Carpet Area Is the Law Now. So Why Do You Still Hear “Built-Up” All Over Navi Mumbai?
Spend a weekend looking at apartments anywhere in Navi Mumbai or the wider MMR and you will notice something. People are still talking in built-up and super built-up area. A broker quotes you a size, a listing implies one, a relative who bought five years ago tells you what their flat “is.” The number that gets thrown around is almost always the bigger one.
Which is strange, because that stopped being how homes are legally sold years ago.
We quote carpet area, plainly, and we think you should insist on it from anyone you talk to. Here is why the older language refuses to die, what it quietly costs you, and how to see straight through it.
What the law actually says
When RERA came into force, it did something specific and important. It made carpet area the legal basis for selling a home, and it declared the old practice of selling on vague super built-up area illegal. Carpet area got a clear, fixed definition: the net usable floor space inside your walls. Every agreement for sale, every sale deed, and every piece of marketing is required to state the carpet area.
So in principle, this whole confusion should be over. The number in your agreement is carpet area, full stop. The law even protects you if the delivered carpet area falls short of what was promised by more than a small margin, with a refund and interest.
And yet the built-up language survives. That is not an accident, and it is worth understanding why.
Why “built-up” refuses to die
The honest answer is that the bigger number is useful to whoever is selling, in three quiet ways.
It makes the home sound larger. “A 900 square foot flat” lands better than “a 650 square foot flat,” even when they are the exact same apartment described two different ways. The larger figure feels like more house for the money.
It makes the rate look cheaper. This is the one that actually catches people. A per square foot price quoted on a big super built-up number looks lower than the same home priced on its smaller carpet number, even though you pay precisely the same total. The low headline rate is an illusion created by dividing the price across inflated area.
And it is simply habit. For decades the whole market spoke in super built-up area, so brokers, buyers and old listings still default to it out of muscle memory, not always out of any intent to mislead. But muscle memory or not, the effect on you is the same, which brings us to the part that matters.
The loading factor, in plain terms
The gap between the carpet area you can actually use and the super built-up area you are charged for has a name. It is called the loading factor, and it covers your share of lobbies, lifts, corridors, staircases, clubhouses and the rest of the common space.
A little loading is normal and fair, because those shared spaces are real and someone has to pay for them. The problem is how large it has quietly become. In Mumbai, loading has crept up to around forty percent on average, which means in many towers barely half of the super built-up area you pay for is space you can stand in. The rest is your slice of the amenities.
Here is the example that makes the whole thing click. Imagine two apartments.
The first is quoted at six thousand rupees per square foot, sounds like a bargain, but carries forty-five percent loading. The second is quoted at seven thousand rupees per square foot, sounds more expensive, but carries only twenty-five percent loading. Most buyers assume the first is clearly cheaper. Work it out on the space you actually use and the first costs about eight thousand seven hundred rupees per carpet square foot, while the second costs about eight thousand seven hundred and fifty. They are, for all practical purposes, the same price. The “cheaper” flat was never cheaper. It just had more of its price hidden inside loading.
That is the entire game in one example. A low per square foot rate tells you almost nothing on its own. A low rate on a high loading factor is just a high rate wearing a disguise.
Why this matters even more at the affordable end
If you are buying a premium tower, loading eats into a large budget and you can absorb it, irritating as it is. If you are buying an affordable home, every usable square foot matters more, because you have fewer of them and you paid hard for each one. A heavily loaded affordable flat can leave you with surprisingly little real living space while the brochure number looked perfectly generous.
This is one of the quieter advantages of buying in the developing corridors rather than the dense city. Projects out here generally do not carry the forty and fifty percent loading of premium city towers, so more of what you pay for tends to be space you actually live in. But you should never take that on trust from anyone, including us. You should check it.
How to see straight through it
The good news is that the tools to protect yourself are simple, and they work on any developer.
Ask for the RERA carpet area in writing, not the super built-up area and not some informal “usable” figure that quietly folds in the balcony. Then verify it yourself on the MahaRERA portal, where the registered carpet area for the project is filed publicly. Calculate the loading factor, which is just the super built-up area minus the carpet area, divided by the carpet area. And when you compare two homes, always compare them on price per carpet square foot, never on the headline rate. Remember too that your bank values the home on carpet area, so budgeting your loan off a super built-up number can leave your maths wrong from the start.
A developer who answers all of that easily and in writing is telling you something good about how they operate. One who gets vague when you ask for carpet area in the agreement is telling you something too.
Where we stand
We quote carpet area because that is the space you will actually live in, and because the law settled this question already even if the market’s habits have not caught up. We would rather you knew exactly what you were paying for, did the loading maths on us as hard as on anyone else, and chose with clear eyes.
Being small enough that you can ask these questions directly to the people who built the project, and get a straight number back rather than a sales deflection, is the part of how we work we are most willing to be measured on. The carpet area is the home. Everything else is just how the price was dressed up.