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Carpet Area vs Built-Up Area vs Super Built-Up Area: What Every Buyer Must Know

Carpet Area vs Built-Up Area vs Super Built-Up Area: What Every Buyer Must Know

By Property.new Team•June 9, 2026•5 min read

Carpet Area vs Built-Up Area vs Super Built-Up Area: What Every Buyer Must Know

You are looking at a 2BHK. The developer says it is 1,200 square feet. It sounds like a decent size. You visit the sample flat and it feels much smaller than you expected. Something does not add up.

What you are experiencing is the difference between carpet area, built-up area, and super built-up area. It is one of the most misunderstood aspects of buying property in India, and it is also one of the most financially significant.

Understanding the difference is not a technicality. It directly affects how much space you get and how much you pay per square foot of usable space.

The Short Version

Before we go into detail, here is a simple way to understand the three terms:

  • The carpet area is where you can really lay a carpet.It is the usable area inside your flat.
  • Built-up area is the carpet area plus the walls and balcony. Slightly larger than carpet area.
  • Super built-up area is the built-up area plus your share of all common spaces in the building. This is the largest number and the one developers typically advertise.

You pay for the super built-up area. You live in the carpet area. The difference between them can be 25 to 40 percent of the total area, sometimes more.

Carpet Area: The Only Number That Actually Matters

Carpet area is the net usable floor space inside your flat, measured from wall to wall. It is literally the area where you can lay a carpet. It includes the bedroom, living room, kitchen, and bathrooms, but only the floor space you can actually walk on and use.

Under RERA, the official definition of carpet area excludes the area covered by external walls, areas under service shafts, exclusive balcony or verandah area, and exclusive open terrace area.

This is the most honest measure of what you are actually buying.

Under RERA, developers must mandatorily disclose the carpet area of every unit before sale. Pricing must be based on carpet area, not super built-up area. This is one of the most important buyer protections RERA introduced.

What carpet area includes:

  • Bedroom, living room, kitchen, dining area floor space
  • Bathroom and toilet floor space
  • Internal walls and partition walls within the flat
  • Internal staircases if the flat is a duplex

What carpet area does not include:

  • Balcony or verandah area
  • External walls of the flat
  • Open terrace area
  • Any common area outside the flat

Built-Up Area: Carpet Area Plus the Walls

Built-up area is the carpet area plus the thickness of the internal and external walls of your flat, plus the balcony area. It is always larger than carpet area because walls take up physical space even though you cannot use them.

On average, built-up area is 10 to 15 percent more than carpet area. So if your flat has a carpet area of 900 square feet, the built-up area is approximately 990 to 1,035 square feet.

Quick formula:

Built-Up Area = Carpet Area + Wall Thickness + Balcony Area

Example: A flat with 900 sq ft carpet area and 120 sq ft of walls and balcony has a built-up area of 1,020 sq ft.

Super Built-Up Area: What You Pay For

Super built-up area, also called saleable area, is the built-up area of your flat plus your proportionate share of all common spaces in the building. These common spaces include the lobby, corridors, lifts, staircase, clubhouse, gym, swimming pool, and any other shared amenities.

This added portion is called the loading factor.

Super built-up area is typically 25 to 40 percent more than carpet area.

Quick formula:

Super Built-Up Area = Built-Up Area + Proportionate Share of Common Areas

Example: A flat with 1,000 sq ft carpet area and a 30 percent loading factor has a super built-up area of 1,300 sq ft.

Pre-RERA, a developer could quote Rs 6,000 per sq ft on super built-up area. That sounds affordable. But the equivalent price on carpet area was Rs 8,400 per sq ft. RERA fixed this by mandating carpet area pricing, but some developers still show super built-up area in brochures alongside the RERA carpet area figure. Always anchor to carpet area.

A Real Example: What the Numbers Look Like

Let us say a developer is advertising a 2BHK at 1,350 square feet. Here is what that might actually mean:

Area Type

Square Feet

What it Means

Super Built-Up Area

1,350 sq ft

What developer advertises

Built-Up Area

1,080 sq ft

Flat + walls + balcony

Carpet Area

900 sq ft

Actual usable space

Now apply a price of Rs 7,500 per square foot on the super built-up area:

  • Total cost: Rs 1,350 x 7,500 = Rs 1.01 crore
  • Effective cost per carpet sq ft: Rs 1,01,25,000 divided by 900 = Rs 11,250 per sq ft

You thought you were paying Rs 7,500 per sq ft. The actual cost per sq ft of usable space is Rs 11,250. That is a 50 percent difference.

What RERA Says About Carpet Area

RERA introduced three key protections for buyers:

  • Mandatory disclosure: Developers must declare the carpet area of every unit in the RERA registration documents. You can verify this on your state RERA portal.
  • Pricing on carpet area: Developers must charge on the basis of carpet area. They cannot price properties on super built-up area only.
  • 3 percent variation limit: Under RERA, the actual carpet area at possession can vary by a maximum of 3 percent from what was declared at the time of booking. If the actual carpet area is less than what was promised, the developer must refund the excess amount paid, with interest.

Loading Factor: The Number to Always Ask For

The loading factor, or loading percentage, tells you how much of what you are paying for is common area that you share with your neighbours rather than your own usable flat.

A loading factor of 20 percent means that 20 percent of the price you pay is for common areas. A loading factor of 40 percent means you are paying for 40 percent extra area that you will never have exclusive use of.

Loading factors vary by project type:

  • Affordable housing projects: typically 15 to 20 percent loading
  • Mid-segment residential projects: typically 25 to 30 percent loading
  • Premium projects with extensive amenities: 30 to 40 percent loading or more

Before booking, ask for the exact loading factor and confirm it against RERA documents.

How to Compare Properties Correctly

Most buyers compare properties by advertised size and get misled.

But if Developer A has a 35 percent loading factor and Developer B has a 20 percent loading factor, the actual carpet areas are:

  • Developer A: 1,200 divided by 1.35 = approximately 889 sq ft carpet area
  • Developer B: 1,100 divided by 1.20 = approximately 917 sq ft carpet area

Developer B gives more usable space. Always compare on carpet area.

On property.new, all new launch listings are RERA-compliant. You can compare projects on carpet area before shortlisting.

Balcony Area: Where Does It Fit?

Balcony area is excluded from RERA carpet area but is separately disclosed in RERA registration documents. Under the current RERA rules, balcony area is counted at 100 percent of its actual area in RERA registrations, not at 50 percent as some developers used to claim.

Ask for carpet area excluding balcony and balcony area separately.

Conclusion: Always Start With Carpet Area

Of the three area measurements you will encounter when buying property in India, carpet area is the only one that tells you the truth about how much space you are actually getting.

Super built-up area reflects real costs, but always convert to carpet area before comparing price per sq ft.

property.new follows RERA-compliant listings across all new launch projects. When you browse, you will see confirmed RERA data.

The next time a developer tells you that a flat is 1,400 square feet, the first question to ask is: is that carpet area or super built-up? Those three words can represent a difference of hundreds of square feet and several lakhs of rupees.

Always ask for carpet area. Always verify it on the state RERA portal. And always calculate the effective price per carpet square foot before deciding if a property is worth its price.

Frequently Asked Questions

Q1. Which area measurement should I use when comparing two properties?

Always compare on carpet area. Super built-up area varies significantly across projects depending on the loading factor. Two flats that both advertise 1,200 square feet of super built-up area may have very different actual carpet areas. Carpet area gives you a fair, apples-to-apples comparison.

Q2. Is super built-up area mentioned in the sale agreement?

Under RERA, the sale agreement must mention the carpet area as the primary measurement. Super built-up area may also be mentioned but pricing must be based on carpet area. If a developer asks you to sign an agreement that prices the property on super built-up area only, that is a RERA violation.

Q3. What happens if the carpet area at possession is smaller than what was promised?

Under RERA Section 14, if the actual carpet area is less than what was agreed in the sale agreement, the developer must refund the excess amount paid for the shortfall, along with interest. The maximum permitted variation is 3 percent. Anything beyond that entitles you to a proportionate refund.

Q4. Does loading factor affect property tax and maintenance charges?

Property tax is typically calculated on the built-up area or carpet area depending on the city's local authority rules. Maintenance charges are usually calculated on the super built-up area since they cover the common amenities you share with other residents. Always ask the developer for the maintenance charge calculation basis before booking.

Q5. How do I find the carpet area of a property on the RERA portal?

Go to your state RERA portal and search by the project name or registration number. Each registered project lists the approved unit types with carpet area, balcony area, and other details. This is the legally declared carpet area you can hold the developer accountable to.

Published on property.new | India's First Platform for New Launch Homes