[EN] The aim of the project is the design of a sports center pavilion in a existing real place, considering different options from a study of both the disposition and the structural system to be executed. Once evaluated pros and cons on the structural ideal system proceeds to the design and ckecking of the elements and the construction process to follow. The program used for its calculation is CYPE 3D. 3 solutions are proposed by the same structural system but changing the distribution in plant, looking for an ideal solution in terms of accessibility and safety of utilization of the pavilion, accesses to the parking, integration with the environment and the revitalization of the zone. In the report a work plan with a Gantt graph is included to show graphically the whole constructive process. The deadline for the development of the work is 7 months and the budget is € million. The project follows the requirements exposed in the CTE, besides specific regulation for buildings of public concurrence. The dimensions in plant of the plot (38 x 60 m) are decided for the minimum dimensions of the indoor pitch type 4 according to the Regulation of Sports Facilities and Recreation (NIDE), of 44 x32 m, leaving a space in wings and in the frontal of 6 and 12 meters of width respectively, to fulfill the minimal services established by the norm. In addition, there are two stairs to go up to the level one in the one that is the gym, offices, a massage room and changing rooms. In level 0 it has 3 changing rooms, the bar, an installation room, the rubbish room, the sports store, cleaning store, room for conservation, toilets and changing rooms for referees and trainers. The pavilion is composed by a framed structure of structural steel, with dimensions in plan of 38 x 60 m, in which a total of 9 interior porticos and 2 exterior porticoes follow each other. The distance between porticos is 6 meters, and it has a free height of 10 meters to the roof. The front and side porticos have intermediate pillars so that they can support the perimeter enclosure. For the choice of the structural system, in buildings with large separations between pillars as the project object is always a decisive aspect the weight of the structure, especially when the overload is reduced, as is the case of covers. Starting at 20 meters, the prefabricated concrete and steel construction systems tend to be more competitive, and for values of 30 meters or more, steel is the most advantageous solution. That is why the pavilion is designed of steel. As for the foundation of the structure, it has been designed with square surface footings braced by tie beams, considering the admissible calculation tension of 200 kPa, provided as starting data.