A Bengaluru buyer pays for a 1,200 square foot flat in Whitefield in 2026, moves in, and measures the space that is actually his: closer to 850 square feet. Nothing was stolen. The 1,200 was the super built-up area, a figure that includes his share of the lobby, staircase and corridors, while the 850 is the carpet area, the floor he can actually furnish. Understanding this gap is the difference between comparing flats honestly and paying for corridors you will never sit in.

The short answer. Under the real estate regulation law, a flat in Bengaluru must be sold and priced on carpet area, the net usable floor space within the walls, not on super built-up area, which adds a loaded share of common spaces. The difference, called loading, is commonly 25 to 40 percent, so a 1,200 square foot super built-up flat may offer only around 850 to 900 square feet of carpet area. The trade-off buyers must watch is that two flats with the same super built-up size can have very different carpet areas, and the one with less loading is the better buy.

Quick facts for July 2026: the real estate regulation law defines carpet area and requires developers to disclose it, the loading factor is the gap between carpet and super built-up area, and RERA registration details for a Karnataka project can be checked through the state regulator. Always compare flats on carpet area, not the marketing super built-up figure.

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

The three terms describe three different sizes, and only one is the space you actually use. Carpet area is the net usable floor area within the walls of your flat, the area you could literally lay a carpet on, excluding the thickness of external walls. Built-up area adds the thickness of the walls and usually the balcony, so it is larger than carpet area. Super built-up area goes further and adds your proportionate share of common areas like the lobby, staircase, lift and corridors.

Super built-up is therefore the largest figure and the one developers historically quoted, because a bigger number makes the per-square-foot price look lower. Carpet area is the smallest and the most honest, because it reflects what you can furnish and live in. The gap between them, expressed as a percentage, is the loading factor, and it is where a large part of the confusion, and occasionally the overpaying, happens.

How did RERA change the way flats are sold?

The real estate regulation law made carpet area the mandatory basis for selling and pricing a flat, ending the era when developers could quote only a flattering super built-up number. A developer must now disclose the carpet area, and the sale is meant to be transacted on that basis, which lets a buyer compare projects on a like-for-like measure of usable space. This is one of the law's most practical protections for an ordinary buyer.

In practice, marketing material still often leads with the super built-up figure, so the onus is on you to ask for and rely on the carpet area in the agreement. The carpet area should appear clearly in your builder-buyer agreement, and any mismatch between what is marketed and what is contracted is worth questioning, a point covered in our guide to builder-buyer agreement clauses to check in Bengaluru. The agreement, not the brochure, is what governs.

What is loading and how much is normal?

Loading is the extra area added to your carpet area to arrive at the super built-up figure, expressed as a percentage of the carpet area. If a flat has a carpet area of 900 square feet and a super built-up area of 1,200, the loading is about 33 percent. In Bengaluru, loading commonly ranges from around 25 percent in efficient projects to 40 percent or more in amenity-heavy developments with large lobbies, clubhouses and wide corridors.

Higher loading is not automatically bad, because it can reflect generous common areas and amenities you may value. But it is a cost, since you pay for that loaded space at the same per-square-foot rate as your living room. The key is transparency: know the loading before you buy, so you are choosing to pay for grand common areas rather than discovering after possession that a third of your paid area is corridor.

Why can two flats with the same size differ so much?

Because the same super built-up number can hide very different carpet areas, depending on the loading. A 1,200 square foot super built-up flat with 25 percent loading gives you about 960 square feet of carpet area, while another 1,200 square foot flat with 40 percent loading gives only about 860. That is a hundred square feet of real living space, a full small room, for the same quoted size and often a similar price.

This is exactly why comparing flats on the super built-up figure is misleading and comparing on carpet area is honest. When you shortlist two apartments, ask for the carpet area of each and compute the per-square-foot price on carpet, not super built-up. The flat that looks marginally smaller on paper may actually give you more usable space, and the one with a glossy big number may be mostly loading.

How do the area terms compare at a glance?

It helps to see the definitions and their typical relationship side by side, so you know which figure to demand and which to distrust. The table below sets out the position for a Bengaluru buyer in 2026.

Use this to structure your questions to the developer: ask for the carpet area, the super built-up area, and therefore the loading, on every flat you seriously consider.

How should you use carpet area when comparing homes?

Make carpet area your single comparison metric and everything becomes clearer. Compute each flat's price per square foot of carpet area, not super built-up, and you will often find the ranking of value shifts, because the flat with lower loading delivers more usable space per rupee. This is especially useful when weighing a ready-to-move flat against an under-construction one, where you can inspect the finished carpet space, a trade-off we explore in our guide to ready-to-move versus under-construction homes in Bengaluru.

Carpet area also matters for practical living: it determines how much furniture fits, how the rooms feel, and how the home functions day to day. A large super built-up number with heavy loading can disappoint on move-in, while a modest one with efficient loading can live larger than expected. Judge the home by the space you will use, and let the marketing figure fall where it may.

A seven-point area checklist for Bengaluru buyers

1. Ask for the carpet area of every flat you consider, not just the super built-up figure.
2. Compute the loading factor as the gap between carpet and super built-up area.
3. Compare flats on price per square foot of carpet area, not super built-up.
4. Confirm the carpet area is clearly stated in the builder-buyer agreement, not just the brochure.
5. Treat loading above roughly 35 percent as a prompt to ask what common areas you are paying for.
6. Remember built-up area sits between carpet and super built-up, and clarify which one is quoted.
7. Keep the agreed carpet area on record to check against the delivered flat at possession.

Work through these and you buy the space you actually get rather than the space a brochure implies. The buyers who feel short-changed at possession are usually those who compared super built-up numbers; the ones who are satisfied compared carpet area and knew exactly what they were paying for.

Is a flat sold on carpet area or super built-up area under RERA?

On carpet area. The real estate regulation law requires developers to disclose and sell flats on carpet area, the net usable floor space within the walls, rather than the larger super built-up figure they historically marketed. Marketing material may still lead with super built-up, so rely on the carpet area stated in your agreement, which is the legally governing figure for the transaction.

What is a good loading factor in Bengaluru?

Loading commonly ranges from about 25 percent in efficient projects to 40 percent or more in amenity-heavy ones. A lower loading means more of your paid area is usable carpet space, so a loading around 25 to 30 percent is generally more efficient. Higher loading is not automatically bad if you value large common areas, but you pay for that space, so know the figure before buying.

How do I calculate carpet area from super built-up area?

Carpet area is the super built-up area reduced by the loading. If a flat has 1,200 square feet super built-up and 33 percent loading, the carpet area is roughly 900 square feet. Ask the developer for both figures, and if only super built-up is quoted, ask for the loading percentage so you can work back to the usable carpet area before you compare or commit.

Why is carpet area smaller than the size I was quoted?

Because the size quoted is usually the super built-up area, which adds your proportionate share of common areas such as the lobby, staircase and corridors to the usable space inside your flat. Carpet area is only the floor within your walls, so it is naturally smaller. The gap is the loading factor, and it is why you should always confirm the carpet area before buying.

Last updated 2026-07-01. PropNewz Team.