Migration from countryside to cities or by refugees from conflict zones will require us to build massive amounts of housing. Given there may not be enough resources or enough time to deliver quality solutions, we will need to develop new strategies—or revisit a few forgotten ones, to be more precise. Incrementality was a quite common strategy in Latin America in the late 1960s and early 1970s. It was implemented in various versions as a way to provide mass access to sanitation (public health being at the core of the urbanization process) and land (preventing informal slums from illegally seizing private property).
In most cases it was a question of defining a basic geometry to determine lots and streets along which basic services such as water, sewage, and electricity could be installed. Unfortunately, even though sanitation improved and legal property was defended, in most cases overall urban quality was rather poor, perhaps because the ratio between public and private space was far from optimal and perhaps because the principle that prevailed was that of one family per lot. Over time, when people began to build on their own, more than increased efficiency or intensification of land use, the end result was an overcrowded, low-standard urban environment.
We therefore need a second generation of incremental urbanization. A clue is offered by the BeL Architects project “Grundbau und Siedler”, presented at the IBA Hamburg in 2013. This is a kind of “Domino House” whose structural simplicity, like the scheme developed by Le Corbusier at the beginning of the twentieth century, allows for an easy, fast, and inexpensive construction that can easily be completed and modified by the owner later on. But BeL introduced a couple of very crucial differences: the construction is multistoried (and not just two-storied), and its scale is consequently collective rather than individual. What is interesting in BeL’s proposal is the awareness that the openness of the system not only allows for a strategic building efficiency but also allows for cultural flexibility. The neutral frame of beams, slabs, and columns can acquire a specific architectural language depending on the cultural background of the people who occupy it. Considering the enormous need for incremental housing, its obvious gains in efficiency, and the sociopolitical advantages it offers, it is surprising how few examples of incremental approach there are in the world.