Five turrets rise above an underground tank, rectangular in plan. The four small ones, at the four vertices, ensure the ventilation of the tank. For the larger one, supported on one of its sides, you have access to the machinery and its interior. Its situation within the pass, on a hill, allows the whole to be observed from different points of view, almost always far away - that is why we are interested in artificially increasing all the apparent elements of the set. This double objective is taken care of by the enveloping porticos, the formal role of which has been maximised by resolutely disassociating them from any resistant work, while at the same time accentuating their structural appearance.

The building is located in the northern part of Plaça de la Constitució, on the axis with the Dr. Moragues Avenue and slightly moved to one side to suggest and connect the passage towards Estoril and Nàpols Streets, on the other side of the future 'Interpolar'. The building, structured in three staggered floors, from the basement to the first floor, creates a large overhang in the connection area between the two neighbourhoods. A large part of the library is planned to be underground to take advantage of the maximum surface area of the square and to minimise the volumetric impact on the current constructions in the area. This basement is ventilated and lit by a patio with fully glazed walls and covered with a pergola with adjustable slats to filter the light. The patio also illuminates part of the floor, which has already undergone displacement, giving access to the square. This lighting mechanism culminates on the second floor. The courtyard of light creates a fissure along the entire building; on the other hand, the building is very closed in its perimeter façades. The entire ground floor of the library is organised in such a way that it is accessible and permeable to the circulation of users. At one end is the bar-cafeteria and the exhibition hall, connected to the library, which can be used independently of it. The main access is open towards the square and has the information and reference spaces, the general background area, music, image and computerised consultation spaces, which are also located on the ground floor. In the basement there is the rest of the general background area, support spaces, study space, multimedia space and storage room, tanks and installations. On the ground floor is the children's area and the internal work area. The children's area space is connected to the patio-garden with a covered porch. The structure is made of reinforced concrete bearing walls and pillars. The façade is made of granite.