Additional free area calculator for redevelopment offers
Estimate the extra carpet area members can reasonably expect — so you can tell a generous offer from a low one.
The additional area calculator estimates the extra carpet area housing society members can realistically expect in a Mumbai redevelopment offer, based on plot area and total existing carpet. It shows the FSI already used on the plot and a typical free-area range, so committees can judge whether a developer's offer is generous or low before negotiations begin.
Estimate your extra area
A quick, realistic range based on your plot — it updates as you type. Nothing you enter leaves your device.
Is your building a cess (cessed) building?
This is a typical, realistic range — not a guarantee. The exact free area depends on your plot's FSI potential, the scheme used, and what your society negotiates. Use the FSI & feasibility calculator for a full plot-level estimate, and have any offer checked by your PMC and lawyer before you decide.
What does this tool do?
- Estimate a reasonable range of extra carpet area for your plot and locality
- Connect FSI potential to what actually reaches members as free area
- Show how corpus, rent and free area trade off against each other
- Help your committee set realistic expectations before negotiations begin
Why is extra area the number everyone argues about?
In most societies, the first question members ask about any offer is simple: how much bigger will my flat be? Because it is the number everyone feels directly, developers often lead with it — and it becomes the yardstick for every competing offer. The trouble is that extra area does not come from a rulebook; it comes from what your plot can actually generate and sell. If your society anchors its expectations to what a neighbouring society got, or to a developer's opening pitch, you may either reject a fair offer or accept a weak one. Knowing a realistic range for your own plot keeps the discussion grounded and the negotiation honest.
Common questions
How is the extra area in a redevelopment offer decided?
There is no fixed government percentage of extra area that every society gets. A developer builds more than what stands today by using the additional FSI available on your plot, and sells part of that new area to fund the project. Whatever the plot's economics can support — after construction costs, rent, corpus and the developer's own margin — is what reaches members as free area. That is why offers differ so much between plots and localities.
Is a bigger free area always the best offer?
No. Extra carpet area is only one part of the package. A sensible comparison looks at the whole offer: corpus fund, rent during construction, amenities, construction quality, project timeline, and the developer's track record and guarantees. An offer with slightly less area but stronger financial guarantees, a realistic timeline and a dependable developer can leave your members far better off than a headline-grabbing area figure that the project cannot actually deliver.
Related tools & guides
- FSI calculator — the source of every offer's economics
- Offer comparison tool — compare complete offers side by side
- Free offer review — have your offer checked in 5–10 days
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