The San Fernando de Henares Swimming Center completes a municipal sports facility composed of different constructions meshed by the passage of time. The complex, set outside of the urban center, northeast of the city, is developed along Pine Promenade, near the Henares River.

The extension of an existing sports center with an indoor swimming pool is carried out with two boxes of different character. The interior box, of glazed walls, accommodates the volume of the swimming pool. The exterior one, a basket of piled up pieces of prefabricated concrete, widens up generating different spaces between both sides, one of which delimits a semi-open space that organizes the access to the complex. From the interior one sees the nearby trees, covering the views of the pool from the exterior fields, except at nighttime, when the building appears like an illuminated beacon.

Using an elementary working scheme, the Center is organized following a linear structure, arranging its compositive elements in a consecutive sequence: link lobby, changing rooms and amenities core, instruction vessel and multipurpose vessel. The volume containing the pools is an open-plan space; the vertical elements of the concrete structure are embedded in the exterior enclosure wall. A flat beam that rests on the heads of the reinforced concrete pillars, located between the two sheets that form the exterior wall, supports the prefabricated beams on which the lightened slabs of the roof rest, the edge of which is tied with a concrete hoop. Due to the proximity of the water level, the building rises above the terrain, placing two vessels on the first floor and leaving the ground floor for storage and installations. This solution relieves the problems that the proximity of the Henares River entails, giving the main hall a predominant presence with respect to the decaying environment, and offering a clearer view of the trees and horizon.

The new construction materializes externally like a great basket composed of prefab concrete girders, which manages to unify the existing levels addressing the visibility problems of the pools, and the ventilation ones of the installations of the lower level. This basket of prefab girders blurs the edges of the construction itself; during the day, the hall and the lobby receive light, from the exterior, through the filter on the facade; at night, the building serves as an evanescent reference from Pine Promenade.