In my training as public health officer, building and construction was integral module. Herewith then, is a bit knowledge on buildings stability.
There are two types of settlement; equal [or uniform] settlement and unequal settlement. Equal settlement is the process by which a building settles on the foundation uniformly and achieves maximum stability or balance. Equal settlement may occur with uniform or minimal cracks in the structure. With unequal settlement, a building displaces subsoil in an uniform manner, thus destabilizing the building and creating differential resting positions. The effect of unequal settlement may be evidenced by cracks on walls, distortion of door and window openings, walls thrown out of vertical and collapse of buildings.
To remedy this. It is necessary for both the designer and the builder to know what is below the ground where the construction is going to take place since the building has to be supported by it.The nature, strength, bearing capacity and likely behavior of of such soils have to be ascertained alongside the nature and load excertion of the building materials to be used. The load includes that exerted by wind-that why Hilton hotel and Kenyatta International Conference Center [KICC] are cylindrical.
This calls then for site investigation by personalities involved in building industry.