When purchasing property in India, you’ll encounter confusing terms like carpet area, built-up area, super built-up area, and loading factor – each affecting the final price you pay. Understanding these measurements is critical because as of Q1 2025, homebuyers in India’s top cities receive only 60% of their purchased space as actual liveable area and the remaining 40% comprises common spaces (ANAROCK Research). This comprehensive guide demystifies Indian real estate terminology to help you make informed buying decisions.
1. Carpet Area (Net Usable Area)
RERA Official Definition
According to the Real Estate (Regulation and Development) Act, 2016, carpet area means:
“The net usable floor area of an apartment, excluding external walls, service shafts, exclusive balconies/verandahs, and open terraces, but including the area covered by internal partition walls.”
What’s Included:
Bedrooms, living room, kitchen, bathrooms
Internal partition wall thickness (5% additional space vs. general carpet area)
All habitable enclosed spaces
What’s Excluded:
External/load-bearing walls
Balconies and verandahs (even if enclosed)
Terraces and open spaces
Service shafts (lifts, plumbing ducts)
Formula:
RERA Carpet Area = Net usable floor space + Internal partition walls
RERA Carpet Area = General Carpet Area × 1.05 (5% additional for walls)
Example:
- General carpet area: 1,000 sq ft
- RERA carpet area: 1,050 sq ft (1,000 × 1.05)
Why It Matters: RERA mandates that property pricing must be based on carpet area—the actual living space—not inflated measurements. This is the only measurement you legally pay for.
Source: RERA Act Section 2(k)
2. Built-Up Area (Plinth Area)
Definition
Built-up area is the total covered area measured at floor level, including carpet area plus structural elements.
What’s Included:
Carpet area
Thickness of external and internal walls
Balconies (covered and uncovered)
Utility areas like exclusive corridors
What’s Excluded:
Common areas (lobbies, lifts shared by all)
Open terraces without walls
Calculation Formula:
Built-Up Area = Carpet Area + Wall Thickness + Balcony + Utility Areas
Typical Size = Carpet Area × 1.10 to 1.20 (10-20% more)
Example:
- RERA carpet area: 1,050 sq ft
- Built-up area: 1,155–1,260 sq ft (10-20% more)
Usage: Builders use built-up area for construction calculations and property tax assessments.
Source: Housing.com Built-Up Area Guide
3. Super Built-Up Area (Saleable Area)
Definition
Super built-up area is the total saleable area: your built-up area plus proportionate share of all common areas in the building/complex.
What’s Included:
Built-up area
Proportionate common areas:
- Lobbies, corridors, staircases
- Lifts and lift shafts
- Clubhouses, gyms, swimming pools
- Parking areas (if shared)
- Community facilities
Calculation Formula:
Super Built-Up Area = Built-Up Area + Proportionate Common Area
OR
Super Built-Up Area = Carpet Area × (1 + Loading Factor)
Example:
- Carpet area: 1,050 sq ft
- Loading factor: 40% (India average Q1 2025)
- Super built-up area: 1,470 sq ft (1,050 × 1.40)
Critical Note: Before RERA, developers priced properties based on super built-up area, inflating costs. RERA now mandates carpet area pricing, bringing transparency.
Source: RERA Carpet Area Calculation
4. Loading Factor: The Hidden Cost
Definition
The loading factor is the percentage difference between carpet area and super built-up area, representing the proportion of common areas added to your unit’s cost.
Formula:
Loading Factor = [(Super Built-Up Area – Carpet Area) / Carpet Area] × 100
City-Wise Loading Factors (Q1 2025):
| City | Loading Factor | 2019 Baseline |
| Mumbai (MMR) | 43% | 33% |
| Delhi-NCR | 41% | 31% |
| Bengaluru | 41% | 29% |
| Pune | 40% | 32% |
| Kolkata | 39% | 30% |
| Hyderabad | 38% | 27% |
| Chennai | 36% | 28% |
| India Average | 40% | 31% |
Alarming Trend: Loading factors have increased 29% in 6 years (2019-2025), meaning homebuyers now get only 60% usable space for their money.
Example Calculation:
- Super built-up: 1,500 sq ft
- Carpet: 1,000 sq ft
- Loading factor: 50% [(1,500-1,000)/1,000 × 100]
Financial Impact: Higher loading means paying more for shared spaces. A property with 50% loading charges you ₹5 lakh per 100 sq ft, but only delivers 67 sq ft of living space.
Source: ANAROCK Research Q1 2025
5. Common Area (Shared Facilities)
RERA Definition (Section 2(n))
Common areas are indivisible shared spaces within a complex belonging to all residents collectively.
What’s Included:
Land: Entire project land (not just buildings)
Vertical Elements: Staircases, lifts, lobbies, fire escapes
Horizontal Spaces: Common terraces, basements, parks, play areas
Service Areas: Security rooms, pump rooms, electrical installations
Amenities: Clubhouses, gyms, swimming pools, commercial shops
Key Point: No individual owner can claim ownership or partition of common areas.
Proportionate Share Calculation:
Your Share = (Your Built-Up Area / Total Built-Up Area) × Total Common Area
Example:
- Your built-up: 1,200 sq ft
- Total project built-up: 100,000 sq ft
- Total common area: 20,000 sq ft
- Your proportionate share: 240 sq ft (1,200/100,000 × 20,000)
Source: RERA Section 2(n) Common Areas
6. Amenity Area
Definition: A subset of common areas specifically designed for recreational/social use.
Includes: Clubhouse, swimming pool, gym, play areas, gardens, meeting rooms.
Differs from Common Area: Utility spaces (lift shafts, staircases, service corridors) are common areas but not amenities.
7. Dry Balcony
Definition: An enclosed or semi-enclosed outdoor space for functional activities (laundry, storage, utility) not relaxation.
Characteristics:
- Protected from weather but open-air
- Used for practical tasks, not living
- Not included in RERA carpet area
RERA Treatment: Balcony area must be listed separately in sale documents, even if covered.
Source: NoBroker Dry Balcony Guide
8. Covered Area
Definition: Only the portion physically covered by a roof—all interior spaces under a roof.
Includes: Rooms, corridors, bathrooms, kitchens
Excludes: Open balconies, terraces
Difference from Built-Up: Built-up includes balconies; covered area doesn’t.
9. Plinth Area (Built-Up Area)
Definition (Indian Standard IS 3861-2002): “The constructed covered area calculated at floor level.”
Usage: Property valuation, municipal tax calculations, construction cost estimation.
Typical Size: 10-20% more than carpet area.
Source: Housing.com Plinth Area
RERA Mandatory Disclosures (2025 Rules)
Key Provisions:
- Carpet Area-Based Pricing: All sale agreements must price based on RERA carpet area, not super built-up.
- Separate Disclosure Requirement: Builders must list three distinct areas:
- RERA Carpet Area
- Exclusive Balcony/Verandah Area (listed separately)
- Exclusive Open Terrace Area
- Balconies Excluded: Balconies are explicitly excluded from carpet area, regardless of whether open/enclosed.
- Area Deviation Protection: If the final area is lower than promised, developers must refund/adjust prices within 45 days. Increases capped at 3% of originally promised carpet area.
- Standardised Definition: Uniform carpet area definition across all states.
RERA Impact: Eliminated malpractices where developers inflated prices using super built-up areas.
Source: RERA Act 2016 Mandatory Disclosures
Balconies: A Common Confusion
RERA Rule: Balconies Are NOT Carpet Area
Per RERA, balconies are explicitly excluded from carpet area, regardless of whether:
- Open or enclosed with grills
- Covered or uncovered
- Shared or exclusive
Mandatory Disclosure: Balcony area must be listed separately as “Exclusive Balcony/Verandah Area.”
Example:
- Flat A: 800 sq ft carpet + 150 sq ft balcony = 950 sq ft total
- Flat B: 800 sq ft carpet + 50 sq ft balcony = 850 sq ft total
Both have the same carpet area, but Flat A offers 100 sq ft more total space.
Source: RERA Balcony Exclusion Rules
Practical Comparison Table
| Term | Includes | Excludes | % More Than Carpet |
| Carpet Area | Usable rooms + internal walls | External walls, balconies, common areas | Baseline (100%) |
| Built-Up Area | Carpet + external walls + balconies | Common areas | +10-20% |
| Super Built-Up | Built-up + proportionate common areas | Nothing (most comprehensive) | +25-40% |
| Common Area | Shared spaces (lift, lobby, pool) | Individual unit space | Calculated separately |
| Covered Area | All roofed spaces | Open balconies, terraces | Similar to carpet |
Essential Tips for Homebuyers
1. Always Request RERA Carpet Area: Specifically ask for RERA carpet area, not super built-up.
2. Calculate Real Cost per Sq Ft:
Real Cost = Total Price / RERA Carpet Area
Compare properties using this, not super built-up pricing.
3. Check the Loading Factor: Ask: “What’s your loading percentage?” Lower is better (more usable space).
4. Verify Separate Disclosures: Ensure sale agreements list:
- RERA carpet area
- Balcony area (separately)
- Terrace area (separately)
5. Compare Intelligently: Two flats with the same super built-up can have vastly different carpet areas depending on building design.
6. Verify RERA Registration: Confirm project is RERA-registered at rera.tn.gov.in (Tamil Nadu) or your state RERA portal.
7. Understand the 60-40 Reality: In 2025, expect only 60% usable space (carpet area) from your total purchase (super built-up).
Cost of Confusion
A property at ₹5,000 per sq ft based on super built-up area (1,500 sq ft = ₹75 lakhs) might actually cost ₹7,500 per sq ft when calculated on true carpet area (1,000 sq ft = ₹75 lakhs). That’s a 50% hidden price increase due to loading.
By understanding RERA terminology and insisting on carpet area transparency, you can negotiate better deals, compare properties fairly, and avoid paying for inflated measurements.
Always demand RERA compliance and transparent carpet area disclosure. The post-RERA era has brought standardization – use this framework to your advantage. B&B Properties with its heritage of over thirty years ensures that all the compliances have been met and approvals taken to give you a hassle free ownership
Frequently Asked Questions
What is the difference between carpet area and RERA carpet area?
General carpet area excludes internal partition wall thickness. RERA carpet area includes internal partition walls, making it 5% larger. Formula: RERA Carpet Area = General Carpet Area × 1.05. RERA carpet area is the official standard for all property transactions in India.
Are balconies included in the carpet area as per RERA?
No. As per RERA Act 2016, balconies/verandahs/open terraces are explicitly excluded from carpet area, regardless of whether they’re open, enclosed, covered, or exclusive. Balcony area must be disclosed separately in all sale agreements.
What is the average loading factor in Indian cities in 2025?
The India average loading factor is 40% (Q1 2025), up from 31% in 2019. City-wise: Mumbai 43%, Delhi-NCR 41%, Bengaluru 41%, Pune 40%, Kolkata 39%, Hyderabad 38%, Chennai 36%. This means homebuyers get only 60% usable living space for their money.
How do I calculate the real cost per square foot of a property?
Divide the total property price by RERA carpet area, not super built-up area. Example: ₹75 lakh property with 1,000 sq ft carpet area = ₹7,500/sq ft real cost (not ₹5,000/sq ft if calculated on 1,500 sq ft super built-up).
What is the typical difference between carpet area and super built-up area?
Super built-up area is typically 25-40% more than carpet area in India. In luxury developments with extensive amenities, it can reach 50-60% more. This difference is the “loading factor” – your proportionate share of common areas.
General carpet area excludes internal partition wall thickness. RERA carpet area includes internal partition walls, making it 5% larger. Formula: RERA Carpet Area = General Carpet Area × 1.05. RERA carpet area is the official standard for all property transactions in India.
No. As per RERA Act 2016, balconies/verandahs/open terraces are explicitly excluded from carpet area, regardless of whether they’re open, enclosed, covered, or exclusive. Balcony area must be disclosed separately in all sale agreements.
The India average loading factor is 40% (Q1 2025), up from 31% in 2019. City-wise: Mumbai 43%, Delhi-NCR 41%, Bengaluru 41%, Pune 40%, Kolkata 39%, Hyderabad 38%, Chennai 36%. This means homebuyers get only 60% usable living space for their money.
Divide the total property price by RERA carpet area, not super built-up area. Example: ₹75 lakh property with 1,000 sq ft carpet area = ₹7,500/sq ft real cost (not ₹5,000/sq ft if calculated on 1,500 sq ft super built-up).
Super built-up area is typically 25-40% more than carpet area in India. In luxury developments with extensive amenities, it can reach 50-60% more. This difference is the “loading factor” – your proportionate share of common areas.
