Participation as a basic principle
Many times during his long career as architect and urbanist, Christopher Alexander was asked to plan and construct social housing. In every case, and often in opposition to the brief provided by the government agency that hired him, he insisted on user participation. He clearly saw that this was the only way to produce built forms that are “loved” by their occupants (Alexander, 2001-2005; Alexander et. al., 1985). Each of his projects began with the essential framework of involving future users in planning their living space, and shaping the configuration of streets and common areas. In some cases, this led to the support being withdrawn by the sponsoring government, which surmised that such a scheme would severely weaken its control over the geometry of the project.
We believe that Alexander was entirely right in insisting on participation as a basic principle. He correctly predicted that housing built by someone not involved in the world and daily realities of the resident would lack certain essential qualities. As a result, its inhabitants could never love the place. Even if the houses were all built following exactly the same modular typology, participation in the planning or building process guarantees that the eventual users have a personal stake in the final product. Most people could not care less about a design’s formal virtues: they just want something they can truly consider their own.
Alexander’s most recent work (Alexander, 2001-2005) establishes a temporal ordering for any construction if it is to be adaptive to human needs. That is, it matters enormously what is designed and built before, and what comes after in the sequence of design/construction. This practice was followed since ancient times in the Near East and was codified in Byzantine and Islamic urbanism, which influenced all regions affected by these civilizations (Hakim, 2003). Its scientific foundation as part of the general processes by which a complex system is evolved is a new contribution, and has been theoretically shown to be crucial to the success of any project. It is now possible to outline the correct order in which components of a housing development can be built to ensure sustainability.
Steps in designing healthy urban fabric
For example, Alexander reveals the steps in designing healthy urban fabric. These of course depend very much on scale. Since one priority is how a settlement connects to the rest of the city, an area of up to 1 km2 will usually be tangent to one of the main streets, whereas areas larger than that will probably need a major street that goes through them.
1. Major circulation routes are determined as part of the integrative core of the city and the adjacent urban area.
2. Major public spaces are identified to tie in with topography, natural features, and major lines of movement.
3. Secondary street alignments are laid out making 60-150 meter intersections with major streets and spaces.
4. Pedestrian space is defined by the building fronts, and is accessed by, but physically protected from vehicles.
5. Buildings are situated so their front walls define the urban space as coherently as possible — no setbacks, and few gaps.
6. Roads arise as the consequence of linearizing and connecting segments of well-defined urban space. If the living form of the place is to be respected, roads CANNOT be built first, especially if their perceived functional requirements are then allowed to dictate the form, scale, and quality of urban spaces.
Failure to follow this sequence inevitably leads to dead urban fabric. The correct application of this sequence can only come about after convincing the authorities to implement a different construction practice than is usual nowadays. Nevertheless, there are overwhelming theoretical reasons for insisting on this sequence. The steps were followed in countless traditional settlements, forming towns and urban quarters before the era of industrialization. When the main mode of transport is still pedestrian and low-speed traffic (animals, carts, only a few jitney buses and pick-up trucks, etc.) it is easy to give priority to space and buildings. Once the automobile takes over, however, it begins to dictate a new priority, which reverses the above sequence. The planner then sacrifices traditional urban fabric to fast transversal movement, and this ultimately leads to a dysfunctional and unsustainable design.
Alexander has applied these principles in several projects of social housing, including Santa Rosa de Cabal, Colombia (Alexander, 2001-2005: Book 3, pages 398-408) and Guasare New Town, Venezuela (planned but not built) (Alexander, 2001-2005: Book 3, pages 340-348). Another successful recent example is Poundbury, England, by Léon Krier (1998). Interestingly, the latter is an upper-income development, in which a significant fraction (over 20%) of subsidized residents are included; those are financed by the Guinness Trust, a non-governmental organization. We are going to extract working rules from those examples, and present them in this paper.