Carpet Area, Built-up, and Super Built-up: What a Bengaluru Buyer Pays For

A Bengaluru buyer touring a sample flat in Whitefield in September 2026 was quoted a 1,200 square foot two bedroom apartment, then noticed the actual rooms felt smaller than a friend's 1,000 square foot flat elsewhere. The difference was not his imagination. The 1,200 figure was the super built-up area, padded with a share of corridors, lobbies, and walls, while the space he could actually furnish, the carpet area, was closer to 850 square feet. Learning the difference between these numbers is how a buyer stops paying for a figure and starts paying for a floor.

The short answer. Carpet area is the net usable floor space inside your flat, and under RERA it is the figure a builder must quote in advertisements, the agreement, and the registration. Built-up area adds the walls and balcony, and super built-up area adds a share of common areas, so the same flat has three different numbers that grow in that order. The trade-off is that a large super built-up figure can make a flat sound bigger than it lives, so a buyer should always compare flats on carpet area, which is the only one you can actually use.

What do carpet, built-up, and super built-up area mean?

These three terms describe the same flat at three widening boundaries, and knowing which one a price refers to changes what you are really buying. Carpet area is the usable floor space within your flat, the area you could in theory lay a carpet over. Built-up area adds the thickness of the walls and the balcony to the carpet area. Super built-up area adds a share of the building's common spaces, such as lobbies, corridors, staircases, and the lift area, spread across all the flats.

The numbers always grow in that order, carpet, then built-up, then super built-up. So a flat sold as 1,200 square feet super built-up may have a carpet area a few hundred square feet smaller. The rooms you live in are the carpet area, which is why a buyer who compares flats on carpet area is comparing like with like, and a buyer who compares on super built-up may be comparing different loading assumptions dressed up as size.

What is the RERA definition of carpet area?

Under Section 2(k) of the Real Estate (Regulation and Development) Act, 2016, carpet area is the net usable floor area of an apartment, excluding the area covered by the external walls, areas under services shafts, the exclusive balcony or verandah area, and the exclusive open terrace area, but including the area covered by the internal partition walls of the apartment. You can read the definition in the official statute on India Code. In plain terms, it is the space inside your flat, counting the internal walls but not the outer walls, shafts, balconies, or terraces.

This precise definition matters because it removed the old ambiguity where every builder measured area differently. With a single legal definition, the carpet area on one project's paperwork means the same thing as on another's, which is exactly what makes a fair comparison possible for a buyer. Before this definition existed, a buyer could be shown a large area figure by one builder and a smaller one by another for flats that were, in truth, almost the same size, simply because each measured differently. The standard definition took that confusion out of the buyer's hands and put a common ruler in them.

Does the builder have to quote carpet area?

Yes. Under Section 4 of the Act, a promoter must disclose the carpet area in the advertisement, the agreement for sale, and the registration details of a registered project. This is one of RERA's most practical protections for a buyer, because it forces the number you can actually use into the documents, rather than leaving you with only the inflated super built-up figure that marketing prefers. A builder may still mention super built-up area, but the carpet area must be there, and it is the figure your agreement should turn on.

The table below sets out the three measures and a couple of related terms, so you can see what each one includes and how to read it.

What is the loading factor and why does it matter?

The loading factor is the gap between the super built-up area and the carpet area, expressed as a percentage added on top of the carpet. A loading of twenty to thirty percent is common, so a flat with 850 square feet of carpet and thirty percent loading is sold as about 1,105 square feet super built-up. The higher the loading, the more of the headline number is common area rather than your own space, and two flats with the same super built-up figure can have quite different carpet areas if their loading differs.

For a buyer, the loading factor is a quick sanity check. Ask for both the carpet area and the super built-up area, work out the gap, and compare it across the projects you are considering. A much higher loading than the others is not automatically wrong, because it can reflect more generous common areas, but it does mean you are getting less private space per rupee of the headline price, and that is worth knowing before you decide. Some buyers happily pay for a grand lobby and wide corridors, and others would rather have the space inside their own flat, so there is no single right answer, only a choice you should make with the real numbers in front of you rather than by accident.

How do I check the real usable area of a flat?

Start from the carpet area in the agreement, not the super built-up figure in the brochure. Ask the builder to state the carpet area in writing, confirm it matches the agreement and the RERA disclosure, and use that number to compare flats and to judge whether the space suits your needs. If only a super built-up figure is offered, ask for the carpet area explicitly, because you are entitled to it and it is the figure the law puts at the centre of the deal. Where you can, visit the actual flat or a same layout sample and see the space rather than trusting a number alone.

This is buyer guidance, not investment advice. The aim is simply to make sure the space you are paying for is the space you can use, and that you are comparing projects on the same honest measure rather than on marketing figures that may not line up. A flat that shows well in a brochure but has a high loading can end up feeling cramped once furnished, while a modestly quoted flat with low loading can live larger than its headline number suggests. The carpet area, seen in person, is what tells you which is which.

How does area affect my other decisions?

Carpet area feeds into more than how the flat feels, because it also drives certain tax and cost questions. The affordable housing definition for the lower GST rate, for instance, is measured on carpet area, not the super built-up figure, as covered in our guide to GST on under construction flats. Area also connects to how much can be built on a plot, which is governed by rules explained in our note on FSI and FAR. A buyer weighing a project such as TVS Emerald in Whitefield would ask for the carpet area first and let the other numbers follow from it.

A seven step area check for buyers

Use this order before you compare prices or sign the agreement for the flat.

1. Ask for the carpet area of the specific flat in writing.
2. Ask for the super built-up area as well, for the same flat.
3. Work out the loading as the gap between the two figures.
4. Compare flats on carpet area, not on super built-up.
5. Confirm the carpet area matches the agreement and RERA disclosure.
6. Compare the loading factor across the projects you are considering.
7. Visit the flat or a same layout sample to see the real space.

Frequently asked questions

What is the difference between carpet area and super built-up area? Carpet area is the usable floor space inside your flat, while super built-up area adds the walls, the balcony, and a share of common areas such as lobbies and corridors. The super built-up figure is always larger, so a flat quoted as 1,100 square feet super built-up may have only around 850 square feet of carpet you can use.

Does RERA require the builder to quote carpet area? Yes. Under Section 4 of the Act, a promoter must disclose the carpet area in the advertisement, the agreement for sale, and the registration details of a registered project. The builder may also mention super built-up area, but the carpet area must be stated, and it is the figure your agreement should turn on.

What is a good loading factor? A loading factor of around twenty to thirty percent is commonly seen, meaning the super built-up area is that much larger than carpet. There is no single correct number, but a much higher loading than comparable projects means less of your headline area is private space. Compare loading across the flats you are considering rather than judging one figure alone.

Which area should I use to compare two flats? Always the carpet area. Because RERA defines carpet area the same way for every project, it lets you compare flats like with like, whereas super built-up figures can hide different loading assumptions. Ask each builder for the carpet area, confirm it against the agreement, and base your comparison and your sense of the space on that number.

Last updated 2026-09-19. PropNewz Team.