Carpet vs built-up vs super built-up
Builders quote one area and sell you another. Enter what you were told, see the real carpet area you can actually use — and the true price per usable square foot, the way RERA intends you to compare it.
Ask the builder, or estimate: 25–35% is typical for Indian apartments; 40%+ for amenity-heavy towers.
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You pay for 300 sq ft of common area (loading) you can't furnish. Space efficiency: 76.9%. Total consideration at the quoted rate: ₹1,30,00,000.
The Real Estate (Regulation and Development) Act, 2016 defines carpet area as the net usable floor area within the walls of an apartment — excluding the external walls, service shafts, balcony/verandah and open terrace, but including the area of the internal partition walls. Crucially, RERA requires developers to sell on carpet area, not on the inflated “super built-up” (saleable) figure builders long used. The super built-up figure may still appear in marketing — but your price, and your comparison between projects, should be anchored to carpet.
| Term | What it includes | Use it for |
|---|---|---|
| Carpet | Usable floor inside your walls (incl. internal partitions) | The RERA price basis + how much you can actually furnish |
| Built-up | Carpet + external walls + balcony (≈ 10–15% more) | Older agreements; a middle figure, rarely the price basis now |
| Super built-up | Built-up + your share of lobbies, stairs, lifts, amenities | Builder marketing; never a fair price basis under RERA |
- Ask for the carpet area in writing — the agreement and the RERA registration must state it.
- Re-quote every project at ₹ per carpet sq ft before comparing; a lower super-built-up rate can be the costlier flat.
- Check the loading factor — a 45% loading hides a lot of corridor; 25–30% is efficient.
- Confirm the RERA registration number and look the project up on your state RERA portal.
An estimate for comparison. Carpet, built-up and loading definitions can vary slightly by state and builder; always rely on the figures stated in your sale agreement and RERA registration.
Related Guides — Deep-dive reading
Carpet Area vs Built-Up vs Super Built-Up Area — What You Actually Pay For
The three numbers that describe the same flat — and the loading factor that decides how much usable space your rupees really buy.
Home Buying BasicsThe Truth About Cost Per Square Foot
Why a ₹/sqft interior quote is the most misleading number in Indian home costing — and how to convert it into a real BOQ
Cost & MoneyApartment Interior Planning in India — Society Rules, Typologies, Space-Saving & Costs
The Eight Differences from House Planning, Five Apartment Typologies, NOC Flowchart, Twelve Space-Saving Strategies & Four Cost Bands
Room PlanningRelated Tools — You may also find these useful
Carpet vs Built-up Area Calculator
From the advertised super built-up area and loading factor, see the RERA carpet area, built-up area, efficiency and the effective price per usable foot.
Property CalculatorPlot Buildability Report
How much can you build? FSI, ground coverage, setbacks and height → buildable footprint, built-up area, floors, parking and area statement, with a PDF.
Feasibility ToolPre-Possession Inspection Checklist
Inspect your flat before registration — 10 categories, 70+ checkpoints across legal, carpet area, structure, finishes, and deviations.
Homebuyer Checklist