A couple booking a two bedroom flat in Whitefield, Bengaluru, in early 2026 were quoted a size of 1,250 square feet and a price per square foot that felt reasonable. Only when they read the agreement did they notice a smaller number tucked into the schedule: the carpet area, closer to 900 square feet. Nothing was wrong, and nothing was hidden. They were simply meeting two different ways of measuring the same home, and understanding the gap between them is one of the most useful things a buyer can do before signing.

The short answer. Carpet area is the net usable floor area inside your flat as defined by the Real Estate (Regulation and Development) Act, 2016, and since RERA came into force apartments in registered projects are sold on a carpet area basis. Super built up area is a larger figure that adds a share of common spaces, and it is often significantly bigger than carpet area. The trade-off to accept: carpet area tells you the space you actually get to use, but the headline price and per square foot rate may still be discussed in other terms, so you convert everything back to carpet area to compare fairly.

What is carpet area under RERA?

Carpet area, under Section 2(k) of the Real Estate (Regulation and Development) Act, 2016, is the net usable floor area of an apartment. It excludes the area covered by the external walls, areas under services shafts, any exclusive balcony or verandah area and any exclusive open terrace area, but it includes the area covered by the internal partition walls of the apartment. In plain terms, it is close to the space you could actually lay a carpet across, which is why the name fits.

This definition matters because it is standardised and legally grounded, applying across registered projects rather than varying builder by builder. Before this, size could be described in ways that flattered the flat, and two homes described with the same number could offer very different usable space. Carpet area gives a buyer a consistent yardstick, so the figure in one agreement means the same thing as the figure in another.

What is super built up area and how does it differ?

Super built up area is a larger measure that adds a proportionate share of common spaces to your usable space. On top of the carpet area, it loads in a portion of areas such as lobbies, staircases, lift shafts and other shared parts of the building. Because of these additions, the super built up figure is often significantly larger than the carpet area, sometimes by a quarter or more, which is why the same flat can be described with two very different numbers.

Neither figure is dishonest by itself, but they answer different questions. Super built up area reflects a share of the whole building attributed to your flat, while carpet area reflects the space inside your own four walls. The risk for a buyer is comparing a carpet area in one project against a super built up area in another, because that is not a like for like comparison. Knowing which number you are looking at is the first defence against a misleading impression of size.

Why did RERA change how flats are sold?

RERA changed the basis of sale to protect buyers from inflated size claims. Before the Real Estate (Regulation and Development) Act, 2016, builders often quoted super built up area, which made a flat appear larger and made it hard to know how much usable space you were paying for. By defining carpet area and requiring apartments in registered projects to be sold on that basis, the law gave buyers a consistent, enforceable measure of what they actually receive.

For a buyer this is a quiet but powerful shift. It means the size on which your flat is sold is the usable one, not a padded figure, and that projects can be compared on the same footing. It does not stop a seller from mentioning other numbers in conversation, but the agreement for a registered project should rest on carpet area. That gives you a firm reference to hold the discussion to, and it means the number you sign against is the usable one rather than a padded figure.

What does this mean for the price you pay?

It means you should convert every quote back to carpet area before comparing or deciding. A price per square foot looks very different depending on whether the foot is a carpet foot or a super built up foot, so the same rupee figure can flatter or fairly describe a flat. The single most useful habit is to ask for the carpet area in writing and work out the effective cost against that number.

How do I check the carpet area of a flat?

Start with the written documents, because a verbal size is not something you can rely on. Ask the builder for the carpet area in writing and confirm it appears clearly in the agreement and the project details. For a registered project you can also cross check the declared details against the state RERA record, since the project files declarations with the authority. Where the number in conversation and the number in the paperwork differ, the paperwork is what governs your purchase.

If you are comparing several flats, build a simple like for like table of carpet areas and effective prices, and ignore the marketing sizes until you have done so. This turns a confusing set of quotes into a fair comparison. A seller confident in the value of a flat should have no difficulty giving you the carpet area plainly, and reluctance to do so is itself worth noting.

What should a Bengaluru buyer watch for?

Watch for quotes that mix measures and for a gap between the marketing size and the agreement size. A brochure that leads with a large number while the agreement schedule carries a much smaller carpet area is not necessarily doing anything wrong, but you should understand the difference before you sign. Balconies, terraces and shared areas are treated in specific ways under the definition, so do not assume every square foot you see is usable interior space.

Be especially careful when comparing projects from different builders, since one may lead with carpet area and another with super built up. Reduce them both to carpet area and the comparison becomes honest. If anything about the size or its basis is unclear, ask for it in writing and, where needed, have your lawyer read the schedule before you commit any money.

How does carpet area fit into the wider decision?

Carpet area is the space side of the decision, and it works best beside the ownership and approval checks. Knowing your usable area tells you what you get, but not what share of the land you own or whether the project is approved, so it belongs alongside those questions rather than in place of them. A complete view for a Bengaluru buyer reads the usable area, the undivided share and the approvals together.

Pair this with our guide on the undivided share and the sale and construction agreement, and our explainer on spotting one sided clauses in a builder buyer agreement. If you are weighing a specific project, you can also review a listing such as this Bengaluru apartment project to see how details are presented. Together these cover space, ownership and fairness before you sign.

Your seven step carpet area checklist

1. Ask the builder for the carpet area of the flat in writing, not just verbally.
2. Confirm the carpet area appears clearly in the agreement schedule.
3. Note whether any figure quoted to you is carpet or super built up area.
4. Convert every per square foot rate back to a carpet area basis before comparing.
5. Cross check the declared project details against the state RERA record.
6. Compare flats only carpet against carpet, never across different bases.
7. If the numbers or their basis are unclear, get written clarification before paying.

Frequently asked questions

What is carpet area under RERA?

Carpet area, under Section 2(k) of the Real Estate Act, 2016, is the net usable floor area of an apartment. It excludes external walls, service shafts, exclusive balcony or verandah area and exclusive open terrace area, but includes the internal partition walls. It is close to the usable space inside your flat, and registered projects are sold on this basis.

How is super built up area different from carpet area?

Super built up area adds a proportionate share of common spaces, such as lobbies, staircases and lift shafts, on top of the carpet area. It is often significantly larger than carpet area, sometimes by a quarter or more. Carpet area is the usable space inside your flat, while super built up reflects a share of the whole building.

Are flats sold on carpet area or super built up area?

Since the Real Estate Act, 2016 came into force, apartments in registered projects are sold on a carpet area basis. A seller may still mention super built up figures in conversation, but the agreement for a registered project should rest on carpet area. Always confirm the carpet area in writing and read the agreement schedule closely before you sign.

Why does the difference matter when comparing flats?

Because a price per square foot means different things on carpet area versus super built up area. Comparing carpet area in one project against super built up in another is not like for like and can mislead you about value. Reduce every quote to a carpet area basis, then compare, so size and price are judged on the same measure.

Last updated 2026-07-16. PropNewz Team.