East Bengaluru buyer answers
Carpet area vs super built-up area: what does RERA say a flat is?
Direct answer: Under the RERA Act, carpet area is the flat's net usable floor area, including internal walls. It excludes external walls, service shafts, exclusive balconies and exclusive terraces. "Super built-up area" isn't defined in the Act at all. It's a sales figure that loads a share of lobbies, lifts and clubhouse onto your flat.
Disclosure: acre&key’s advice is free to buyers; we are an authorised sales partner for some projects and may be paid by the developer.
Verify with your lawyer: This page explains the RERA Act's definitions, not legal advice. Before you sign, have your own property lawyer check how the agreement for sale states the carpet area and what it says about any shortfall at possession.
Ask three Bengaluru sales offices how big a "1,500 sq ft 3BHK" is, and you may get three different floors. One is quoting carpet area, another built-up, the third super built-up. Only one of those terms has a definition in law. Once you know which one, a lot of brochure arithmetic stops working on you.
What exactly counts as carpet area under RERA?
Section 2(k) of the Real Estate (Regulation and Development) Act, 2016 defines carpet area as "the net usable floor area of an apartment, excluding the area covered by the external walls, areas under services shafts, exclusive balcony or verandah area and exclusive open terrace area, but includes the area covered by the internal partition walls of the apartment" (RERA Act, hosted by K-RERA).
Item by item:
| Part of the flat | In RERA carpet area? |
|---|---|
| Floor you can walk on inside the flat | Yes |
| Internal partition walls (between your rooms) | Yes |
| External walls | No |
| Service shafts (plumbing, electrical ducts) | No |
| Your exclusive balcony or verandah | No, though it's usually listed separately |
| Your exclusive open terrace | No, though it's usually listed separately |
| Lobby, staircase, lift well, clubhouse share | No. These are common areas |
The Act's explanation says "exclusive balcony or verandah area" means a balcony attached to your flat "meant for the exclusive use of the allottee". The same logic covers an exclusive open terrace.
Why isn't "super built-up area" in the law?
Because it isn't a measurement of your flat. It's a pricing convention. Builders typically take the carpet area, add walls and balconies (often called "built-up"), and then add a share of the common spaces. The Act separately defines "common areas" as including staircases, lifts and lift lobbies, fire escapes, basements, terraces, parks, play areas, "open parking areas" and community facilities (s.2(n)). Common areas belong to everyone in the project. The Act doesn't carve them up into "your square feet".
How much a project loads onto carpet area varies from project to project, and there's no legal percentage. Anyone quoting a "standard" loading for East Bengaluru is giving you an opinion, not a rule. Work it out yourself.
How do I work out the loading on a project?
You need two numbers from the builder for the same unit: RERA carpet area and super built-up area.
- Loading % = (super built-up − carpet) ÷ carpet × 100.
- Effective price per sq ft of carpet = total agreement price (before taxes) ÷ carpet area.
The second number is the one to compare across projects. A project quoting a lower "per sq ft" on super built-up can still cost more per usable square foot than its neighbour. Taxes, parking and other charges sit on top; our page on hidden costs beyond the base price lists them. For the parking line, here is what RERA says about selling car parking separately.
Get both figures in writing. If a sales office won't give you the carpet area of a specific unit, that tells you something too.
Where can I find the carpet area a builder registered?
Builders registering a project with Karnataka RERA disclose unit details as part of the registration. Search the project on rera.karnataka.gov.in and open its details; our guide to checking a project on the Karnataka RERA website walks through it. What's displayed varies by project and by when it was registered. If the unit-wise carpet area isn't visible, ask the builder for the RERA-filed figure and the page it comes from.
Your agreement for sale should also state the carpet area. The Act requires the agreement to follow a prescribed form and to specify the particulars of the apartment (s.13(2)). If the agreement only mentions super built-up area, raise it before signing. Our page on what to check in the builder's sale agreement covers the other clauses.
Does the price have to be based on carpet area?
The Act ties disclosure and the agreement to carpet area. Whether a Karnataka builder may still quote a price per super built-up square foot in marketing depends on the state's rules and regulations, and we haven't seen rule text that settles it, so we're not stating an answer here. What you can always do is ask for the total price and the carpet area, and divide.
What if the flat I get is smaller than the carpet area in my agreement?
Measure at possession. Have someone you trust measure room by room, leaving out external walls, shafts and exclusive balconies or terraces as the definition says, and compare the result with the agreement. Possession is also when you should see the occupancy certificate; our page on OC and CC explains why. Use our flat possession inspection checklist for the rest of the handover.
If there's a shortfall, start with a written query to the builder that includes your measurements. If that doesn't resolve it, Section 31 lets any aggrieved person complain to Karnataka RERA (K-RERA FAQ). Whether compensation follows depends on your agreement and the Authority's view, so we won't predict an outcome.
How should I compare two East Bengaluru projects fairly?
Put both on one sheet, with everything on carpet area:
- The carpet area of the exact unit
- Exclusive balcony or terrace area, on its own line
- The total price before GST and registration
- What you're effectively paying per carpet sq ft
- Common amenities you'll actually use. A big clubhouse loading is only "value" if you use the clubhouse.
Two projects in the same corridor can market similar "sizes" with very different usable floors. Carpet area is the only way to see it.
How much usable floor is in a "1,500 sq ft" flat?
It depends entirely on the loading. The figures below are invented to show the arithmetic. They aren't market data.
| Project A | Project B | |
|---|---|---|
| Quoted size (super built-up) | 1,500 sq ft | 1,450 sq ft |
| RERA carpet area (unit) | 1,050 sq ft | 1,120 sq ft |
| Loading on carpet | 42.9% | 29.5% |
| Total price before taxes | ₹1.20 crore | ₹1.20 crore |
| Price per carpet sq ft | ₹11,429 | ₹10,714 |
On the brochure, A looks bigger. On the floor you'll actually use, B gives you 70 sq ft more for the same money. Run this table on every shortlist.
What should you ask the sales office about area?
- What is the RERA carpet area of this unit number, and where in the RERA filing does it appear?
- What are the exclusive balcony and terrace areas, listed separately?
- Which figure does the agreement for sale use, and will it state carpet area?
- Is any part of the price expressed per super built-up sq ft, and what's the total in rupees?
Frequently asked questions
Is a balcony included in carpet area?
Not if it's your exclusive balcony. The RERA definition excludes "exclusive balcony or verandah area". Builders usually list it as a separate figure, so check both numbers.
Is super built-up area legal to quote?
The RERA Act doesn't define it. Your agreement and the RERA filing should give carpet area, so treat any super built-up figure as a sales number and convert to carpet before you compare.
What loading percentage is normal in Bengaluru?
There's no legal standard, and we don't publish a "typical" figure. Work it out for each project from the builder's own carpet and super built-up numbers.
Are internal walls part of carpet area?
Yes. The Act's definition specifically includes "the area covered by the internal partition walls of the apartment". External walls are excluded.
Should I measure the flat at possession?
Yes. Measure room by room using the RERA definition and compare it with the carpet area in your agreement. Raise any shortfall with the builder in writing first.
References
- Real Estate (Regulation and Development) Act, 2016, ss. 2(k), 2(n), 13, 31 (copy hosted by Karnataka RERA). https://rera.karnataka.gov.in/resources/staticpage/Real_Estate_Act.pdf, accessed 15 Oct 2026.
- Karnataka RERA, project search. https://rera.karnataka.gov.in/viewAllProjects, accessed 15 Oct 2026.
- Karnataka RERA, FAQs. https://rera.karnataka.gov.in/resources/staticpage/KARNATKA_FAQs.pdf, accessed 15 Oct 2026.