Esponjamiento urbano, a Spanish term that literally translates as “urban spongification”, refers to the process of aerating dense, historical urban environments so they become more “porous”. It involves demolishing buildings to make way for public space or public right-of-ways of some sort, thus reducing urban density. A similar concept in French is percement urbain, meaning to “pierce” new avenues through a city fabric; the most famous example being Baron Haussmann’s renovation of Paris.
The pre-modern European city, enclosed by ramparts, was densely built up mainly for reasons of defense. However, these ramparts eventually became ineffective against “improvements” in artillery, at which time they became perceived as a limitation on urban growth rather than a protective shield. Barcelona was late in tearing down its ramparts (Bourbon rule prevented Barcelona from doing so for a century and half as a form of collective punishment), which explains why its historical city centre is so dense. When its walls finally did come down, late in the 19th century, the city quickly quadrupled in area following an urban plan –the famous Eixample grid by Cerdà– that was much more “spongiform” for reasons of public health and transport efficiency; a plan based on “sun, space and green” decades before Le Corbusier would coin that motto.
Many public spaces in the historical centre of Barcelona were created through an “urban spongification” process. Plaça Nova, Plaça Reial, Carrer Ferran, Via Laietana, Plaça de la Mercè (which involved the controversial demolition of a block in which Picasso had once lived), and, most recently, La Rambla del Raval, which was inaugurated only 20 years ago after no less than five city blocks containing nearly 3000 dwellings were demolished, are just some examples. Markets such as La Boquería and Santa Caterina were created out of the demolition of monasteries (in one case after being set ablaze by an angry mob), opening up space for open-air markets that were later covered.
In most cases, the process of urban spongification leaves few traces behind. Plaça Reial may have been carved out of dense urban fabric, but a new, uniform portico and façade surrounding the square unifies the space and covers the urban chaos in-behind. In other, more recent cases, however, urban spongification can be more noticeable, such as when a new “square” is created between party walls in what is essentially an empty lot. No matter how much the newly revealed party walls are decorated with murals, greenery, or even punctured with actual windows, these pseudo-squares will never really work as such unless they eventually also receive building entrances, storefronts, and ground-floor activities that can spill out onto the public space.
Urban spongification is also done by widening existing streets. In these cases, old buildings aren’t demolished to make way for public space, but are replaced with new buildings whose street-fronts are set further back, or that are specifically designed so that more light and air reaches the street. All over Old Barcelona there are streets with varying frontages; a mix of old buildings yet to be replaced that seem to “invade” the sidewalk, and newer, slightly taller buildings that are recessed behind wider sidewalks. Probably the best example of an architectural design that performs urban spongification is a modest 1994 mixed-use building by Josep Llinàs that slightly widened and greatly brightened a narrow street (Carrer d’en Roig) by virtue of its recessed lower floors and fragmented upper volume.
Esponjamiento urbano can indeed take many forms. It can come out of a “grassroots” process, such as torching a monastery, or it can be officially implemented planning policy. It can involve elaborate architectural scenography to make itself imperceptible, it can leave scars visible, or it can be architecturally designed to perform as such. What is certain however, is that it introduces light, air, and sometimes greenery in places where these are an exception rather than the rule. But is urban spongification still necessary today in a city such as Barcelona, where households have shrunk in size, tuberculosis is no longer a threat, and homelessness is on the rise? In many other parts of the world, such as North America, once sprawling cities are now becoming denser. Maybe it’s time to ask whether esponjamiento urbano remains as necessary as it once was.