The Thermal Centre is located in the Justo Gómez Salto Municipal Sports Centre de San Fernando de Henares, a location close to Madrid, and complements the range of sports on offer at this facility. For this purpose, it presides over the square that acts as a distributor of all the activities of the Sports Centre. 

Access is through the square, from the south side, guided by the sinuous undulating forms of the spa and by the channels that reveal the aquatic theme of the building, allowing us to enter the main vestibule, showing us the way through a large pane of glass and reflecting the connection between the interior and the exterior.

The main façades, south and east, present a curved glass space on the upper floor, the main floor, which responds to the more playful area of the square and forms a contrast with the more functional parts of the Spa, made up of more rounded geometric elements, using exposed concrete planes.

The building is therefore a closed box that opens onto the square to reveal its public vocation through a great translucent glass curtain that screens the views in both directions from the interior and the exterior, giving great clarity and luminosity to the main space of the swimming pools. This glass skin faces south to optimize the energy efficiency of the facility. These passive energy-saving measures, together with other active measures (solar panels, etc...) make the building energetically sustainable.

The functional layout is based on a ground floor where, in addition to the entrance, the entire facilities area is located, so that they are easily accessible, and a first floor where all the activities of the spa centre are carried out, together with locker rooms and service areas. A lift, suitable for people with reduced mobility, and the main staircase connect the entrance hall, on a double-height, with the upper floor, where the reception of the Centre is located, giving direct access to the changing rooms, which are naturally lit by two large skylights. From there, we go out to a hall where the cloakroom lockers, the UV rooms and the medical centre are located. On entering the main hall, after leaving the changing rooms, the visitor finds a large space, illuminated from the left by a large translucent glass panel that filters the entry of natural light into the relaxation area of the swimming pools. To the right and in contrast, delimited by a colored glass front in different colors, are all the functional parts such as massage rooms, sauna, steam bath and specialized showers, which complete the range of services aimed at improving the health of users.

Concerning its relationship with the surroundings and the square, from the main entrance to the Spa, a water channel is cut as if in a game by other channels, ending in a pool that recycles the water from the Spa installation as well as part of the building's rainwater and which in the future could be used to recycle the water from the three installations that drain into the square and be used to irrigate green areas. To recycle the chlorinated water, it needs ventilation and exposure to the sun, hence the need for this open channel.

The structural system is resolved with a reinforced concrete structure, which optimizes durability and maintenance.