If one needs to know the 30×40 Duplex house construction in Bangalore on a 30×40 site then the built-up area comes in between 1700 sq ft to 1800 sq ft. ... ItemQuantityPrice Material127.05 cubic ft @ ₹ 235 per cubic ft₹ 29,857 Labour127.05 cubic ft @₹ 30 per cubic ft₹ 3,812 Total Price₹33,669 Feb 1, 2018