Carpet, built-up and super built-up area
last updated 2026-07-21
Carpet area is the net usable floor space inside a flat. Built-up area adds the walls and balcony (roughly 10–20% more), and super built-up area adds a share of common spaces (another 25–30%). Since RERA, new flats must be priced on carpet area — but an auction notice may still state built-up area and undivided share.
The three areas
| Term | What it covers |
|---|---|
| Carpet area (RERA) | The net usable floor space you can actually use — inside the flat, excluding balcony and common areas. The most honest measure. |
| Built-up area | Carpet area plus the walls and balcony — typically 10–20% more than carpet area. |
| Super built-up area | Built-up area plus a share of common spaces (lift, lobby, stairs, amenities) — often 25–30% above built-up. The "saleable" area builders once quoted. |
What RERA changed
Under the Real Estate (Regulation and Development) Act, 2016, builders must price and sell new flats on carpet area, not the inflated super built-up figure, and there are limits on how much the delivered carpet area may vary from what was promised. That transparency applies to new, RERA-registered projects.
Why it matters at auction
A bank-auction flat is usually a resale, and the sale notice often states the built-up area and the undivided share (UDS) of land rather than a RERA carpet area. If you compare that figure to a carpet-area price elsewhere, you are not comparing like with like — built-up overstates usable space. Knowing which area a notice quotes is essential to value a flat correctly, and it feeds directly into the flat-valuation method (built-up × construction rate + UDS × land rate). AuctionScope helps you read what a listing actually states so the comparison is honest.
Frequently asked questions
What is the difference between carpet area and built-up area?
Carpet area is the net usable floor space inside a flat, excluding walls, balcony and common areas. Built-up area adds the walls and balcony, so it is typically 10–20% larger than the carpet area.
Does RERA require carpet-area pricing?
Yes. Under RERA, builders must price and sell new flats based on carpet area rather than super built-up area, with limits on how much the delivered carpet area may vary. This applies to RERA-registered projects.
Which area does a bank auction notice use?
Often the built-up area and the undivided share of land, not a RERA carpet area. Check which one is stated before comparing the price to carpet-area figures elsewhere, or the comparison will be misleading.
Related terms
Sources
Rates, fees and procedures change — confirm the current position on the official portals below before you act.