extent, which can hold up the occupancy certificate and make the flat harder to finance and resell. Checking that the built area matches the sanctioned plan, and that the building holds a clean occupancy certificate, protects you from buying an over built property.
Last updated 2026-09-14. PropNewz Team.
Contact Us
Stay updated with latest news and new projects!
Tell us what you want, We'll do the rest.
Share your budget and where you're looking. An advisor who has actually walked the sites will shortlist a handful of RERA-registered projects and tell you which to skip.