The structure of the 12 de Octubre hospital expansion is made up of 135,000 m2 slabs on 12 levels, perimeter in situ walls and in elevator and stair cores, as well as circular and rectangular pillars. Table systems, a modular aluminum system and a traditional mechano system are combined for the slab formwork. The geometry of the buildings is up to Level 4, a rectangular plan, from Level 5 the building is reduced into two “V” -shaped buildings and one “I” -shaped building, all of which connect to a common area. where all the elevator and stair cores are located.