Carpet area, built-up area and super built-up area are three different ways of measuring a flat. Carpet area refers to the net usable floor area of an apartment under RERA, while built-up area generally includes walls and certain private areas, and super built-up area may also include a proportionate share of common areas.
Understanding the difference between these three measurements helps homebuyers compare apartment sizes, property prices and overall value more accurately.
What Is RERA Carpet Area?
RERA carpet area is the carpet area defined under the Real Estate (Regulation and Development) Act, 2016. It refers to the net usable floor area of an apartment, excluding external walls, service shafts, exclusive balcony or verandah areas, and exclusive terraces, while including the area covered by internal partition walls. For homebuyers, this is an important area figure to check in RERA project records and sale documents.
Included in Carpet Area | Excluded from Carpet Area |
Net usable floor area | External walls |
Internal partition walls | Service shafts |
Rooms, kitchen and bathrooms | Exclusive balcony/verandah |
— | Private terrace |
How Is Carpet Area Calculated?
Carpet area is calculated based on the net usable floor area of the apartment, while excluding external walls, service shafts, exclusive balconies or verandahs. Internal partition walls are included under the RERA definition.
For example, if an apartment has 900 sq ft of usable floor area and 50 sq ft covered by internal partition walls, the RERA carpet area would be 950 sq ft, assuming there are no excluded areas within that measurement.
Built-Up Area
Carpet area plus the area occupied by your flat's walls and, where applicable, an exclusive balcony or similar private area. The exact relationship between carpet area and built-up area varies by project design, so there is no fixed percentage that applies to every apartment.
Built-Up Area ≈ Carpet Area + Wall Area + Applicable Private Balcony/Other Areas
Super Built-Up Area (often referred to as Saleable Area)
Built-up area plus your proportional share of common areas - lobbies, staircases, lift shafts, corridors, and shared amenities. The resulting figure depends on how common areas are apportioned in the project.
Super Built-Up Area = Built-Up Area + Proportional Share of Common Areas
If a flat has a built-up area of 1,100 sq ft and its proportionate share of common areas is 300 sq ft, the super built-up area would be 1,400 sq ft.
Area Type | What It Includes | Common Areas | Why It Matters |
Carpet Area | Net usable floor area and internal partition walls | NO | Best figure for comparing the actual apartment size |
Built-Up Area | Carpet area plus walls and applicable private areas | No | Shows the apartment's overall constructed area |
Super Built-Up Area | Built-up area plus proportionate common areas | Yes | Often used as the saleable area figure |
What RERA Actually Changed - And Why It Matters to You
Before RERA's provisions came into effect, buyers often encountered different area measurements in property marketing, making it difficult to understand how much of the quoted area was actually usable. A buyer could pay for "1,500 sq ft" without ever being told that only 1,000 sq ft of it was space they could actually use.
RERA changed the rulebook in a few concrete ways:
Carpet area is the key area figure buyers should use when comparing apartments under RERA. RERA requires the carpet area of the apartment to be disclosed in the project registration and related sale documentation, giving buyers a clearer basis for comparing properties than relying only on built-up or super built-up figures.
Buyers should compare apartment prices using the RERA-disclosed carpet area rather than relying only on a super built-up or saleable-area figure. Other charges, such as parking or certain amenities, should also be checked separately in the agreement for sale.
What happens if the final carpet area differs from what was agreed? If the final carpet area is different from the area originally agreed or disclosed, the buyer's rights and any applicable refund or price adjustment depend on the applicable RERA provisions and the agreement for sale.
For RERA-registered projects, disclosed carpet-area information gives buyers a more consistent basis for comparing apartments. This makes it easier to compare properties beyond the larger headline numbers used in marketing.
In short, RERA makes carpet-area disclosure an important part of understanding what you are buying. Buyers should check the RERA-disclosed carpet area and compare it with the total property price and other applicable charges.
The Number That Actually Matters: Loading Factor
"Loading" refers to the difference between the super built-up area and carpet area, expressed as a percentage of the carpet area.
Loading Factor = (Super Built-Up Area − Carpet Area) ÷ Carpet Area × 100
A worked example: If a flat has a carpet area of 800 sq ft and a super built-up area of 1,200 sq ft:
Loading = (1,200 − 800) ÷ 800 × 100 = 50%
This means the super built-up area is 50% higher than the carpet area. There is no single standard loading factor across all projects. It can vary depending on the project's design, common facilities and how common areas are apportioned.
Why Carpet Area Matters When Comparing Property Prices?
Suppose a flat has a carpet area of 1,000 sq ft and a super built-up area of 1,400 sq ft, with a quoted property price of ₹70 lakh. The headline area may make the apartment appear larger, but the carpet area tells you how much enclosed floor space you are actually getting. Looking at the price in relation to carpet area can therefore make comparisons between different projects more meaningful.
For example, when comparing 2 BHK flats in Ahmedabad, buyers should compare the RERA carpet area along with the total price rather than relying only on the advertised saleable area.
Which Area Should a Homebuyer Compare?
When comparing apartments, start with the RERA-disclosed carpet area because it provides a consistent basis for understanding the size of the apartment itself. Then compare the total property price, super built-up or saleable area, loading factor and additional charges such as parking and other applicable costs. A larger super built-up area does not necessarily mean more usable space inside the apartment.
How to Verify Any Project's Real Carpet Area Yourself
You don't have to rely only on a brochure. For RERA-registered projects, carpet-area details can be checked through the relevant RERA project records:
1. Go to your state's official RERA portal - for Gujarat, that's gujrera.gujarat.gov.in
2. Search the project by name or RERA registration number
3. Check the registered carpet area against what the brochure or sales team quoted you
4. If the numbers don't match, ask the developer or sales team to explain the difference and verify the applicable project documents.
What Ahmedabad Home Buyers Should Check
When comparing flats in Ahmedabad, don't judge the size of a property from the largest area figure shown in a brochure. Check the RERA-disclosed carpet area first, then understand the super built-up or saleable area and the resulting loading factor. Buyers should also check how balconies, terraces, parking and other additional charges are treated in the agreement for sale.
Before making a decision, check:
RERA-disclosed carpet area
Super built-up or saleable area quoted by the developer
Loading factor
Balcony or terrace area
Parking and other additional charges
Agreement-for-sale details
When comparing flats in Ahmedabad, don't judge value from the largest area figure in the brochure. Compare the carpet area, total price and applicable additional charges across similar projects.
Frequently Asked Questions
What is the difference between carpet area and built-up area? Carpet area is the net usable floor area of an apartment under the RERA definition, including the area covered by internal partition walls. Built-up area generally adds the area occupied by walls and, where applicable, an exclusive balcony or similar private area.
Is it illegal for a builder to quote super built-up area? Quoting a super built-up or saleable-area figure for context is not the same as replacing the RERA-disclosed carpet area. Buyers should check the RERA-disclosed carpet area when comparing apartment prices and review how the total price and additional charges are described in the agreement for sale.
What is a "good" loading factor? There's no universal good number - it depends on the project type and amenities on offer. What matters more than the number in isolation is knowing it upfront and being able to compare it against similar projects in the same locality and segment.
What happens if the actual carpet area delivered is less than what was promised? If the final carpet area differs from what was originally agreed or disclosed, the buyer may have rights to a refund or price adjustment under applicable RERA provisions and the agreement for sale.
How do I calculate loading factor myself? Loading Factor = (Super Built-Up Area − Carpet Area) ÷ Carpet Area × 100. Ask the builder or sales team directly for both numbers so you can compare the property on the same basis.