What is Loading Factor?
Loading Factor — Loading factor is the percentage by which a property’s super built-up (saleable) area exceeds its carpet (usable) area — the share of walls, balcony and common spaces (lobbies, lifts, corridors, clubhouse) you pay for but cannot use exclusively. For example, a 1,000 sq ft super built-up flat with 750 sq ft carpet has a 33% loading factor. Kolkata high-rises typically run 25–35%; lower loading means more usable space per rupee.
How to Calculate Loading Factor
The formula: Loading factor = (Super built-up area ÷ carpet area − 1) × 100.
- 1,000 sq ft super built-up with 750 sq ft carpet → (1000/750 − 1) × 100 = 33% loading
- Equivalent form: carpet efficiency = carpet ÷ super built-up × 100 (750/1000 = 75%)
- Loading factor + carpet efficiency always describe the same ratio from opposite ends
Typical Loading in Kolkata
Loading has grown as clubhouses, double-height lobbies and amenity decks became standard:
- Older (pre-2000) low-rise buildings: 15–22% loading
- Standard 2000s–2010s high-rises: 25–30% loading
- Premium 2020s towers with large amenity decks: 30–35% loading
- Above ~40% loading, question the value — you are buying a lot of shared space
Why Loading Changes Your Effective PSF
Loading converts a headline price into what you actually occupy. Take two New Town listings at the same ₹8,000/sq ft super built-up PSF: one with 70% carpet efficiency gives you an effective carpet PSF of ₹11,429; one with 80% efficiency gives ₹10,000 — a 14% difference in value for the identical headline rate. RERA’s carpet-area pricing rule exists precisely to make this visible.
How to Use Loading When Shortlisting
Ask every developer for both numbers — carpet area and super built-up area per configuration — and compute the loading yourself before comparing prices. On RealtyIQ, project pages list the carpet area range for every configuration, so the loading can be checked against the quoted saleable area in the price sheet.
Frequently asked questions
What is a good loading factor?
In Kolkata, 25–30% is normal for modern high-rises; below 25% is efficient and typically found in lower-rise or older buildings; above 35% means a large share of your payment goes to common areas. Always weigh loading against amenities — 32% loading with a real clubhouse may beat 26% without one.
Is balcony included in the loading factor?
Yes. The gap between super built-up and carpet area includes your balcony and verandah (which RERA excludes from carpet area) plus your share of common areas. Balconies are often sold at 50% of the per-sq-ft rate, which is part of why loading math differs slightly between developers.
How is loading factor different from carpet area?
Carpet area is the usable space inside your walls; loading factor is the percentage ADDED on top of it to arrive at the saleable (super built-up) area. A 750 sq ft carpet with 33% loading is sold as ~1,000 sq ft super built-up.
Does a lower loading factor mean a cheaper flat?
Not automatically — it means more of every rupee buys usable space. Compare all-in price per carpet-area sq ft (price ÷ carpet area) across shortlisted projects; that single number already prices in loading, carpet efficiency and any floor-rise charges.
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