Carpet Area vs Built-Up Area vs Super Built-Up Area: What You Actually Pay For
Two flats are both advertised at 1,200 sq ft. One is priced at ₹5,000 per sq ft and the other at ₹5,200. The cheaper one looks like the better deal. But if the first flat gives you 850 sq ft of usable space and the second gives you 950, the second flat is cheaper per sq ft of space you can actually use.
This is the problem the three area terms create. Builders, brokers and listings use different measurements, and a buyer who compares them directly can end up paying for space they never use. This guide is for anyone shortlisting an apartment in India, especially first-time buyers. It explains what each term means, how the gap between them is created, and what to check in your documents.
The short answer
Carpet area is the net usable floor area inside the flat, including the thickness of internal walls. It excludes external walls, service shafts, and exclusive balcony and terrace areas.
Built-up area is the carpet area plus the walls and the balcony (and similar exclusive areas) attached to your flat.
Super built-up area is the built-up area plus a share of common areas such as lobbies, staircases, lifts and amenities.
Compare flats on carpet area. Under the RERA Act, 2016, carpet area is the only one of the three with a statutory definition. Super built-up area is a marketing figure.
What does each term mean?
Carpet area
Official fact. Section 2(k) of the RERA Act defines carpet area as the net usable floor area of an apartment. It excludes the area under external walls, service shafts, exclusive balcony or verandah, and exclusive open terrace. It includes the area covered by internal partition walls. (India Code: RERA Act, 2016)
In plain terms, it is the floor space inside your front door where furniture can actually go.
Built-up area
Built-up area is not defined in the RERA Act. In common industry use, it is the carpet area plus external wall thickness plus exclusive balconies and similar attached areas. Because it has no statutory definition, builders can include slightly different things. Always ask for the breakdown.
Super built-up area
Market usage, not a statutory term. Super built-up area (also called saleable or super area) is the built-up area plus a proportionate share of common areas. These can include staircases, lift lobbies, corridors, clubhouse and other shared facilities.
The RERA Act separately lists what counts as common areas: lifts, staircases and lobbies, common terraces, parks, play areas, water tanks and similar facilities (Section 2(n)). You do own a share of these. But you cannot live in them, which is why they should not be priced as if they were your usable floor space.
How the three areas compare
Carpet area
Built-up area
Super built-up area
Includes internal walls
Yes (under RERA)
Yes
Yes
Includes external walls
No
Yes
Yes
Includes exclusive balcony/terrace
No
Usually yes
Usually yes
Includes share of common areas
No
No
Yes
Defined in RERA Act
Yes, Section 2(k)
No
No
Usable for furniture and living
Yes
Partly
No
What is the loading factor, and why does it matter?
The loading factor is the gap between super built-up area and carpet area, expressed as a percentage. If a flat has 1,000 sq ft of carpet area and 1,300 sq ft of super built-up area, the loading is 30%.
HomeVerse analysis. A simple way to compare flats is the carpet-to-super ratio: carpet area divided by super built-up area. In the example above, that is 1,000 ÷ 1,300, or about 77%. A higher ratio generally means more of what you are shown is usable floor space. Two projects with the same super built-up area can have very different usable space.
Industry estimate. Loading varies widely by project type and design. Some published buyer guides put it anywhere from roughly a quarter to well over a third of carpet area. Treat that as a rough range, not a standard. Ask for the project's actual numbers rather than relying on a rule of thumb.
Worked example: same price, different value
Flat A
Flat B
Super built-up area
1,200 sq ft
1,200 sq ft
Carpet area
850 sq ft
950 sq ft
Total price
₹60 lakh
₹60 lakh
Price per sq ft (super built-up)
₹5,000
₹5,000
Price per sq ft (carpet)
about ₹7,059
about ₹6,316
Carpet-to-super ratio
about 71%
about 79%
Illustrative example only, not market data. The two flats look identical on a super built-up basis. On a carpet basis, Flat B gives you about 100 sq ft more usable space for the same money.
What does RERA say about selling on carpet area?
The RERA Act requires promoters to disclose the number, type and carpet area of apartments, along with exclusive balcony and terrace areas, when registering a project (Section 4(2)(h)). It also allows a promoter to take no more than 10% of the cost as an advance before signing and registering a written agreement for sale (Section 13). India Code: RERA Act, 2016.
What this means for buyers. The registered agreement for sale is where the area is fixed in writing, so it matters more than a brochure or an allotment letter. In one MahaREAT matter reported by a legal news site, the tribunal held that the carpet area stated in the executed agreement for sale prevailed over figures in earlier documents such as the allotment letter and draft agreement.
Several state RERA authorities have said publicly that apartments should be sold on carpet area. For example, UP RERA issued an advisory in June 2026 telling buyers to evaluate units on carpet area. Rules differ by state, so check what applies to your project's state authority.
Brochures and listings may still show super built-up area. Treat it as a marketing figure, and ask for the carpet area in the agreement.
Checklist: what to verify before you pay a booking amount
Ask for the carpet area of the exact unit, in sq ft and sq m, in writing.
Ask for balcony and terrace areas separately. They are not part of carpet area.
Check the project's RERA registration page on the state authority's website and match the unit's carpet area.
Compare the carpet area in the brochure, allotment letter and draft agreement for sale. They should match.
Calculate price per sq ft of carpet area and the carpet-to-super ratio for every flat you compare.
Read the area-variation clause in the agreement for sale. Understand how reductions and increases are handled and by when.
Compare against the sanctioned plan where you can, ideally with an architect or qualified professional.
Confirm what is included in the price (parking, club membership, other charges) so the comparison is like for like.
Comparing price per sq ft across different area types. One builder's super built-up rate is not comparable with another's carpet rate.
Treating the balcony as part of carpet area. Under RERA it is excluded and must be disclosed separately.
Relying on the brochure. The signed, registered agreement is what binds both sides.
Ignoring the efficiency of the layout. Two flats with equal carpet area can feel very different. Corridors, awkward corners and wasted space reduce usable room.
Assuming older rules still apply. In Maharashtra, the older MOFA carpet area definition counted balconies, while RERA excludes them. This is why figures in older paperwork may not match.
The HomeVerse perspective
HomeVerse helps buyers in Jaipur and Nagpur explore homes, compare options and get guidance through the home-buying journey. When you shortlist homes, comparing them on carpet area gives you a clearer, like-for-like view.
FAQs
1. What is the difference between carpet area and super built-up area?
Carpet area is the usable floor space inside your flat, including internal walls. Super built-up area adds external walls, attached balconies and a share of common areas. The extra part is the loading.
2. Should I buy a flat on carpet area or super built-up area?
Compare and price flats on carpet area. It is the statutory measure under the RERA Act, and your agreement for sale should state it.
3. Is the balcony included in carpet area?
Not under RERA. Exclusive balcony, verandah and open terrace areas are excluded and shown separately.
4. How do I calculate the loading factor?
Divide the super built-up area by the carpet area and subtract 1. For example, 1,300 ÷ 1,000 is 1.3, so the loading is 30%.
5. What if the final carpet area is less than the agreement says?
In Maharashtra's model agreement, the promoter must recalculate the price and refund the excess within the 3% cap. Check the variation clause in your own agreement.
6. Does built-up area include common areas like lobbies and lifts?
Usually not. Common area share is added when moving from built-up to super built-up area.
7. Where can I check a project's carpet area?
On the project's registration page on the state RERA website (RERA Rajasthan for Jaipur, MahaRERA for Nagpur), and in the agreement for sale.
Conclusion
The three terms describe three different things: the space you use, the space you own with walls and balcony, and the space the marketing counts. Pay for the first, understand the second, and treat the third as a reference. Ask for the carpet area in writing, check it against the registration page and the agreement, and compare flats on price per sq ft of carpet area.
Explore homes with HomeVerse.
This article is for general information and does not constitute legal, financial or investment advice. Rules, rates and market conditions change. Please verify details with the relevant authority or a qualified professional before making a decision.
