Quick answer: Carpet area is the actual usable floor space inside your home — where you place furniture and walk around. The built-up area adds wall thickness and balconies. Super built-up area adds your proportionate share of all common spaces — lobbies, staircases, corridors, and amenity areas. In Bangalore, the super built-up area is typically 25–40% larger than the carpet area. Under RERA, all property sales must be priced on carpet area — not super built-up.
If you’ve been looking at villas or apartments in Bangalore, you’ve seen all three numbers in brochures and listings. Understanding the difference isn’t just academic — it determines whether the ₹6,500/sq.ft you’re being quoted is actually good value, or whether you’re paying a premium for lobbies and staircases.
The Three Definitions — Clearly Explained
Carpet Area
The net usable floor area inside your home — literally the space where you could lay a carpet. It includes all rooms, internal walls, and passages inside the unit. It excludes external walls, balconies, terraces, and service shafts.
RERA (Real Estate Regulation and Development Act) defines carpet area precisely under Section 2(k) as the net usable floor area, excluding external walls, balcony/verandah, and service shafts — but including internal partition walls.
This is the area you actually live in.
Built-Up Area
Carpet area plus the thickness of external walls, balconies, and utility areas within your unit boundary. Typically 10–20% more than carpet area depending on wall thickness and balcony size.
Built-up area is your unit’s full footprint — including the walls that enclose it.
Super Built-Up Area
Built-up area plus your proportionate share of all common areas in the project — entrance lobbies, lift shafts, staircases, corridors, generator rooms, security cabins, and in some cases clubhouse area. This is the number historically used by builders to price and sell property in India.
In Bangalore, super built-up area is typically 25–40% larger than carpet area. On a 4 BHK villa of 2,000 sq.ft carpet area, the super built-up area could be quoted as 2,500–2,800 sq.ft.
How This Plays Out in a Villa vs Apartment
This is where it gets villa-specific — and where most guides miss the point.
For apartments, the super built-up loading is significant because common areas (lifts, lobbies, multiple staircases, generator rooms) are shared among many units in a high-rise. Loading factors of 30–40% are common in Bangalore’s apartment projects.
For villas in a gated community, the loading factor is typically lower — 15–25% — because common areas are spread across fewer shared elements (the gate, club road, community clubhouse). A villa’s “super built-up” mostly includes your private plot coverage plus a smaller share of community infrastructure.
This means: on a per-sq.ft basis, a villa buyer gets more usable space per rupee than an apartment buyer quoted at the same super built-up rate. But you still need to verify the carpet area — because not all villa developers calculate loading the same way.
The RERA Rule — And How It’s Still Being Misused
Under RERA, all residential property sales must be priced on carpet area — not super built-up area. This has been the law since 2016. Karnataka RERA enforces this for all registered projects.
What still happens in practice:
Some developers quote price per sq.ft on super built-up area in their brochures and marketing material — then include the carpet area figure in the fine print of the RERA-registered builder-buyer agreement. The headline price looks cheaper; the actual price per usable sq.ft is higher.
Others show carpet area in the agreement but set a loading factor that isn’t clearly disclosed. A 4 BHK villa quoted at 2,800 sq.ft super built-up with 30% loading has only 1,960 sq.ft of actual carpet area — not the 2,200 sq.ft the buyer imagined.
The rule: Always ask for the RERA carpet area figure. Compare projects on price per sq.ft of carpet area — not super built-up. That is the only apples-to-apples comparison.
A Worked Example: Two Villas, Same Price
| Project A | Project B | |
| Quoted area | 3,000 sq.ft SBA | 2,600 sq.ft SBA |
| Price per sq.ft | ₹6,500/sq.ft | ₹7,500/sq.ft |
| Total price | ₹1.95 Cr | ₹1.95 Cr |
| Loading factor | 35% | 20% |
| Carpet area | 2,222 sq.ft | 2,167 sq.ft |
| Price per sq.ft (carpet) | ₹8,775 | ₹9,000 |
At the same total price, Project A looks cheaper per super built-up sq.ft — but the actual carpet area difference is only 55 sq.ft. The 35% loading on Project A versus 20% on Project B means you’re paying for significantly more common area in Project A.
Always force the comparison to carpet area before deciding.
What to Ask the Developer
Before signing any agreement, ask these three questions:
- What is the RERA carpet area of this specific villa? This number must appear in the builder-buyer agreement. If the developer won’t give you this number clearly, that is a red flag.
- What is the loading factor — and what does it include? Ask them to explain what common areas are included in the super built-up calculation. Clubhouse area, for example, is sometimes included and sometimes not — this significantly affects the loading percentage.
- Is the price in the agreement based on carpet area or super built-up? Under RERA it must be carpet area — but verify this in the actual agreement document, not just the brochure.
Why This Matters More Than Most Buyers Realise
On a ₹3 crore villa with a 30% loading factor, you are paying approximately ₹69 lakh for common areas and walls — not for the home you live in. That’s not inherently wrong, but you should know exactly what you’re buying.
When comparing two projects at similar price points, always convert to price per sq.ft of carpet area. It is the only number that tells you what you’re actually paying for usable space.
For a complete list of what to verify before signing any villa agreement, read Documents Needed to Buy a Villa in Bangalore and Red Flags in a Builder-Buyer Agreement.
This article is for informational purposes only. RERA definitions and regulations are subject to amendment. Always refer to the Karnataka RERA portal and consult a property lawyer for the most current guidance.
