Carpet area vs built-up area is the first comparison that separates a fair deal from an expensive one, and most buyers in Delhi only work it out after they have paid a token. A floor described as a 3 BHK can feel like a compact two-bedroom or a genuinely generous three-bedroom once you stand inside it. The difference is rarely the layout. It is which of the three area figures the seller is quoting, and what that figure includes.
This guide explains each number, shows where carpet area, built up area and covered area diverge on a builder floor specifically, and gives you a way to measure the space yourself before you commit.
What carpet area actually means
Carpet area is the net usable floor area inside a home. It is measured from the inner face of one wall to the inner face of the opposite wall, room by room, and added up. Under the Real Estate (Regulation and Development) Act, 2016, carpet area includes the area within internal partition walls. It excludes the thickness of external walls, service shafts, and the exclusive balcony, verandah and open terrace area attached to the unit.
That definition matters because it is the only area figure in Indian property law with a fixed meaning. Everything else is convention, and conventions vary by seller.
What built-up area adds
Built-up area takes carpet area and adds the thickness of the external walls, the internal and external plaster, and usually the balcony and utility areas. In practice, built-up area runs somewhere between ten and twenty per cent above carpet area on a typical floor, depending on how thick the walls are and how much balcony the floor has.
Two builders can quote the same flat as built-up area and mean two different things. One includes the balcony, the other does not. One measures to the outer face of the wall, the other to the centre line. This is exactly why a number that sounds precise can be soft.
Why super built-up area barely applies to a builder floor
Super built-up area adds a proportionate share of common areas to the built-up area. In a tower that loading can be substantial, because there is a lobby, a clubhouse, corridors on every floor, two lifts, a staircase core and often a podium to pay for. The loading is how a 900 square feet carpet flat gets sold as a 1,400 square feet apartment.
A builder floor is one whole floor on a single residential plot, and there is very little common area to load. You share a staircase, sometimes a lift, and the boundary of the plot. There is no clubhouse, no corridor, no lobby. So when a seller quotes a super built-up figure on a builder floor, treat it as a marketing number rather than a measurement. The useful comparison on a floor is carpet area against the covered area recorded in the sanctioned plan.
Carpet area vs built up area: the numbers side by side
| Area type | What it includes | What it leaves out | Who tends to quote it |
|---|---|---|---|
| Carpet area | Usable floor inside the walls, including internal partitions | External wall thickness, shafts, exclusive balcony and terrace | RERA-compliant disclosures, and a careful resale seller |
| Built-up area | Carpet area plus external walls, plaster, usually balcony and utility | Any share of common areas | Most builder floor sellers |
| Super built-up area | Built-up area plus a proportionate share of common areas | Nothing, by definition | Tower projects and brokers pricing against them |
| Plinth or covered area | The footprint of the built structure on each floor, as sanctioned | Open balconies and projections the plan treats separately | The sanctioned plan, the sub-registrar, the circle rate table |
The number that decides your paperwork
Here is the part almost no buyer checks. The area written into your sale deed is a covered area, and the circle rate for your colony is applied to that figure. It is not applied to the carpet area you measured with a tape. If the deed records a larger covered area than the floor plausibly has, you pay stamp duty on a number you did not get. If it records a smaller one, you may have a problem at resale or at the time of a loan valuation.
So there are three figures in play, not two: what you can use, what the deed says, and what the plan sanctions. A well-prepared builder floor will have all three close together and explainable. If the gap between them is wide, ask why before you sign anything. Our note on how the registry value of a builder floor is calculated walks through the arithmetic a sub-registrar actually applies.
How to measure carpet area yourself
You do not need a surveyor for this. A laser measure and half an hour will settle most of the argument. Work room by room and ignore the furniture.
- Measure each room from the inner face of the wall to the inner face of the opposite wall. Do not include skirting or wardrobes.
- Multiply length by breadth for each room and note the result separately.
- Measure the kitchen the same way, then the bathrooms. Bathrooms count, and they are often left out of a seller’s rough figure.
- Measure the balcony separately and keep it out of the carpet total. It is not carpet area.
- Add the room totals. That is your carpet area.
- Compare it with the number you were quoted. A gap of five per cent is normal measurement drift. A gap of twenty per cent is a different claim being made.
- Photograph the plan if you are shown one, and ask for the sanctioned plan in writing.
Why two 3 BHKs on the same street feel different
Three bedrooms and a drawing room is a description, not a standard. There is no legal definition of a 3 BHK. One floor fits a 3 BHK into a smaller covered area by trimming the third bedroom to a study, narrowing the corridor, or cutting the kitchen down to a galley. Another uses a wider plot and gives the same count with real rooms.
This is why the useful question is not how many bedrooms a floor has, but how much carpet area each bedroom gets and how wide the shared spaces are. A floor plan with a twelve foot wide drawing room and a nine foot wide one will photograph identically and live completely differently.
What to ask on the site visit
- Which area is this figure, exactly? Carpet, built-up or super built-up.
- Can I see the sanctioned plan for this plot?
- What covered area will the sale deed record?
- Is the balcony counted in the built-up area you have quoted?
- Which rooms are measured to the inner wall and which to the outer?
- Has the floor been measured by anyone independent, and is that report available?
If you are still working out how a floor differs from an apartment in the first place, start with what a builder floor is and how it is held. If you would rather compare actual floors, the builder floors we have in Vasant Kunj are a fair place to see how these numbers read on a real plan.
The short version
Carpet area is what you can walk on. Built-up area adds the walls. Super built-up area adds a share of things a builder floor mostly does not have. The deed records a covered area, and that is the figure your stamp duty and circle rate valuation follow.
Measure the floor yourself before you commit to anything. If the three numbers line up and the seller can explain the gaps, you are looking at a straightforward deal. If they cannot, you have found your answer early, which is the cheapest time to find it.
To see the covered areas and layouts we actually build, ask us for the plan and current availability and we will send what exists rather than a rounded number.
