A Bengaluru buyer touring a nearly finished apartment block on a narrow road noticed the building seemed to have one more floor than the neighbouring projects on wider streets. His question to the sales team, why is this one taller, turned out to be the right one. The answer lay in a planning number few buyers ever ask about, the floor area ratio, which quietly decides how much a builder is allowed to construct on a plot. When a building carries more than its permitted share, that extra area can become a compliance problem you inherit. Here is what FSI and FAR mean, and why they matter to you.

The short answer. FSI, the floor space index, and FAR, the floor area ratio, are two names for the same planning rule, the ratio of the total built up floor area to the plot area. In India the term FAR is used, and in Bengaluru the permissible figure depends mainly on the width of the road your plot faces, along with the zone. Residential FAR generally ranges from about 1.5 to 2.75. The trade off for a buyer is compliance. A higher FAR means a builder can legitimately build more, but building beyond the sanctioned FAR is a deviation that can jeopardise the occupancy certificate, complicate loans, and even invite action, so you want to confirm a project stays within its limit.

What is FSI or FAR?

FSI and FAR both describe how much floor area may be built on a given plot, expressed as a ratio. Floor area ratio is the total built up area of all floors divided by the area of the plot, and floor space index is simply the same idea under a different name, more common outside India, as explained in this guide to floor area ratio. A FAR of 2.0 on a 1,000 square foot plot means up to 2,000 square feet of built floor area is permitted across the floors. The ratio does not by itself dictate the number of floors, since that also depends on height rules and coverage, but it caps the total floor area, which is what controls the overall bulk of a building.

How is FSI calculated?

You divide the total built up floor area by the plot area, and the result is the FSI or FAR. So a builder with a 10,000 square foot plot and a permitted FAR of 2.0 may construct up to 20,000 square feet of floor area in total. Increase the FAR to 2.5 and the same plot allows 25,000 square feet, which is why FAR is such a valuable number to a developer. For a buyer the calculation matters in reverse. If you know the plot area and the permitted FAR, you can sense whether the total built area being sold looks consistent with what is legally allowed, or whether the numbers seem stretched beyond the limit.

What FSI applies in Bengaluru?

In Bengaluru the permitted FAR depends primarily on the width of the road abutting the plot, with wider roads allowing more. Residential developments generally fall in a range from about 1.5 to 2.75, commercial projects can go higher in select zones, up to around 4.0, while industrial use sits near 1.0 and public or semi public buildings around 2.0. The rules are administered by the Bruhat Bengaluru Mahanagara Palike within corporation limits and by the Bangalore Development Authority for its layouts, under the master plan framework. Because the exact figure turns on road width, zone and the specific regulations in force, the permitted FAR for one plot can differ from a plot just streets away.

FAR also gives you a quiet read on density and livability. A higher permitted FAR lets a developer pack more built area, and therefore usually more flats, onto the same land, which can mean more residents sharing the lifts, parking, water and open space. That is not automatically bad, since well designed dense projects can still be pleasant, but it is worth noticing. Two projects on similar plots can feel very different to live in if one is built to a much higher FAR than the other, so reading the FAR alongside the number of units and the amenity provision tells you something the brochure photographs will not.

What is premium FAR?

Premium FAR is extra floor area a developer can buy above the base limit, allowed on wider roads under a state policy. Karnataka's premium FAR framework, gazetted in early 2025, permits developers to purchase additional FAR above the base figure on roads wider than 12 metres, with the extra allowance rising for wider roads. This is why two projects on different road widths can legitimately differ in bulk, and it is entirely lawful when the premium FAR is properly purchased and sanctioned. For a buyer the point is not to fear a taller building, but to confirm that any additional area was obtained through the proper premium FAR route and reflected in the sanctioned plan, rather than simply built without authorisation.

A related idea you may hear is transferable development rights, often shortened to TDR, which is another lawful way extra buildable area reaches a project. When a landowner gives up part of their land for a public purpose such as road widening, they can receive development rights that can be used elsewhere or sold, adding to the buildable area on the receiving plot. Like premium FAR, TDR is legitimate when it is properly documented and loaded into the sanctioned plan. The common thread is simple. Extra floor area is fine when it came through an approved mechanism and appears on the sanction, and a concern only when a building has more area than any approval accounts for. As a buyer you do not need to master the mechanisms, only to confirm that the built bulk is fully covered by sanctions.

Why does FSI matter to a buyer?

Because a building that exceeds its sanctioned FAR carries a real compliance risk that can land on you. When a developer constructs more floor area than the plan permits, that excess is a deviation, and deviations can hold up or invalidate the occupancy certificate, create difficulty with home loans on the affected units, and in serious cases attract regulatory action against the unauthorised portion. A building comfortably within its FAR, by contrast, is far more likely to secure a clean occupancy certificate and behave normally at resale. This is why FAR sits close to the occupancy certificate in importance, a link we cover in our guide to the occupancy certificate versus completion certificate.

How do I check a project's FSI?

You check it against the sanctioned building plan, which shows the approved FAR and built area. Ask the developer for the sanctioned plan and confirm the total constructed floor area matches what was approved for that plot and road width. Where extra area exists, confirm it came through a proper premium FAR sanction rather than an unapproved addition. A quick sense check is to compare the plot area and the FAR against the total saleable area being marketed, since a large mismatch is a prompt to dig deeper with a professional. The cost sheet and the sanctioned plan together tell the real story, which is why we also explain the builder cost sheet and its charges. If you are weighing a project like Sobha Oakshire in Devanahalli, ask to see the sanctioned plan, not just the brochure.

What should a Bengaluru buyer check?

Work through these seven steps so FAR is a comfort rather than a hidden risk.

1. Ask the developer for the sanctioned building plan showing the approved FAR.
2. Confirm the total built floor area matches the FAR permitted for that plot and road width.
3. Check whether any extra area came through a proper premium FAR sanction.
4. Be cautious if a building looks bulkier than neighbours on similar roads.
5. Link the FAR check to the occupancy certificate, since deviations can block it.
6. Confirm your lender is comfortable funding units in the building.
7. Use a professional to review the plan where the numbers look stretched.

FSI and FAR sound like jargon for architects, but they are really about whether a building is the size the law allows, and that question sits underneath your occupancy certificate, your loan and your resale. Learn the plot area and permitted FAR, check the sanctioned plan, and confirm any extra bulk was properly sanctioned. Do that and a number most buyers ignore becomes a simple, powerful test of whether the home you are buying stands on solid legal ground.

Frequently asked questions

What is the difference between FSI and FAR? There is no real difference. FSI, the floor space index, and FAR, the floor area ratio, are two names for the same planning rule, the ratio of total built up floor area to plot area. India generally uses the term FAR, while FSI is more common elsewhere. Both cap how much floor area may be built on a given plot.

What is the FSI for residential property in Bengaluru? Residential FAR in Bengaluru generally ranges from about 1.5 to 2.75, depending mainly on the width of the road abutting the plot and the zone. Commercial projects can go higher in select zones. Because the figure turns on road width and zone, the permitted FAR can differ between plots that are quite close to each other.

Why does FAR matter when I buy a flat? A building that exceeds its sanctioned FAR carries a compliance risk. Excess construction is a deviation that can delay or invalidate the occupancy certificate, complicate home loans on the affected units, and in serious cases attract action. A building within its FAR is far more likely to get a clean occupancy certificate at resale.

How do I check a building's FAR? Ask the developer for the sanctioned building plan, which shows the approved FAR and built area, and confirm the total constructed floor area matches it for that plot and road width. If extra area exists, check it came through a proper premium FAR sanction. Where the numbers look stretched, have a professional review the plan before you commit.

Last updated 2026-08-26. PropNewz Team.