MahaRERA Carpet Area vs Marketed Size: How to Read a Mumbai Price Sheet

Two buyers walk out of the same sales lounge in Andheri West. One says she is buying a 1,510 sq ft three-bedroom. The other says he is buying a 1,363 sq ft three-bedroom. They are describing the same apartment.

Neither of them has been lied to. They have been given two different measurements, both legitimate, in an order that makes the larger one memorable. This article is about the difference, because at Mumbai rates a tenth of a flat is a very large amount of money — and because the gap is easy to check once you know where to look.

What the law says

Carpet area is not a marketing term. It is defined in statute.

Section 2(k) of the Real Estate (Regulation and Development) Act, 2016 defines carpet area as the net usable floor area of an apartment, excluding the area covered by external walls, areas under services shafts, exclusive balcony or verandah area, and exclusive open terrace area — but including the area covered by the internal partition walls of the apartment.

Three consequences follow, and they are the whole of what you need.

1. Your balcony is not in it. Nor is your open terrace. Both are excluded by name.
2. Your internal walls are in it. Carpet area is not the area of the carpet you could lay. It is measured to the inside face of your external walls, with your own partition walls counted.
3. There is no RERA definition of "super built-up", "saleable" or "marketed" area. Those are conventions. Different developers compute them differently, and nothing requires two projects to compute them the same way.

Since the Act came into force, residential sale in India is transacted on carpet area, and carpet area is the figure that must appear in your agreement for sale. Everything else on the price sheet is context.

What a marketed size adds

In practice, the number printed large in a Mumbai brochure is the carpet area plus the exclusive areas that the law excludes from it — most commonly the balcony, and sometimes a deck, a terrace or a service area attached to that specific apartment.

The good brochures show you this arithmetic. A properly drawn unit plan carries three lines: RERA carpet area, balcony and other exclusive areas, and total area. Add the first two and you get the third. If a brochure prints only the third, that is the question to ask.

Worked example: The Westpark

DLF The Westpark publishes its Phase 1 area tables in exactly the three-line form above, which makes it a clean example to work through. Here are the Phase 1 figures, in square feet, straight from those tables:

Across Phase 1, carpet runs between roughly 87% and 93% of the printed total. That is a narrow, honest band, and it tells you the convention this developer uses: total area equals RERA carpet plus the balcony and other exclusive areas, nothing more.

Now apply that to Phase 2, where the marketed figures are the ones in circulation:

• Tower 6 · 3 BHK — marketed 1,510 sq ft, RERA carpet about 1,363 sq ft. The gap is about 147 sq ft. Compare that to the Tower 5 three-bedroom above: 1,363.27 carpet plus 147.54 balcony equals 1,510.81. It is the same layout and the same arithmetic. The marketed figure is the total, rounded.
• Tower 7 · 3 BHK — marketed 1,365 sq ft, RERA carpet about 1,261 sq ft. A gap of about 104 sq ft, carpet at about 92% of marketed — right in the Phase 1 band.
• Tower 6 · 4 BHK — marketed 2,600 sq ft, RERA carpet about 2,124 sq ft. A gap of about 476 sq ft, or roughly 18% of the marketed figure. That is wider than anything in the Phase 1 table, and it is the one number here that deserves a direct question: ask, in writing, exactly what the 476 sq ft consists of, line by line.

That last point is the method generalised. You are not looking for a developer to be wrong. You are looking for the components of a number to be stated.

Two traps in the numbers

The identical-headline trap. Tower 4 in Phase 1 contains a four-bedroom whose carpet area is 1,510.37 sq ft. Tower 6 in Phase 2 contains a three-bedroom whose marketed size is 1,510 sq ft, against about 1,363 sq ft of carpet. Same headline number, different measurement, roughly 147 sq ft of real difference — inside the same project. A number alone tells you nothing. A number with its basis attached tells you everything.

The bedroom-count trap. Tower 3's four-bedroom carries 1,277.50 sq ft of carpet. Tower 5's three-bedroom carries 1,363.27 sq ft. The three-bedroom is the larger home. Bedroom counts describe partitioning, not space — and in a market where a fourth bedroom can move an asking price, that distinction is worth real money.

What it does to a rate per sq ft

This is where the gap stops being academic.

Take any price for the Tower 6 three-bedroom. Expressed per marketed square foot, you divide by 1,510. Expressed per carpet square foot, you divide by 1,363. The carpet rate is about 11% higher than the marketed rate — for exactly the same money and exactly the same home.

On the Tower 6 four-bedroom, dividing by 2,124 instead of 2,600 produces a rate about 22% higher. Same money, same home, a number that looks very different on a comparison sheet.

So when you line up three projects in Andheri West and one looks cheaper per square foot, your first question is not "why is it cheaper". It is "cheaper per which square foot". A quote on marketed area will always look better than a quote on carpet, and portals rarely say which they are using. When Business Standard reported a Westpark penthouse registration in November 2025, it gave the rate as ₹76,500 per sq ft and specified that this was on a RERA carpet basis. That specification is the useful part of the sentence. Most listings omit it.

Verifying it yourself

This takes about fifteen minutes and costs nothing.

1. Get the MahaRERA registration number for the phase you are buying — not the project in general, the phase. The Westpark's Phase 1 is PR1181012500079, valid to 30/06/2032; Phase 2 is registered as Phase-1B under PR1181012602591, valid to 30/06/2034.
2. Search that number on maharera.maharashtra.gov.in. The project page carries the registered unit mix, the carpet area declared for each apartment type, and the uploaded approvals.
3. Compare the portal's carpet figure to the brochure's area table and to the stamped unit plan you were shown. The three should agree. If they do not, that is your conversation.
4. Check the validity date, and understand what it is not. The 30/06/2034 on Phase 2 is the outer limit of the registration. It is not a possession commitment. The date that binds a developer is the possession date written into your agreement.

What belongs in the agreement

Before you pay anything beyond a token, your draft agreement for sale should state, in figures you can check: the RERA carpet area of your apartment; the balcony and other exclusive areas, itemised separately; the apartment number, floor and tower; the parking allotted; the possession date; and the payment schedule with each milestone named.

If a number in the brochure does not appear in the agreement, it is marketing. If a number in the agreement does not match the MahaRERA portal, ask why before you sign — not after.