The building on which the gardens sit is supported by prefabricated concrete elements covered by a glass facade that allows the views of the city from the subway and vice versa.
Description of the project by Sergi Godia and Ana Molino
The layout of the train and subway routes in the Sants neighborhood (Barcelona) has created an open wound in the urban fabric during the last century. With an average width of 30 m and an 8-way platform, it has divided the neighborhood along 800m into two virtually separated parts - starting at Plaza de Sants and running towards Riera Blanca Street -, creating the consequent urban dysfunctions, in terms of noise pollution and degradation of its surroundings.
In 2002, the city administration decided to start up the urban renewal project of the Sants railway corridor, thus initiating a complex process involving three public administrations and the civic associations of the Sants district.
Having discarded the option of burial of the railway corridor, due to technical and economic problems, it was proposed to be confine the subway lines inside a light and transparent box in the most part of the route, transforming its the cover into a high and 800 m long garden walk, which in fact would be later extended to the neighboring municipalities: Hospitalet, Esplugues and Cornellá, giving rise to a "green corridor" of 5 km in length.
The support structure of the building-container is made of prefabricated pieces of concrete in a diagonalized sequence that take the form of a large Warren beam that evokes the old railway bridges, leaving large empty triangles propitious to its glazing which allows to maintain the vision of the train through the city, while minimizing its acoustic impact. The fact of not completely glazing the building opened the possibility of projecting three large green slopes that ascend to the deck from the low points of the environment . These slopes "anchor" the building to its surroundings, allow the vegetation landscape of the deck to spill into the side streets and support pedestrian ramps that give "natural" access to the deck.
The roof of the building is elevated between 4 and 12 meters from the surrounding streets and consequently its gardens become a sightseeing spot over the city. The projects begins in the Plaza de Sants with an urban space that, covered by a large shadow, serves as the entrance to the gardens, that with an average width of 30 meters finish in the Riera Blanca Street, with a total route of 800 linear meters. The gardens are structured in two linear paths: one on the north side of the deck, very shaded by the trees and another on the south side, permanently sunny. The intermediate space between both roads is configured as the spinal cord of the gardens based on the configuration of a complex artificial topography with a high density of trees and a rich plantation of shrub and upland vegetation, selected according to a very selective color palette . The elevations of the topography, reinforced by the density and strategic position of the masses of trees, favor the creation of areas in which the walker loses the sensation of being inside the city and generates that of being immersed in a natural environment.
Along this naturalized route there are three spaces with a different treatment because they constitute the joints in the system of access to the deck, which include: 5 elevators and 2 adapted ramps, complemented by 3 stairs and 4 escalators. These three spaces disrupt the plant sequence and are characterized by large pergolas that support photovoltaic panels that cover part of the energetic consumption of the roof and generate shade spaces.
The type of trees most used have been Tipuanas, Sophoras, Koeleuterias and Malus evereste characterized by presenting a yellow and white flowering. In terms of upholstery and shrubs the plantation has been distributed among the lawns, the Bulbine, the red Salvia, the wild roses and the Hedera helix in the sunny part with flowering of bright and warm colors and the Hedera helix, the Vinca, the Gaura And the white Lantana, in the most shady part, all accompanying the North route and dark green background and white flowering.
Next to the landscaping of the deck have been planted along the whole North facade the following climbing plants: Hedera helix, Trasch. Jasminoides, Tricuspidata, on a system of cables that will allow them, in the short term, to cover all facades except the glazed areas.
