The distribution of the houses is projected from the central wall, inside the residences the kitchen-dining room communicates with the kitchen thanks to two holes in the central wall of the building. In turn, the interior patio is connected with the exterior views, achieving great luminosity in the apartment and energy savings.
An energy solution is found that makes the building work in a similar way to the original. The roof is insulated and carpentry and glass are incorporated that thermally and acoustically insulate the exterior, a street with great movement.
La carbonería by Ángel Borrego Cubero. Photograph by Simona Rota.
Project description by Ángel Borrego Cubero
The rehabilitation of La Carbonería owes its shape to several intertwined stories over a century and a half, from the impact of the virulent debates surrounding the birth of the Eixample, conceived by Cerdà, to the adoption of the unusual geometry of the building by its promoter until the disappearance of its original staircase following its eviction in 2014, and the arrival of a new property two years later.
"There is a material and energetic wealth embedded in the stories of the place that we must incorporate into our designs so that they are truly sustainable"
Ángel Borrego Cubero.
La Carbonería, also known as Casa Tarragó, is a modest residential building from the 1860s, which gained notoriety between 2004 and 2008 when it was occupied and two large urban art interventions were carried out on its façade. Its forced evacuation in 2014 made headlines and the building became a graphic and political icon of Barcelona. When the new owner of the building asked us to rehabilitate La Carboneria, many doubts arose in the face of such a potentially problematic project. However, the building kept a much bigger surprise.
In 2015, the City Council declared it protected heritage as it is the oldest standing building in the Eixample, the innovative urban plan conceived by Ildefons Cerdà to expand 19th-century Barcelona beyond its obsolete medieval walls. During its definition, there were heated discussions between Cerdà and Barcelona City Council: the former had projected a rational and socially progressive extension, approved by the Ministry of Public Works, while the latter had tried to carry out an urban expansion with a more symbolic design, with great avenues and symmetries for the future capital of Catalonia. The plan of the Barcelona City Council failed, but the controversy moved to those areas where it would have been possible to locate avenues in the Old Regime style.
La carbonería by Ángel Borrego Cubero. Photograph by Simona Rota.
This prolonged confrontation ended up affecting Narcís Tarragó, the original promoter of La Carboneria, since the plot of his future building was affected by the proposal for a large boulevard, in the style of the Champs Elysees in Paris, coinciding with the old Camino de Ronda, and that Cerdà rejected. The original design of the building reflects his uncertainty: Mr. Tarragó decided to place facades in all orientations of the building… just in case! Of course, the courtyard façade was completely hidden as the grand boulevard was discarded in favor of the more modest Ronda de Sant Antoni.
In order to comply with the patrimonial protection conditions, the façade of the patio had to be returned to its original state; and its large windows recovered. These gaps were designed by the promoter in 1864 to face the Camino de Ronda and a possible Boulevard much wider than the current Ronda de Sant Antoni, desired by the City Council, but rejected by Cerdà. Now, however, they would look questioningly at two blind party walls.
The rehabilitation project recovers these stories and moves the disappeared communications nucleus out of the building, jumping over the old Camino de Ronda through some walkways that make this interior façade visible and integrate it into the daily life of the building. The walkways, the nucleus, and the new metallic dividing wall generate a three-dimensional community space, a movement of people and effects that, in some way, simulate the experience and the changing vision of the boulevard that never came to be.
"The façades of this small but prodigious building represent different ideas of the city, of politics, and of the relations of Catalonia with the rest of Spain during the last 150 years. The history of the building has been the greatest resource of the project, as relevant as the precision in its energetic or material balance."
Ángel Borrego Cubero.
The walkways, jumping over the old Camino de Ronda, bring this hidden façade closer and make it visible, which becomes part of the life of the residents, and becomes visible for each visit. The municipal technicians supported the idea, despite being formally and normatively unorthodox (the heritage protection regulations required the restoration of the facades to their original state, something that the footbridges, in essence, modify) because otherwise, the façade would have remained hidden from everyday life and, with it, a representation of the events that gave rise to modern Barcelona would remain invisible.
La carbonería by Ángel Borrego Cubero. Photograph by Simona Rota.
Project details
The building seems turned upside down. It has its most striking façade hidden in an inner courtyard and, to make it accessible, its communications core has been moved outside. The structural design of the communications core, the walkways, and the dividing wall seeks to feed from this situation. The broken footbridges are supported without props or tie rods (that is, without a vertical component), but by crossing beams in a plan under said footbridges, achieving a structural function that is not obvious to the naked eye, but allows more freedom of layout. in such a reduced space and a more aerial appearance for the paths that arrive at the door of each house. The structure of the dividing wall, elevated up to the 7th floor, allows passage through it, on the ground floor from the lobby to the elevator and stairs, and on the top floor to reach the roof. It is also supported for planters and their irrigation, photovoltaic pre-installation, and a series of mirrors that direct sunlight to the lower part of the patio in the winter months.
The restoration maintains most of the pre-existing features and aims to recover the diversity of layers that have defined its character up to the present. The original structure of the building was maintained as much as possible. Only the slabs of the Catalan roof were replaced because they were in poor condition. The rest of the slabs, walls, and foundations were reinforced to the extent of their requests, to accommodate them to current requirements. These reinforcement works were mandatory, but once they were done, the surplus payloads available were used to make the roof accessible and to place a 1m-deep collective pool on the wall.
La carbonería by Ángel Borrego Cubero. Photograph by Simona Rota.
The distribution of the houses emphasizes the central wall, associating storage spaces and facilities with its layout to reinforce it visually. The space between this solid and the patio windows is reserved for the kitchen-dining room, connected to the living room thanks to two holes in the central wall, which, in turn, visually connect the interior patio with the street, chamfer, and layout of Sow. Other advantages of this solution are effective cross ventilation and natural lighting that takes advantage of the entire solar path, thus contributing to energy savings from passive solutions. Together with the use of original, breathable materials and other relatively natural finishes, such as pine wood with wax and oil, generous space is achieved with little impact from volatile substances.
The installations are concentrated in the roof frame, which has a position similar to the original. All vents and machines were matched to this volume. The design of the roof tries to integrate volumes and materials with those of the context and the little roof gardening is considered as a reflection of the existing one on the hill of Montjuic, to which the pool looks.
Exhaustive energy studies were carried out, with complete simulations of the building, until a satisfactory energy solution was found that allowed the building to function in a similar way to the original, a decision that, in the architect's vision, has didactic value for the building sector. Insulating the roof together with the incorporation of carpentry and glass designed to insulate thermally and above all acoustically from the busy Urgell Street, an excellent energy classification was obtained (B, which implied, in this case, average consumption of less than 60% of the media) without the need to add insulation to the exterior facades, an option that would have damaged the exterior of the building, would have subtracted space from the interior and would have created other problems typical of the most suitable multi-layer solutions for extreme climates.
La carbonería by Ángel Borrego Cubero. Photograph by Simona Rota.
By regulation, the façade had to recover its original state. Materially it would also have been impossible to maintain the existing mural due to the deterioration of the base stucco under the windows, which was coming off. On the other hand, its reuse as a public façade of a renovated building seemed very doubtful, something possibly contrary to the original intention of its authors. Efforts were made to maintain Mr. Garriga's traditional furniture store on the ground floor of the estate.
