Lesson A1·03 · Areas & the loading trick
Carpet vs built-up vs super built-up
5 min read · 3 terms · 1 formula that protects lakhs
The trap, first
A builder shows you a "1,300 sq ft" flat at ₹6,000 per sq ft. You do the math — ₹78 lakh — and it feels fair. You sign.
What nobody told you: only 1,000 sq ft of that is space you can actually walk on and furnish. The other 300 sq ft is your "share" of the lift, lobby and clubhouse — counted into your flat's size, and into your price. Your real cost per usable foot isn't ₹6,000. It's ₹7,800.
This isn't fraud. It's how Indian real estate has been sold for decades. Learn three words and one formula, and it can never be done to you again.
See it before you read it
Three areas, nested. The smallest is what you live in. The biggest is what you pay for. The gap between them is the whole game.
The three areas
The net usable floor space inside your flat, wall to wall — the space you could literally lay a carpet on: bedrooms, living room, kitchen, bathrooms. It excludes external-wall thickness, balconies, and every shared space. This is the only number that reflects what you actually get to use.
Carpet area plus the thickness of the walls and your balcony/verandah. Usually 10–20% larger than carpet. You "use" some of this (the balcony), but not the walls.
Built-up area plus your proportionate share of all common spaces — lift, lobby, staircase, corridors, clubhouse, even the society office. Also called "saleable area." It's the biggest number, and historically the one builders quoted to make a flat sound larger than it lives.
The one number that ties it together: loading factor
"Loading" is the padding added on top of your carpet area to reach the super built-up figure. It's the single most useful number you can extract from any salesperson.
= (1,300 − 1,000) ÷ 1,000 = 30%
A 30% loading means 30% of what you're paying for is space you can't furnish. Reasonable projects sit around 25–30%. Some push 40–50% — and the higher it climbs, the more you're paying for corridors instead of rooms.
The two questions that end the trick
At every site visit, ask exactly this: "What is the carpet area, and what is the loading factor?" A straight answer means you can compare projects honestly. Hesitation, or "sir it's all the same," is itself the answer.
The protection you already have
Since RERA (2016), builders must legally quote and price on carpet area, not the inflated super built-up number. And if the carpet area delivered is smaller than what the agreement promised, the builder must refund the difference — with interest. But the law only protects the buyer who knows to check. Now you do.
Test yourself — 5 questions before the next lesson
Tap an answer. You'll see the correct one and why, instantly.
1. Which area is the actual usable space inside your flat — the space you could lay a carpet on?
Carpet area is the net usable space inside your walls — bedrooms, living, kitchen, bathrooms. It's the only number that reflects what you actually live in.
2. Under RERA, builders must legally quote and price a flat based on which area?
RERA (2016) mandates carpet-area pricing to stop inflated "saleable area" quoting. If delivered carpet is short, the builder must refund with interest.
3. A flat has 1,000 sq ft carpet and is sold as 1,300 sq ft super built-up. The loading factor is:
(1,300 − 1,000) ÷ 1,000 = 30%. Always compute loading on the carpet number, never on the bigger one.
4. ₹5,000/sq ft advertised on 1,200 sq ft super built-up; carpet is 900 sq ft. Your effective price per usable sq ft is:
Total = 1,200 × ₹5,000 = ₹60,00,000. Divide by the 900 sq ft you actually use: ₹6,667 — a third higher than the sticker. This one calculation is the whole lesson.
5. Two flats, same price, both "1,100 sq ft super built-up." Flat A: 10% loading. Flat B: 37.5% loading. Which gives more usable space?
A: 1,100 ÷ 1.10 = 1,000 carpet. B: 1,100 ÷ 1.375 = 800 carpet. Same price, 200 sq ft difference. Loading decides value, not the advertised size.
📹 Watch this explained in 60 seconds on the Videos page.