Carpet Area vs Super Built-Up Area: The Number a Bengaluru Buyer Should Compare

A buyer comparing two Bengaluru apartments was quoted a similar price per square foot for both and assumed they were roughly equal value. Only when she asked for the carpet area did the picture change. One flat advertised on super built-up area was carrying a loading of nearly 40 percent, while the other, quoted on the same headline rate, was closer to 30 percent. The usable space she would actually live in differed by a room's worth, even though the price per square foot looked identical. The number that mattered was not on the brochure's front page. That single question, what is the carpet area, is the most useful one a buyer can ask, and it is remarkable how often it goes unasked in the excitement of a show flat. The finish, the view and the amenities all draw the eye, but the carpet area is what you will live inside for years, and it is the only measure that lets you compare one project honestly against another.

The short answer. Carpet area is the net usable floor space inside your flat, as defined by RERA, while super built-up area adds a share of common areas like lobbies, lifts and the clubhouse, and the gap between the two is the loading factor, often around 30 to 40 percent in Bengaluru. Since the Real Estate (Regulation and Development) Act, 2016, builders must sell and advertise on carpet area, which is the figure you should compare across projects. The trade-off to understand: super built-up area is not a fiction, since you do use the common areas, but it is not usable private space, so a price per square foot is only meaningful when you know which area it is based on.

What is carpet area under RERA?

Carpet area is the net usable floor area of your apartment, the space you could literally lay a carpet over. RERA defines it in Section 2(k) of the Real Estate (Regulation and Development) Act, 2016 as the net usable floor area, excluding the external walls, areas under service shafts, and exclusive balcony, verandah and open terrace areas, but including the area covered by the internal partition walls. In plain terms, it is the floor inside your flat, counting the internal walls but not the thick outer walls or the shaft that carries the plumbing. This is the honest measure of how much room you are actually buying to live in.

Because carpet area strips out the parts you cannot use as living space, it is the number that lets you compare flats fairly. Two apartments quoted at the same super built-up size can have noticeably different carpet areas depending on how the common areas are apportioned, so a buyer who compares on carpet area is comparing like with like, while one who compares on super built-up may be paying the same for less real space.

What is super built-up area, and what is the loading factor?

Super built-up area is the built-up area of your flat plus a proportionate share of the building's common areas, such as the lobby, staircases, lifts, corridors and shared amenities like a clubhouse or gym. It is the largest of the area figures and, before RERA, was the number most commonly used to quote prices, which is exactly why the same rupees per square foot could buy very different amounts of usable space. The built-up area itself sits between carpet and super built-up, adding the thickness of the walls and certain internal areas to the carpet figure.

The loading factor is the gap between super built-up and carpet area, expressed as a percentage, and it tells you how much of what you are being sold is common area rather than private space. It is calculated as the super built-up area minus the carpet area, divided by the carpet area. A loading of roughly 25 to 35 percent is common across India, and in Bengaluru it often runs a little higher, in the region of 30 to 40 percent. A higher loading is not automatically bad, since generous common areas and amenities have value, but it does mean a larger share of your money is buying shared space, so it is worth knowing the number rather than ignoring it.

Why does RERA make builders sell on carpet area?

RERA requires sales and advertising to be based on carpet area precisely to end the confusion that super built-up quoting created. Before the Act, a buyer could be quoted a flat's size on super built-up area, pay accordingly, and only later realise how much smaller the usable space was. By mandating carpet area as the basis, RERA gives every buyer a consistent, comparable and honest measure of the space they are purchasing, and it puts the same definition in front of every builder. The carpet area is disclosed on the project's RERA registration, which is one more reason to check that record, as we set out in our guide to verifying a project's RERA registration in Bengaluru.

For a buyer, the practical effect is that you should always ask for and compare the carpet area, and you should make sure it is the carpet area, not the super built-up area, that appears in your agreement. The agreement is where this number becomes binding, which connects directly to the care you take over that document, covered in our guide to the agreement to sell and the sale deed. If the carpet area is stated clearly in the agreement, you have something concrete to hold the builder to.

The three area terms compared

Here is how the three measures relate, and what each means for your decision.

The single most useful habit from this table is to convert every quote into a price per carpet square foot. Once you do that, two flats that looked similarly priced on super built-up area often separate clearly, and you can see which one is genuinely giving you more usable space for your money. It is also the number that protects your resale. A future buyer, or their bank's valuer, will look at the carpet area and the per-carpet-foot value, so a flat bought sensibly on that basis tends to hold its value more predictably than one where you overpaid for a high loading you never really used.

What happens if the carpet area falls short?

RERA gives you a remedy if the flat you receive has less carpet area than the agreement promised. Where the actual carpet area is less than what the agreement for sale stated, the builder is required to refund the excess amount you paid, along with interest, and this is generally to be done within a defined period after it is established. This protection is one of the concrete reasons the carpet area must be stated in your agreement: it is the figure the refund is measured against. Conversely, if the carpet area turns out larger, the position on any additional payment is also governed by the agreement, so read those clauses carefully.

Because this is a specific entitlement backed by the Act, it is worth confirming at possession that the carpet area you are handed matches the agreement, rather than assuming it does. Measure or have measured what you receive, compare it against the number in your agreement, and raise any shortfall promptly. The remedy exists, but you have to notice the gap and act on it, which is far easier when the carpet area was clearly recorded in writing from the start.

What is your area checklist before you buy?

Use this whenever a builder or broker quotes you a size or a per-square-foot price.

1. Ask for the RERA carpet area, not just the super built-up or saleable area.
2. Work out the loading factor from the super built-up and carpet figures.
3. Convert every quote into a price per carpet square foot to compare fairly.
4. Check the carpet area on the project's RERA registration record.
5. Make sure the carpet area is clearly stated in your agreement for sale.
6. Compare competing flats on carpet area and per-carpet-foot price, not headline size.
7. At possession, confirm the delivered carpet area matches the agreement.

Frequently asked questions

What is the difference between carpet area and super built-up area?

Carpet area is the net usable floor space inside your flat, as defined by RERA, excluding external walls, service shafts and exclusive balconies but including internal partition walls. Super built-up area adds a share of common areas like lobbies, lifts and amenities, so it is larger. The gap between them is the loading factor, so compare flats on carpet area.

Does RERA require builders to sell on carpet area?

Yes. Since the Real Estate (Regulation and Development) Act, 2016, builders must sell and advertise apartments on the basis of carpet area, using RERA's standard definition. This replaced the older practice of quoting on super built-up area. As a buyer, insist that quotes and your agreement state the RERA carpet area, the comparable measure across every project.

What is a normal loading factor in Bengaluru?

A loading factor of roughly 25 to 35 percent is common across India, and in Bengaluru it often runs a little higher, around 30 to 40 percent. The loading is the gap between super built-up and carpet area as a percentage of carpet area. A higher loading means more of your money buys common space.

What can I do if my flat has less carpet area than promised?

Under RERA, if the actual carpet area is less than the agreement for sale stated, the builder is required to refund the excess amount you paid along with interest, generally within a defined period. This is why the carpet area must be in your agreement. Confirm the delivered carpet area at possession and raise any shortfall promptly.

Last updated 2026-09-29. PropNewz Team.