SYMBIONT

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URBAN SYMBIONT

CONTEXT

The African urban environment is host to a diverse range of unique biomes and climatic conditions. However, due to the sprawling of urban centres, ever-increasing numbers of morphological urban nodes arise, shifting the urban edge and eroding productive agricultural landscapes. Older urban centres decay due to the capital desertification, leading to the dereliction of tall buildings. Because of the lack of investment in the region, infrastructure and service provision remains poor and transit systems are decentralised with the urban streetscape dominated by motor vehicles. The harsh streetscape, in urban parts where parks aren’t in abundance, becomes a heat island with poor air quality. This contributes to the pollution of the air in the adjacent built environment. Apart from the local condition, water scarcity, global warming and resource depletion are issues that affect the future sustainability of global urban centres.

CONCEPT

The project proposes the retrofitting existing urban environments with a symbiotic device that encapsulates existing decaying urban buildings. This symbiont interconnects between buildings through pedestrian linkages and a centralised transit node. The new insertion filters air and water, feeding it back into habitable spaces in the host building. This provides necessary sun-shading to openings and introduces new public spaces such as sky parks. It improves and increases the pedestrian environment and provides platforms for new urban narratives. It furthermore compliments the growth of the host building, allowing it to tower above the adjacent context. This renewal encourages the further densification of urban centres. It is envisioned as a prototype, a ‘kit of parts’ that can be adapted globally to specific local conditions and environments. It offers renewal interventions that heal specific decaying urban conditions, contributing to long-term resilience of inner cities.

PROPOSAL

The core of the host building is strengthened and a secondary symbiotic structural system is introduced through a radial of columns. Terraces are created, which spiral upwards

along the building façade. These terraces are interconnected through a wide perimeter pedestrian ramp. They host water filtration wetlands and air regulatory planting, while offering recreational park space to the host building residents. The northern and southern sides of the symbiont are encased with translucent sheeting. Polluted air is filtered before being introduced in the interstitial space, creating an artificial biome in which air is continually filtered and circulated. This filtered air is drawn through habitable spaces towards the host building’s central core which allows waste air to be extracted at the top. At the eastern and western flanks, rain- and grey water is filtered and purified. It is gravitationally drawn through the artificial wetlands and pumped from the base to the sky reservoir atop the building, which is then supplied as potable water for residents. Electricity to service the building is gathered and stored through solar collectors on the roof and façade.

In the Johannesburg city centre, gold-mine closures are leading to the toxic pollution of ground water reserves. Acid mine drainage, associated with gold mining processes, filters into subsurface aquifers, further contributing to urban decay. This new symbiotic structure will evolve to offer vital filtration, drawing the polluted water from the depths of the earth, and re-introducing the much-needed clean water to the urban environment.