Check Your Building's FSI Potential Before Inviting Bids

Knowing roughly what your plot can build is the difference between negotiating from facts and negotiating from hope.

FSI, or Floor Space Index, is the total permitted floor area divided by your plot area under DCPR 2034. Your plot size, road width and the applicable 33-series scheme decide it. Work out a rough figure before inviting bids, so no developer can understate your potential.

What exactly is FSI?

FSI, or Floor Space Index, is the total floor area a building may have, divided by the area of the plot it stands on. That is how DCPR 2034 defines it for Greater Mumbai. More permitted floor area means more saleable flats — and it is that extra saleable area which pays for your bigger flats, your corpus and your rent during construction.

What decides how much your plot can take?

Everything here is specific to your address. The size and shape of the plot, the width of the access road, the zone, whether your building is cessed, and which incentive scheme applies — 33(7) and 33(7A) for cessed buildings, 33(7B) read with 20(B), 33(9) for cluster, 33(14) for slum. Fungible Compensatory Area under Regulation 31(3) and TDR under Regulation 34 can add more still. Anyone who quotes you one universal FSI number for all of Mumbai is guessing. Our DCPR 2034 guide explains these terms slowly.

Why do this before inviting bids?

A society that does not know its own potential negotiates blind. If the committee has no rough idea of the envelope, a developer's offer of, say, 30 per cent extra area sounds generous — even when the plot could comfortably support more. A half-hour with the numbers changes the conversation: you can ask why an offer falls short of what the plot appears able to deliver, and judge every bid on the same basis.

Start with the FSI and feasibility calculator, then see what that could mean for your own flat in the additional area calculator. Treat both as indicative. The binding figure comes only from your architect's plans and the approvals your plot actually receives — but an indicative figure is still far better than none when the bids arrive.

Work it out for your own society

It gives your society an indicative FSI and buildable area for your own plot, road width and likely DCPR scheme.

Open the FSI & Feasibility Calculator

Common questions

Is there one standard FSI for all Mumbai societies?

No. Under DCPR 2034, FSI is total floor area divided by plot area, and the permitted figure depends on your plot size, access road width, zone, cessed status and the applicable 33-series scheme. Fungible Compensatory Area and TDR can change it further. Any single number offered as universal for Mumbai should be treated with caution.

Can we simply rely on the developer's own FSI working?

You can read it, but verify it independently. Developers prepare their own feasibility, and their commercial interest lies in a conservative reading of what the plot can deliver. Run your own indicative working first, then ask each bidder to show the assumptions behind theirs, including road width, scheme, fungible area and TDR, and compare them side by side.

Do we need an architect before inviting bids?

Not necessarily at the very first stage. An indicative calculation is enough to frame the tender and read offers sensibly. Before you sign anything, though, appoint your own architect and legal adviser, since only sanctioned plans settle the actual buildable area. The Section 79A process and the Development Agreement should follow that professional advice.