Carpet Area vs Built-Up vs Super Built-Up Area
Ask two sales offices for the size of a flat and you can get two numbers thirty per cent apart for the same apartment. Neither of them is lying, exactly. They are quoting different measurements, and only one of those measurements is the space you can actually stand in. Getting this right is the cheapest way to avoid overpaying in a market where rates are quoted per square foot.
What does carpet area legally mean in Maharashtra?
Under RERA, carpet area is the net usable floor area within the walls of your apartment — excluding the external walls, the shaft areas, the exclusive balcony or verandah, and the exclusive open terrace, but including the area covered by internal partition walls.
That definition matters because it is the one the law puts in your agreement. A registered agreement for a RERA-registered project has to state the carpet area, which makes it the only figure with a fixed, enforceable meaning behind it.
Everything else you will be quoted — built-up, super built-up, saleable area — is a commercial construct. Useful for a developer's pricing model, not defined for your protection.
How do built-up and super built-up differ from carpet?
Built-up area adds the thickness of the walls and typically the balcony to your carpet area. Super built-up area then adds your share of the building's common spaces — lobbies, staircases, lifts, and often amenity areas — on top of that.
The step from carpet to super built-up is called loading, and it is where the size of your flat quietly inflates. A project with generous common areas and an elaborate amenity deck will carry higher loading than a plain one, and you pay for that in the per-square-foot maths whether you use the clubhouse or not.
There is no legally fixed loading percentage. Two projects on the same road can load very differently, which is precisely why comparing them on quoted rate per square foot without normalising to carpet is meaningless.
How do you compare two flats fairly?
Divide the total all-in cost by the carpet area, for both flats, and compare those two numbers. That is the whole method, and it will reorder your shortlist more often than you expect.
- Get the carpet area in writing for every option you are seriously considering — brochure figures are not enough.
- Use the total acquisition cost, not the base price: include statutory charges, parking, deposits and floor premium.
- Ignore the quoted rate per square foot entirely until you know which area it is quoted against.
- Ask what the balcony and terrace are counted as, since they sit outside the RERA carpet definition but are often marketed as living space.
- Cross-check the figure in the draft agreement against the figure in the sales presentation before you sign anything.
Why does this matter so much in Navi Mumbai specifically?
Because Navi Mumbai's supply spans compact entry stock and large premium formats within the same nodes, and loading tends to be heaviest at exactly the amenity-led end of the market where buyers are already stretching their budget.
It also matters for resale. Buyers in a few years' time will compare on carpet, because that is what agreements record. A flat that was sold to you on a generous super built-up number and resells on a modest carpet number is a bad surprise waiting to happen.
Every project page on this site shows a tracked carpet range for exactly this reason, so you can line up options honestly — whether you are looking at Kharghar inventory, the Taloja value belt or premium Nerul stock.
What should be in your agreement about area?
The carpet area of your apartment, stated in the registered agreement, along with the treatment of any balcony, terrace or exclusive open area attached to it. If the agreement is silent or vague on this, that is the moment to stop.
Check that the number in the agreement matches the number you were sold. It is a small check that takes two minutes and it is skipped far more often than it should be, usually because registration day feels like a formality by the time you reach it.
If anything material was promised verbally and does not appear in the paperwork, correct it before signing rather than afterwards. Our step-by-step buying guide covers where in the process this check belongs, and the RERA guide covers what protections sit behind it.
