It is the structural base on which the staircase rests to ensure its stability and safety. this foundation includes a series of elements such as footings; concrete slabs or blocks; which distribute the weight of the staircase and additional loads to the ground. the detail generally specifies the dimensions; the arrangement of the reinforcing steel; the excavation depth; and the materials used; ensuring that the staircase complies with construction regulations and adequately supports the anticipated loads.