Carpet Area vs Super Built-up Area in Bengaluru: Which to Pay For
Is the bigger area number the bigger home? Learn carpet, built-up and super built-up area, what RERA requires, and how to compare flats in Bengaluru.
Written by
Justin
14 October 2026 · 5 minutes read
Carpet Area vs Super Built-up Area: Which Number Should a Bengaluru Buyer Pay For?
Is the flat with the bigger number in the brochure really the bigger home?
Not always. Imagine a buyer comparing two flats. Flat A is advertised at 1,200 sq ft and Flat B at 1,000 sq ft. Flat A looks bigger and cheaper per square foot. But Flat A’s number is its super built-up area, while Flat B’s is its carpet area. Once both are measured on the same basis, the “smaller” flat gives more usable space for each rupee. The brochure number hadn’t lied. It simply measured something different.
Quick answer
Carpet area is the usable floor space inside your flat. Built-up area adds the thickness of walls and usually your balcony. Super built-up area adds a share of common areas such as lobbies, lifts and staircases. RERA defines carpet area and requires the agreement for sale to state it, so compare flats and prices on carpet area.
What are the three area types?
Area type | What it includes | Size compared with carpet area |
|---|---|---|
Carpet area | Net usable floor area, including internal partition walls | Smallest |
Built-up area | Carpet area plus external walls, and usually balconies and ducts | Larger |
Super built-up area | Built-up area plus a share of common areas (lobbies, lifts, stairs, clubhouse) | Largest |
How much bigger the other two are varies from project to project, so ask the builder for the exact figures, not a rule of thumb.
How does RERA define carpet area?
RERA defines carpet area as the net usable floor area of an apartment. It excludes:
external walls
service shafts
exclusive balcony or verandah area
exclusive open terrace area
It does include the area covered by the apartment’s internal partition walls. This definition is the same across the country, which makes two projects comparable.
What does RERA require builders to state?
RERA requires the agreement for sale to specify the carpet area of the apartment, and sales are meant to be priced on that basis. This protects buyers from paying for space they can’t use, and lets them compare projects on the same footing. A brochure or ad can still show super built-up area, but your agreement should clearly state the carpet area.
How do I compare two flats fairly?
Work out the price per square foot of carpet area for each flat. Example, with illustrative figures:
Flat A | Flat B | |
|---|---|---|
Advertised area | 1,200 sq ft (super built-up) | Carpet area shown |
Carpet area | 780 sq ft | 900 sq ft |
Total price | ₹96 lakh | ₹1.05 crore |
Price per sq ft on the advertised number | ₹8,000 | n/a |
Price per sq ft of carpet area | about ₹12,308 | about ₹11,667 |
Flat B costs more in total, but it gives more usable space at a lower cost per square foot of carpet area. Also check the carpet-to-super built-up ratio (carpet area divided by super built-up area). In this example, Flat A’s is 65%, so about 35% of what you pay for is common area and walls. The ratio shows how efficiently the space is planned.
What if the carpet area delivered is less than the agreement?
Under RERA’s model agreement format, the builder must confirm the final carpet area after the occupancy certificate. If the area is reduced, the price is recalculated and the excess money is refunded with interest. If it increases, the builder can ask for the extra amount at the agreed rate. The agreement format commonly allows a small variation (up to 3%), and the refund timeline is stated in your agreement. The model agreement uses 45 days, but state formats can differ, so check yours.
What can I do about a shortfall? (6 steps)
Find the carpet area in your registered agreement and note the figure and the unit of measurement.
Measure the flat at handover. Measure each room, internal walls included, and exclude balconies, shafts and the external walls.
Compare with the agreement figure and calculate the difference and the percentage.
Write to the builder with your measurements and ask for a recalculation and a refund, as per your agreement.
Keep the paperwork: agreement, payment receipts, floor plans and correspondence.
File a complaint with K-RERA, or take legal advice, if the builder doesn’t respond.
What should Bengaluru buyers check before they buy?
K-RERA project page: it lists the project’s registration details, and the carpet area of each unit type is declared at registration.
Agreement for sale: confirm it states carpet area, balcony and utility areas separately, and the variation and refund clause.
Price per carpet sq ft: ask for it in writing and compare projects on it.
What the extra charges cover: common area share, parking, clubhouse and corpus are priced separately from your flat’s usable area.
Floor plan: check that room dimensions on the plan add up to the stated carpet area.
Paperwork: verify title and approvals, as in our legal opinion and mother deed guides.
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. Super built-up area adds walls, balconies and a share of common areas, so it is always larger.
Does RERA allow builders to sell on super built-up area?
RERA requires the agreement for sale to state the carpet area, and sales are meant to be on that basis. Builders may still mention other areas, but you should compare on carpet area.
Is the balcony part of the carpet area?
No. RERA excludes an exclusive balcony or verandah from carpet area, so it should be listed separately.
What if the flat I get has less carpet area than the agreement says?
The price should be recalculated and the excess money refunded with interest, as set out in your agreement. Measure at handover and raise it with the builder in writing.
What is a normal ratio between carpet area and super built-up area?
It varies by project. Ask the builder for the exact carpet and super built-up area, divide one by the other, and compare projects.
Can I complain to RERA about a carpet area shortfall?
Yes. You can file a complaint with K-RERA, or take legal advice on other options.
This article is for general education and is not financial, legal or insurance advice. Please consult a licensed insurance adviser before you decide.