Promiscuous buildings: how to make the city denser
Why is density frightening? Because until fifty years ago, unless expressly prohibited, property owners could add floors, increase building volume, and change the use of their properties without any repercussions for the city. If more wasn't done, it was because the load-bearing walls could only support two or three additional stories, not much more. The resulting appearance of cities was quite wild, with blocks of streets that, overnight, had taller facades without any increase in street width, thus losing light and air inside the dwellings.
The 1975 Land Law solidified the idea that land should be used in accordance with the social function of property and assigned to urban planning the objective of balancing benefits and burdens. It also stipulated that landowners must be required to build within specific timeframes, but in practice, this has never been enforced. What has taken hold, however, are the land transfers: if landowners wish to build, they must cede land to the respective city council for streets, gardens, or schools (initially); for some years now, they must also cede a plot large enough to accommodate the corresponding social housing. In other words, transforming a piece of established urban land now implies having to widen streets, create green spaces, allocate land for public facilities, and provide land for social housing.
To fit all this into the same space occupied by the old houses and buildings, it's clear that the only solution is to grow vertically. We often only count the floors: in an area that previously had a ground floor and three upper floors, the plans now show six or seven. But in return, the neighborhood gains a nice plaza and a school, a gym or community center, and affordable rental apartments. Sometimes, the new development is bigger, taller, longer, and less interesting than the small-scale city that has developed over time. It's a long and difficult process to explain without diagrams, but it's one of the reasons why the regeneration of established cities generates resistance: if it's not planned well, the new development creates an insurmountable barrier with the surrounding area, which has much to lose.
I was thinking about all this as I walked from the wonderful streets of Sant Andreu to La Sagrera, covering on foot what I normally do by train, when I arrived at the Camp del Ferro pavilion. It's a marvelous building, and I say this after four years of visiting sports pavilions in all kinds of Catalan towns. The one at Camp del Ferro is ingenious because it buries one level and stacks two courts above it. It's a building typical of dense cities like New York or Hong Kong, creating a large plaza, very useful between matches. As it rises in height, the building provides a plaza within the city and improves sunlight on the street and pedestrian traffic around it.
The building is near the Llotja art school and the Fabra i Coats industrial park, and it's meticulously constructed with bricks and ceramic latticework of varying sizes, so when you approach it, you can't quite place it—is it an old industrial building, a library, or an auditorium? But you know it's an important building for the city, because of how it creates a dignified intersection and a playful roof, with inverted arches that make you do a double take. And suddenly, a building that could have been a bottleneck in a densely populated neighborhood has created a huge plaza where everyone can fit without feeling cramped. From the outside, it's a seemingly robust and opaque building. But inside, it's bright and airy, even though there's a considerable distance between the facades.
I understand that urban regeneration can initially generate resistance and suspicion regarding the potential benefits for landowners or the increased foot traffic that new buildings might ultimately bring. Furthermore, I believe that the usual explanations for urban transformation are lazy: cities deserve projects conceived in terms of open spaces and solids, facades and streets, plazas and corners, and should avoid the common practice of increasing building density to compensate landowners. The debate on density is necessary and can lead to ingenious solutions, such as that of this pavilion.
Conversely, there are very tall buildings that can generate low densities, such as the corporate headquarters in the towers along the Diagonal, which are empty on weekends, or university campuses, which seem frozen during the summer months. Regenerating urban fabric doesn't mean simply remodeling interiors; it means thinking about making space for more people, but in a way that benefits the surrounding environment. This implies moving beyond unilateral discussions between developers and city councils and starting to design with current and future residents. Is a shared design with neighborhoods more difficult? Perhaps, but the complex debate surrounding the densities of the 50,000-square-meter plan will require sharpening our pencils to envision new, overlapping uses and more diverse building types.
