Foundation st for 600 sq ft house:- In india, by using thumb rule, 600 sq ft house of 20 × 30 of Plot area, for normal residential building, Foundation st will be 20% to 25% of total st of one storey building upto plinth, total st of ground floor building will be = 1500× 600 = Rs 9 lakh, 20% of 9 lakh = 1.8 lakh or 25% of 9 lakh = 2.25