Carpet Area, Built-Up and Super Built-Up: What You Are Actually Buying
The difference between carpet area, built-up area and super built-up area, what RERA requires builders to disclose, how loading works in Bangalore, and how to verify the area you were sold.
Updated · 6 min read · by HomeGyan certified engineers
The short answer
- Carpet area is the usable floor area inside your walls. It is the only figure RERA allows a builder to sell on.
- Built-up area adds the walls and balcony. Super built-up adds your share of lobbies, staircases, lifts and the clubhouse.
- The gap between carpet and super built-up is "loading", commonly 25–40% in Bangalore. At 40% loading, a "1,500 sqft" flat has roughly 900 sqft of usable space.
- Price per square foot is only comparable between two flats if both are quoted on the same basis. Comparing a carpet-area rate against a super-built-up rate makes the worse deal look cheaper.
- Areas can be physically measured at handover. A shortfall against the agreement is a contractual issue, and it is far easier to raise before you sign possession.
The three measurements, precisely
These three terms describe the same apartment and can differ by more than a third. Builders are not free to define them however they like — the Real Estate (Regulation and Development) Act defines carpet area specifically.
| Measurement | Includes | Excludes |
|---|---|---|
| Carpet area | Usable floor inside the flat, including internal partition walls | External walls, service shafts, exclusive balcony, exclusive open terrace |
| Built-up area | Carpet area plus external walls and balcony | Common areas outside your flat |
| Super built-up area | Built-up area plus a proportionate share of lobbies, staircases, lifts, clubhouse and other common amenities | Nothing meaningful — this is the largest figure |
What RERA requires
The Act defines carpet area as the net usable floor area of an apartment, excluding the area covered by external walls, areas under service shafts, and exclusive balcony or open terrace area — while including the area covered by internal partition walls.
The practical consequence is that a builder must disclose and sell on carpet area. Marketing material may still quote super built-up, and often does, because the per-square-foot rate looks lower against a bigger number. Your agreement is the document that matters.
How loading distorts a price comparison
Loading is the percentage added to carpet area to reach super built-up. In Bangalore it commonly runs 25–40%, and there is no cap on it.
Two flats advertised at the same rate per square foot can differ substantially in what you actually get to live in.
| Advertised (super built-up) | Loading | Approx. carpet area | Effective rate at ₹8,000/sqft advertised |
|---|---|---|---|
| 1,500 sqft | 25% | ~1,125 sqft | ₹10,667 per usable sqft |
| 1,500 sqft | 33% | ~1,005 sqft | ₹11,940 per usable sqft |
| 1,500 sqft | 40% | ~900 sqft | ₹13,333 per usable sqft |
Verifying the area you were sold
- Find the carpet area figure in your sale agreement — not the brochure. That is the contractual number.
- Measure the usable floor at handover, room by room, and compare against it. Internal partition walls count; external walls do not.
- Check whether balconies and any private terrace have been included in the carpet figure. They should not be.
- Note any shortfall in writing before signing the possession letter. Once possession is accepted, a measurement dispute is much weaker.
- Ask for the approved floor plan and confirm the built layout matches it — a moved wall changes the area you paid for.
Where this fits in an inspection
Area verification is a measurement task, not an opinion, and it belongs alongside the defect inspection because both have the same deadline: the moment you sign possession, your leverage drops sharply.
A dated, independent record of both the measured area and the physical defects is what turns a disagreement into a documented claim.
Frequently asked questions
Is loading illegal?
No. Charging for a share of common areas is normal and not prohibited. What RERA changed is the disclosure basis: the builder must state carpet area, so you can see what proportion of the price buys usable space.
What counts as a reasonable loading percentage?
There is no legal limit. In Bangalore, 25–30% is common in older projects and 30–40% in newer amenity-heavy developments. A higher figure is not automatically bad — it often reflects genuinely larger common facilities — but it should be visible to you before you compare rates.
What if the measured carpet area is smaller than the agreement says?
That is a contractual shortfall and should be raised in writing before you accept possession. Sale agreements commonly contain a clause covering variation and compensation; read that clause first, and document the measurement independently.
Do balconies count in carpet area?
An exclusive balcony or verandah is excluded from carpet area under the Act, as is an exclusive open terrace. They are frequently included in built-up and super built-up figures, which is one reason those numbers run so much higher.
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