Why the builder has calculated the Super Build-up Area as 1.6?

Hi Vinod,
This is the trick used by builders/developers, when they say you can find carpet area by applying loading factor on the saleable area.
Suppose saleable Area= 1200 sq ft
Loading Factor= 25% (or 1.25)

Wrong Method (favours seller)
Carpet Area= 1200 x (100-25)% = 1200 x 75% = 900 sq ft
If you apply 1.25 or 25% loading, saleable area should be 900 sq ft + 900 x 25% = 1125 sq ft
As you can see under this method builder is charging you for 1200 - 1125 = 75 sq-ft more

Right Method (favours buyer)=
Find carpet area first by measuring actual dimensions, and then apply loading factor
Saleable area = 900 sq ft + 900 x 25% = 1125 sq-ft