Building a 30x40 house in Bangalore can be a costly affair. The cost of construction depends on the type of materials used, the quality of construction, the labor costs, and the location of the house. The cost of construction for a 30x40 house in Bangalore can range from Rs. 1,500 to Rs. 2,500 per square feet. This means that the total cost of construction for a 30x40 house in Bangalore can range from Rs. 45 lakhs to Rs. 75 lakhs.