Madrid Stadium, completed and assigned to athletics in 1992, consists of a single grandstand of large seating capacity. In 2004, the City Council of Madrid undertook the development of an expansion project for this site to convert this into a football stadium with a capacity for 70 000 spectators. The design of the stadium also took into account the possibility of transforming the structure and facilities of the building for use as an athletics stadium should the city of Madrid host Olympic Games in the future.The foundation is made up of castin-place executed piles, with up to 1500 mm diameter and 40 m length. Integrity tests were done. Micropiles were necessary to reinforce the current stadium’s foundation to bear the loads arising from the new structure.The structure of the new stadium is mainly composed of radially placed rigid frame structures that together with the existing grandstand resulted in a completely closed stadium. Precast concrete steppings are placed over these rigid frame structures. Beneath these elements there are reinforced-concrete or post-tensioned slabs that define the building’s floors. The entire structure is surrounded by perimeter walls that constitute the building enclosure.Finally, the stadium is covered with a roof structure executed with a heavy lifting system, consisting of pairs of radial pre-stressed cables connecting the outer compression ring with the inner tension ring and covering the stands with pre-stressed textile membranes.