Lesson 01 · Areas & the loading trick

Carpet vs built-up vs super built-up

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. The other 300 sq ft is your "share" of the lift, lobby and clubhouse — counted into your flat's size and 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 was sold for decades. Learn three terms and it can never happen to you again.

The three areas

1 · Carpet area

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. Excludes outer-wall thickness, balconies, and all shared space. The only number that reflects what you actually get.

2 · Built-up area

Carpet area plus the thickness of walls and your balcony/verandah. Usually 10–20% larger than carpet.

3 · Super built-up area

Built-up area plus your proportionate share of common spaces — lift, lobby, staircase, corridors, clubhouse. Also called "saleable area". The biggest number, and historically the one quoted to make flats sound larger.

The number that ties it together: loading factor

Loading is the padding added to your carpet area to reach the super built-up figure.

Loading factor = (Super built-up − Carpet) ÷ Carpet
= (1,300 − 1,000) ÷ 1,000 = 30%

A 30% loading means 30% of what you're paying for is space you can't furnish. Some projects push 40–50%. The single most useful question you can ask a salesperson: "What's the carpet area, and what's the loading factor?"

The protection you already have

Since RERA (2016), builders must legally quote and price on carpet area. And if the delivered carpet area turns out smaller than promised, the builder must refund the difference — with interest. The law only protects you if you know to check. Now you do.

Worked example. Two flats, both sold as "1,100 sq ft super built-up" at the same total price. Flat A has 10% loading → 1,000 sq ft carpet. Flat B has 37.5% loading → 800 sq ft carpet. Same headline, same price — Flat A gives you 200 sq ft more actual home. Loading decides, not the advertised size.

Quick check — 3 questions before you move on

1. Which area is the actual usable space inside your flat?

Built-up area

Carpet area

Super built-up area

Carpet area is the net usable space inside your walls — bedrooms, living, kitchen, bathrooms.

2. A flat has 1,000 sq ft carpet and is sold as 1,300 sq ft super built-up. The loading factor is:

13%

23%

30%

(1,300 − 1,000) ÷ 1,000 = 30%. Always compute on carpet, not on the bigger number.

3. ₹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:

₹6,667

₹5,000

₹5,400

Total = ₹60,00,000. Divide by the 900 sq ft you actually get: ₹6,667 — a third higher than advertised. This one calculation is the whole lesson.

Feeling confident? Take the full test →

📹 Video version of this lesson: coming to the Videos page — watch it explained in 60 seconds.