Carpet vs super built-up: the 20% that isn't there.

Two brokers, one flat, two prices — twenty per cent apart. Neither is lying, exactly. They are quoting two different areas. And until you understand the difference, you cannot know what a Mumbai home actually costs.

Three areas, one home

Every apartment has a carpet area — the usable floor within your walls, the space you can actually lay a carpet on. It is defined and, since RERA, the only area a developer may legally sell on. Then there is built-up (carpet plus the walls) and super built-up — carpet plus a share of the lobby, lifts, staircases, and sometimes the gym and the swimming pool. Super built-up can be twenty to forty per cent larger than carpet, and it is the number brokers love to quote, because it makes the ₹/ft² look smaller.

The one number that can't be inflated

There is a figure no one can spin: the registered price. When a sale is finally signed, the government records the consideration and the carpet area in the IGR Index-II. Divide one by the other and you get the registered carpet ₹/ft² — what a home genuinely traded for, per usable foot. It is the same basis for every flat, so it is the only honest way to compare two of them.

This is the entire premise of Carpet & Key. We price every home on registered carpet ₹/ft², we show you the deed behind it, and we never quote super built-up. If a listing looks cheap per foot, it should be because it is — not because someone changed the denominator.

How to protect yourself

• Always ask: is this price on carpet or super built-up?
• Ask for the registered ₹/ft² of recent deals in the same building.
• Compare only like for like — carpet to carpet.
• Get the all-in cost, including stamp duty and brokerage, in writing.

Carpet ₹/ft² = registered consideration ÷ carpet area (IGR Index-II). We never quote super built-up.