The wall and roof are supported on the strength of the foundation. Walls are basically meant to separate rooms. Bricks or granite can be used for walls. Cement and sand can be saved if you choose these options. The laterite stone should have a thickness of 22 cm. If bricks are used, the ground floor walls should have a thickness of 30 cm and the upper floor walls should have a thickness of 20 cm. For laterite, partitioning walls should have a 15 cm thickness and bricks should have a 10 cm thickness.
For bathrooms and storerooms, the height should be 210-220 cm. Not only will this be stronger, the cost will be less too. A 4½ in wall with 9 in pillar should be build with cement in the ratio 1:6. This will reduce cost further. If the 9 inch walls are hollow, you can save 30% brick and cement. Brick can be used to build up to a floor. Reducing the height of the wall will also reduce the cost. Cement and sand should be taken in the proper proportion here.