Property listings in India use three different measurements: carpet area, built-up area, and super built-up area. A 3BHK might be listed as 1,650 sqft carpet, but 2,200 sqft super built-up. What’s the difference? And which one matters for your money? This guide cuts through the jargon and shows you the real numbers.
The Three Area Types: A Visual Breakdown
Imagine a 3BHK apartment. It has a living room, kitchen, two bedrooms, two bathrooms, a balcony, and a corridor inside. Here’s how builders measure each area type:
| Area Type | What It Includes | Typical % | Example for 1,650 sqft Carpet |
|---|---|---|---|
| Carpet Area | Bedrooms, bathrooms, living room, kitchen, balcony (all interior spaces you can walk on or use) | 100% baseline | 1,650 sqft |
| Built-Up Area | Carpet area + wall thickness (outer walls, internal partition walls) | 110–125% of carpet | 1,815–2,063 sqft |
| Super Built-Up Area | Built-up area + common areas (hallway, lobby, staircase, lift, gym, pool, parking garage) | 130–165% of carpet | 2,145–2,723 sqft |
Carpet Area: What You Actually Own
Carpet area is the most important number for you. It’s the area inside your flat where you can walk, sleep, cook, and shower. Walls don’t count because they’re shared with neighbors and the building.
Key point: You own the carpet area, not the walls. The builder owns the walls and the common areas.
In a property agreement, the carpet area is legally binding. If the agreement says 1,650 sqft carpet, the builder must give you exactly that—not 1,600 sqft. If they deliver less, you can claim compensation from RERA.
Carpet area is also what you’ll use to calculate property tax (charged per sqft of carpet area) and rental yield (rent divided by carpet area = rental yield%).
Built-Up Area: Carpet + Your Walls
Built-up area includes the carpet area plus the thickness of your apartment’s outer walls and internal partition walls. These walls are part of the building’s structure, so they’re technically shared with the builder and the society.
- Outer walls (facing the balcony or street) = typically 6–9 inches thick
- Internal partition walls (between bedrooms, bathrooms, kitchen) = typically 4–6 inches thick
Wall thickness varies by building type. A modern RCC frame structure has thinner walls (4–6 inches) than an older load-bearing structure (9–12 inches).
Why does built-up area matter? It’s used for some administrative purposes (like property registration in a few states) and it helps you understand the “true footprint” of your space. A 1,650 sqft carpet with 200 sqft of walls means your apartment actually occupies 1,850 sqft of the building.
Super Built-Up Area: The Developer’s Favorite
Super built-up area is where confusion sets in. It includes everything: your carpet area, your walls, AND a share of all common areas in the building.
Common areas include:
- Lobby and corridor in your building
- Staircase and lift shaft
- Gym and swimming pool
- Parking garage (your share based on assigned spots)
- Balcony of the building’s ground-floor shops
- Terraces and landscaping
- Property manager’s office
Builders use super built-up area to justify prices. A project might advertise a 3BHK as “from ₹2 Cr” but when you dig deeper, that’s 2,400 sqft super built-up (which is only 1,600 sqft carpet). The per-sqft price jumps from ₹1.2L/sqft (carpet) to ₹83K/sqft (super built-up)—sounding cheaper than it actually is.
Real Example: A 3BHK in Bangalore
Let’s say you’re looking at Prestige Tech Cloud, a project in Devanahalli, Bangalore.
- Carpet area: 1,650 sqft (bedrooms, kitchen, living room, balcony)
- Built-up area: 1,900 sqft (adds ~250 sqft of wall thickness)
- Super built-up area: 2,300 sqft (adds ~400 sqft for your share of lobby, lift, gym, parking)
- Price: ₹1.65 Cr
What does ₹1.65 Cr mean?
- Per carpet sqft: ₹1.65Cr ÷ 1,650 sqft = ₹1 L/sqft (the real rate)
- Per built-up sqft: ₹1.65Cr ÷ 1,900 sqft = ₹87K/sqft (looks cheaper, but misleading)
- Per super built-up sqft: ₹1.65Cr ÷ 2,300 sqft = ₹72K/sqft (sounds cheapest, but you don’t own most of this area)
Always compare projects using carpet area rates, not super built-up. A project quoting ₹72K/sqft super built-up might actually be ₹1L/sqft carpet—the same as competitors.
What Varies by State and Builder?
Super built-up area ratios vary:
| Scenario | Super Built-Up / Carpet Ratio | Why |
|---|---|---|
| Small apartment in high-density city (Mumbai, Bangalore) | 1.4–1.5x | More shared corridors, smaller units means higher common-area allocation per unit |
| Large villa or townhouse in tier-2 city | 1.1–1.2x | Fewer common areas; more of the building is private |
| Luxury high-rise with lots of amenities | 1.6–1.8x | Gym, pool, spa, multiple lounges = more common area |
| Budget project with minimal amenities | 1.2–1.3x | Only staircase, lobby, no gym or pool |
Read the project brochure: it should disclose the ratio. If it says “super built-up area = 1.5x carpet area”, you know what to expect.
Which Area Do You Pay Property Tax On?
This varies by state, so check your specific municipality:
- Karnataka (BBMP Bangalore): Property tax is based on carpet area.
- Maharashtra (BMC Mumbai): Property tax is based on built-up area.
- Telangana (GHMC Hyderabad): Property tax is based on carpet area.
The moral: different states, different rules. Ask the builder’s finance team which area is used for property tax in your city.
Common Mistakes Buyers Make
- Comparing projects by super built-up price: Two projects quote ₹60K/sqft and ₹70K/sqft super built-up. But if the first has a 1.6x ratio and the second a 1.4x ratio, the true carpet-area prices are ₹96K/sqft and ₹100K/sqft. They’re actually close.
- Forgetting about parking allocation: Super built-up area includes your share of the parking garage. If you have 2 assigned spots, you’re paying for that garage space. Check: what’s your parking ratio? (1.5 spots per unit is standard; some projects offer 1 spot or 2 spots.)
- Assuming all common areas are usable: You pay for a share of the gym, but the gym might only be open 6am–10pm. You pay for the pool, but it might be closed for cleaning twice a month. Read the bylaws to understand what you actually get access to.
- Not checking area consistency across documents: Brochure says 2,200 sqft super built-up. Agreement says 2,150 sqft. That 50 sqft difference might mean ₹5–10L in price. Reconcile all documents before signing.
Frequently Asked Questions
Do I own the common areas (gym, pool, parking garage)?
Legally, yes—you own a fractional share. If the building has 100 units and there’s one gym, you own 1/100th of the gym. But you don’t own it alone. Common areas are managed by the society (residents’ association), and you pay maintenance charges to keep them running.
Can builders claim larger super built-up area than reality?
Yes, and this is a common trick. RERA requires disclosure of carpet area (binding), but super built-up area can be vague. Always verify: super built-up area / carpet area should not exceed 1.8x. If a project claims 2,600 sqft super built-up for a 1,500 sqft carpet unit (1.73x ratio), it’s legitimate. If it claims 3,000 sqft (2x ratio), something’s off.
Is balcony area included in carpet area?
Yes, in India. Carpet area typically includes the balcony (usually 40–80 sqft for a 3BHK). Some builders use “net carpet area” (excluding balcony) to show smaller numbers—check the definition in the agreement.
Why do builders advertise super built-up area instead of carpet?
Because it’s larger and makes the price look cheaper (₹60K/sqft super built-up vs ₹1L/sqft carpet for the same unit). It’s a marketing tactic. Always ask for carpet-area pricing to compare fairly.
If I’m renting out my flat, which area affects rent?
Carpet area. Rent is quoted per carpet sqft (e.g., ₹100/sqft/month × 1,650 sqft = ₹1.65L/month). Tenants pay for the space they use, not the building’s shared walls and lobby.
Next Steps: Use This Knowledge to Negotiate
Now that you understand the three area types, (1) always compare projects by carpet-area price, not super built-up. (2) Request the actual ratio (super built-up ÷ carpet) in writing from the builder. (3) Check what area is used for property tax in your city. And (4) use our EMI calculator based on carpet area to see your true cost. Once you’ve verified the builder and understood the area, read our guide on 7 clauses to watch in the agreement.