Carpet Area vs Built-up Area vs Super Built-up Area: What You're Actually Paying For

This is consistently one of the most confusing terms for apartment buyers, mostly because builders have historically had an incentive to quote on the largest possible number. Post-RERA, the rules got clearer — but the confusion in everyday conversation hasn't fully gone away.

Carpet area — the space you actually use

Carpet area is the net usable floor area within the walls of your unit — literally, the area you could cover with a carpet. It excludes the thickness of the walls themselves, balconies (counted separately under RERA), and any common areas. This is the most honest measure of livable space, and it's what RERA now requires builders to disclose clearly.

Built-up area — carpet area plus your own walls

Built-up area adds the thickness of the walls (internal and external) enclosing your unit to the carpet area. It's typically around 10-15% more than carpet area, depending on wall thickness and unit design.

Super built-up area — your share of the building's common spaces too

Super built-up area (sometimes called 'saleable area') adds a proportionate share of common areas — lobbies, staircases, lifts, corridors, clubhouse, and other shared amenities — on top of built-up area. This is usually what the per-sq-ft rate you see advertised is actually calculated on, and it's typically 20-35% larger than the carpet area of the same unit.

Why the gap matters when comparing two projects

Two apartments advertised at the same super built-up area and the same rate per sq ft can have meaningfully different actual carpet area, depending on each project's 'loading' (the ratio of super built-up to carpet). Always ask for the carpet area figure specifically — RERA-registered projects are required to disclose it — and compare projects on carpet area, not just the headline super built-up number.

A quick way to compare

Divide the total price by the carpet area (not the super built-up area) to get a true per-sq-ft-of-usable-space cost. This single calculation often reorders which project actually looks like better value.