Dear D Ramachandran
The design of a building is done with the consideration of following points.
1. Bearing capicity of soils.
2. Design of fondation in respect of load to be bear by each member with respect to bearing capicity.
3. Walls and RCC columns are tha design keeping in view of load and safety against earth quack etc.
4.Similarelly lintels, beams and slab are designed.