Built-up area is the flat itself including its walls; super built-up area adds your proportionate share of common areas such as the lobby, lifts, staircases and corridors. Super built-up is a pricing figure, not a measurement of your home.
Price quotes and maintenance bills in many projects
Can be checked by measuring
Roughly, from the flat
No; depends on the builder's allocation of common areas
Gap to carpet area
Wall thickness and balcony
Called loading; set by the builder
When Built-up area matters
Use built-up area to understand the physical footprint of the flat, for example when reading an approved plan.
When Super built-up area matters
Super built-up area matters for working out what a quoted rate really buys and for maintenance charges billed per square foot of it.
In more detail
The difference between super built-up and carpet area is the loading. Loading figures commonly cited for city apartment projects are around 25% to 35% of the super built-up area, but the actual figure varies by project, so ask the seller for it.
Divide the total price by the carpet area to compare two homes fairly. The full guide works through an example.