Carpet Area and Super Built-Up Area: How to Read a Bangalore Flat's Real Size

Look at a brochure for a new apartment in Bangalore and the size printed on it will rarely be the floor space the family gets. Builders sell on one measurement, the law uses another, and the distance between them can run to a third of the quoted size. This article sorts out the vocabulary, shows how to compare projects on a fair basis and explains the buyer's position if the finished flat falls short.

One Flat, Three Measurements

Carpet area is the floor a household uses indoors, counting the thickness of walls that separate rooms. Built-up area takes that and adds the outer walls, the balconies and utility space, a measure that appears in some floor plans and in lender valuations.

Super built-up area goes a step further by adding a proportion of everything shared in the building: lobbies, corridors, lifts, staircases and the clubhouse. Price sheets and advertisements nearly always quote this one, usually under the label saleable area.

Only carpet area has a legal definition. The other two are trade habits, and builders choose which shared spaces to count, so one saleable figure can stand for quite different homes.

The RERA Definition

The RERA Act of 2016 deals with this in Section 2(k). Carpet area there means the net usable floor of an apartment, plus the walls dividing its rooms. The count leaves out external walls, service shafts, any balcony or verandah serving only that flat, and any open terrace serving only that flat.

A project's registration records how many apartments of each type it has and the carpet area of each. The agreement for sale ties the price to that figure. Balcony and terrace sizes are written separately, which means a large balcony can raise the bill without raising the carpet number.

Why the Gap Exists

The extra on top of carpet area is called loading, and it covers walls, balconies and the owner's portion of common spaces. People calculate it against either figure, so the same flat can show two different percentages.

Suppose a flat is sold at 1,300 square feet and its carpet area is 800 square feet. The 500 square feet of loading equals 38% of what is sold, yet 62% of what is usable. A buyer should find out which base the salesperson has in mind.

Carpet efficiency, the carpet figure as a percentage of the saleable one, is clearer. In this case it is about 62%. Anarock Research reports that Bangalore's average loading reached 41% of saleable area in early 2025, up from 30% in 2019. That leaves carpet efficiency near 59% in a typical launch.

Clubhouses, double-height entrance halls, extra lifts and broad corridors are behind the rise. A compact block with a handful of homes per level tends to load less. Loading matters after moving in as well, because most projects bill maintenance by saleable area.

Two Flats, One Quote

Dividing price by saleable area gives the rate on the sheet. Dividing price by carpet area gives what each usable foot costs, and that is the better number for choosing between projects.

Consider two flats, each 1,300 square feet at Rs. 9,000 a square foot, so Rs. 1.17 Crore apiece. The first has 845 square feet of carpet area, an efficiency of 65%. The second has 780 square feet, or 60%.

The first works out to about Rs. 13,850 for every usable square foot, and the second to Rs. 15,000, which is roughly 8% more. The first buyer also gets an extra 65 square feet, comparable to a small study. These figures are for illustration, but the method works for any shortlist.

The Karnataka RERA portal publishes a declared carpet size for each type of unit, which makes the sales team's claim easy to test. Pages for apartments in Whitefield and elsewhere carry sizes the builders publish, and those are saleable areas unless the page says otherwise.

When the Final Flat Differs

The RERA model sale agreement has a clause for this. Once the building is finished and the occupancy certificate arrives, the builder confirms the final carpet area and the price is adjusted at the agreed rate per square foot.

• A smaller flat earns the buyer a refund of the excess inside 45 days, plus interest at the rate in the rules
• A bigger flat lets the builder ask for more, though the rise cannot top 3% of the agreed size

Karnataka prescribes SBI's highest marginal cost of lending rate plus 2%. Anyone worried about a shortfall can get the flat measured before accepting possession. Under Section 14 a builder also cannot alter the approved plan or the flat's layout unless the buyer consents in writing, other than minor changes.

Matching Each Number to Its Job

Several figures run through one purchase, and each has a specific use.

• The sale price in the agreement rests on carpet area, while balcony, terrace and parking are priced individually
• Monthly maintenance is generally levied on saleable area
• The buyer's portion of the land follows the flat's size relative to the project
• A lender's valuer takes its own measurements and records carpet and built-up areas
• Furniture planning works best from the room dimensions drawn on the plan

Government charges depend on the property's value, and the guidance value acts as a minimum. In Karnataka, a property priced over Rs. 45 Lakhs attracts duty near 5.6% after cess and surcharge, and registration adds 2%. Those amounts can be added to a loan estimate in the EMI calculator.

Questions Worth Asking

Replies in writing to the following head off most arguments about size later.

• What are the carpet, balcony and saleable figures for this exact unit?
• Does the carpet figure agree with the portal entry for that unit type?
• What does one square foot of carpet area cost all in, and how do projects compare?
• How large is each room on the floor plan, given that identical carpet areas can hide small bedrooms?
• Which area do maintenance and the corpus fund use?
• Does the agreement carry the usual clause for a change in carpet size?

Visiting a sample flat is useful, but they often come with narrow furniture and no doors. Taking a tape to a bedroom and checking it against the plan is more reliable. The team can look up carpet areas for a shortlist if asked through the contact page.