Before RERA, "carpet area" was used loosely and usually meant the floor between the walls of each room, leaving out internal walls. RERA carpet area is the defined figure: net usable floor area including internal partition walls, excluding external walls, shafts, exclusive balconies and exclusive open terraces.
Side by side
Factor
Carpet area
RERA carpet area
Source
Market usage; varied by seller
Section 2(k) of the RERA Act, 2016
Internal partition walls
Often excluded
Included
External walls
Excluded
Excluded
Service shafts
Varied
Excluded
Exclusive balcony or verandah
Sometimes added
Excluded; stated separately
Exclusive open terrace
Sometimes added
Excluded; stated separately
Binding in a sale
Only if the agreement defines it
Must be stated in a RERA project's agreement for sale
When Carpet area matters
Old resale documents and pre-RERA brochures may give a carpet figure; read how it was measured before comparing it with a RERA figure.
When RERA carpet area matters
For any project registered under RERA, the RERA carpet area is the figure you pay for and the one to check at possession.
In more detail
Because RERA carpet area includes internal partition walls, it can be slightly larger than a room-by-room carpet measurement of the same flat. The two are not interchangeable, and neither includes the balcony.
Many state RERA rules also ask builders to state balcony, verandah and terrace areas separately. Read the schedule attached to the agreement for sale: it should list each.
For resale homes outside RERA, there is no obligation to use this definition. Ask the seller which definition a figure follows, or measure the rooms.