Incremental light space: Reducing socio-technical night-time public space inequality in Bogotá through lighting technology and design for informal settlements

Abstract

In view of the more than 1 billion informal settlement dwellers worldwide, this transdisciplinary research project examines the implications that light has on their nocturnal living conditions. In this context, public lighting is viewed as a cross-cutting night-time enabler. Informal settlement lighting was examined in Colombia’s capital Bogotá in a both qualitative and quantitative multi-method case study. The researcher himself spent several days living in a settlement, which is why the case study includes an ethnographic perspective in addition to a technical and architectural one: the public space was approached as a social space. The research revealed socio-technical night-time inequality in Bogotá: on the one hand, ‘formal’ lighting provided by the authorities often fails to adapt to the dynamic informal urban context. On the other, self-built ‘informal’ lighting installed by the settlement dwellers does not comply with product safety and light pollution standards. Moreover, the lighting conditions tend to be poor in terms of the support of night-time safety and security. Despite these conditions, outdoor night-time activities play a crucial role in community life: informal settlement dwellers socialise during hours of darkness and many of them rely on public transport during night-time to commute to work. However, their access to public space is negatively affected by the given lighting conditions. An alternative lighting strategy was developed based on the case-study results in order to address the shortcomings of the current lighting conditions. Part of this strategy includes a newly designed luminaire family for which several 1:1 prototypes were built. Its design relies on a co-creational approach that made use of the settlement dwellers’ local knowledge. This strategy would not only improve the lighting conditions, but also goes beyond illumination by using communication technology that enables warnings of landslide risk. A crucial aspect of this strategy is to provide public lighting in an incremental and participatory way, following the different phases of incremental dwelling construction. Grid-independent and sensor-driven pole-mounted luminaires with an adaptable luminous intensity distribution are proposed for the foundation phase, with span-wire mounted luminaires recommended for the consolidation phase of a settlement. Computer calculations showed that lighting design of this type is able to address the shortcomings of the current lighting conditions, which tend to be characterised by low illuminance uniformity as well as high degrees of light pollution and light trespass. Finally, Colombian policy-making stakeholders were approached in order to explore the extent to which the proposed lighting technology and lighting design could influence a new lighting policy for Bogotá. It was found that the grid-independent and sensor-driven luminaires represent promising pil-lars of a lighting policy characterised by an instant but temporary provision of public lighting in informal neighbourhoods. Moreover, the life-saving potential of the landslide warning technology seemed likely to justify the provision of luminaires by the authorities in non-legalised areas. Furthermore, the lighting recommendation for the consolidation phase of a settlement – the proposed use of span-wire-mounted luminaires – was appreciated, since it is based on a ‘human centric’ lighting design approach. At the same time, a number of legal and regulatory obstacles would still need to be overcome by the different departments before the implementation of these policy recommendations can be realised. This includes the adaptation of Bogotá’s planning regulations to the special characteristics of informal settlements. The incremental lighting strategy developed for Bogotá also appears promising for settlements in different local contexts such as India, Thailand, Brazil and Vietnam. However, its implementation would require a reconsideration of the status quo of UN-Habitat’s current informal settlement lighting recommendations. Achieving the implementation of this lighting strategy would have a positive impact on several of the United Nations’ Sustainable Development Goals, namely on SDG 7, SDG 9, SDG 11 and SDG 15.