A Bengaluru buyer compared two flats quoted at the same rate per square foot and assumed they were priced the same. One was sold on a super built up area of twelve hundred square feet, the other on the same headline size, yet when he asked for the carpet area, the usable space he would actually live in, the first came to around seven hundred and fifty square feet and the second closer to eight hundred and forty. Same price per foot, same headline size, and nearly a hundred square feet of real living space between them. The rate had told him almost nothing, because it was quoted on an area he would never set foot in.

The short answer. Carpet area is the usable space inside your flat; super built up area adds a share of walls, lobbies, staircases and other common spaces, and it is usually the bigger number builders quote. The gap between the two is the loading factor, commonly around thirty to forty percent in Bengaluru, which means a flat sold as a certain super built up size can have a carpet area only two thirds of that. RERA requires sale on carpet area, so the meaningful comparison between flats is the price per carpet square foot, not the marketing rate on super built up. The trade off is nothing but attention: ask for the carpet area and the loading, and you can compare flats on what you actually get to live in.

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

The three areas describe progressively larger measures of the same flat, and only the smallest is space you can actually use. The table below sets out what each one means for a buyer.

Carpet area is what you live in, built up area adds the thickness of your own walls and balcony, and super built up area then loads on a proportionate share of the building's common spaces such as lobbies, corridors and staircases. Each step up makes the flat sound larger while adding nothing you can furnish, which is exactly why the term used in a quote matters as much as the number attached to it.

What is the loading factor, and how big is it in Bengaluru?

The loading factor is the extra area added on top of carpet area to arrive at super built up area, expressed as a percentage of the carpet. If a flat has a carpet area of a thousand square feet and is sold as a super built up area of fourteen hundred, the loading is forty percent. In Bengaluru the loading commonly runs around thirty to forty percent, and in some projects the carpet area works out to little more than half the super built up figure, so the difference is not trivial. A higher loading is not automatically bad, since generous lobbies and amenities take space, but it does mean you are paying for less usable area per rupee than the headline rate suggests. The practical use of the number is comparison: two flats can look identical on super built up size and rate, yet differ materially in carpet area once their loadings are known. There is no single legal cap on loading, and different builders calculate the common area share differently, so two projects quoting the same super built up size can genuinely hand you different amounts of usable space, which is why the loading is a question to ask rather than a figure to assume.

Which number should I compare when pricing a flat?

Compare the price per carpet square foot, because that is the rate on the space you will actually use. A builder quoting a rate on super built up area is spreading your money across common spaces as well as your flat, so the same headline rate can hide very different real costs depending on the loading. To find the meaningful figure, take the total price and divide it by the carpet area, not the super built up area, and do the same for every flat you are weighing so you are comparing like with like. This single adjustment often reorders a shortlist, because a flat with a lower headline rate but a leaner loading can be cheaper per usable foot than one that looks better on the brochure. Anchor every comparison to carpet area, and the marketing rate loses its power to mislead. The same discipline helps when a builder offers a discount on the super built up rate, because a cut on an inflated base can still leave you paying more per usable foot than a rival quoting honestly on carpet area.

What does RERA require the builder to sell on?

RERA requires residential flats to be sold on carpet area, with the carpet area clearly disclosed, precisely so buyers are not sold on an inflated super built up figure alone. The law defines carpet area and obliges the builder to state it, and the agreement for sale is expected to record it, which gives you a certified number to hold the builder to rather than a loose marketing size. Some builders still show super built up area in brochures alongside the required carpet figure, which is not itself wrong, but the number that governs the sale is the carpet area. For a buyer, this means you are entitled to the carpet area in writing, and you should treat any reluctance to provide it plainly as a reason to press harder, not to let it go. The disclosure exists for your protection; use it.

What if the carpet area is smaller than promised?

If the actual carpet area turns out to be less than what the agreement for sale recorded, the framework provides for the builder to refund the excess you paid, with interest. Because the sale is on carpet area, a shortfall in that area is a shortfall in what you bought and paid for, and the buyer is entitled to be put back for the difference rather than simply absorbing it. This is one of the strongest practical reasons to insist on the carpet area being stated in the agreement: it is not just information, it is the figure that measures whether you received what you were sold. Keep the agreed carpet area on record, and if the delivered flat measures short, the shortfall is a claim you can make rather than a loss you must accept. The protection only works, though, if the number was written down in the first place.

How do I check the area before I buy?

Get every area in writing and reduce each flat to a price per carpet foot before you compare.

1. Ask for the carpet area, the built up area and the super built up area separately.
2. Calculate the loading factor as the gap between super built up and carpet area.
3. Divide the total price by the carpet area to get the price per usable foot.
4. Compare competing flats on price per carpet foot, not the super built up rate.
5. Confirm the carpet area is recorded in the agreement for sale, not just a brochure.
6. Note that a shortfall against the agreed carpet area is refundable with interest.
7. Keep the agreed carpet area on record to measure the flat you finally receive.

How does this fit the undivided share and the agreement for sale?

Carpet area describes the space inside your flat, and it sits alongside two other things a Bengaluru buyer should pin down, the land your flat carries and the contract that records it. Our guide to the undivided share of land a flat buyer should check covers the proportionate land that comes with the flat, a different measure from its floor area, and our note on the sale agreement and the sale deed explains the document where your carpet area should be recorded. If you are comparing flats in a project such as Aparna Wonderwoods in Mallasandra, ask for the carpet area of each specific unit rather than the project's headline sizes. The usable space, the land share and the agreement together describe what you are really buying, and carpet area is the part that decides how the flat lives day to day.

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, while super built up area adds the walls, balcony and a proportionate share of common spaces such as lobbies and staircases. Super built up is the larger, saleable figure builders often quote, but only the carpet area is space you can actually use and furnish.

What is a loading factor in Bengaluru? The loading factor is the extra area added to carpet area to reach super built up area, as a percentage of the carpet. In Bengaluru it commonly runs thirty to forty percent, so a flat sold on super built up can have a carpet area only about two thirds of that. Ask for the loading to compare flats fairly.

Does RERA require sale on carpet area? Yes. RERA requires residential flats to be sold on carpet area, with the carpet area clearly disclosed, so buyers are not sold on an inflated super built up figure alone. Some builders still show super built up area in brochures, but the number that governs the sale is the carpet area, and you are entitled to it in writing.

What if the delivered carpet area is less than agreed? If the actual carpet area is less than what the agreement for sale recorded, the framework provides for the builder to refund the excess amount you paid, with interest. This is a strong reason to insist the carpet area is written into the agreement, because that figure is what measures whether you received the space you were sold.

Last updated 2026-08-30. PropNewz Team.