Future horizons

projects include strategies to optimize the use of resources and lower costs. For example, in Casas Melhoradas locally produced prefabricated elements were developed as an alternative mode of construction in order to minimize the timespan of construction, reduce waste of construction materials, and advance compact city development through demonstration houses. The modular design toolbox developed in the Tana Toilet Blocks project sought to decrease the resources spent on the design and planning of projects while advancing best practice solutions. The experiments with plastic waste sought to advance principles of circular economy in the construction sector in Maputo in order to support waste recycling. Perhaps most notably, the Kyangwali Spatial Planning Project tested alternative low-cost solutions for land surveys and land use management which are linked to the policy proposals concerning innovation in these fields. Accordingly, the project may provide lessons for future application of new methods for land management in informal settlements. Finally, the projects discuss issues relating to urban densification, access to sanitation, as well as innovation in planning and land management which are essential issues presented in the research. Accordingly, these projects have arguably informed the research through tacit knowledge accumulated throughout the practice-based work and provided alternative mediums to the academic work for discussing central issues in this thesis.

FUTURE HORIZONS

This section discusses the frontiers of the studies of urban morphology of informal settlements. In general, the findings presented in this thesis on the significance of ‘informal land supply’ and the impact of urban planning are based on relatively limited data. Accordingly, further studies are needed for advancing the understanding of these issues. Such studies will likely benefit from including l multidisciplinary researchers and analyses based on larger data sets.

Several studies suggest that public health outcomes are worse in informal settlements than formal urban areas (Snyder et al., 2014; Sverdlik, 2011). Recent studies have documented a correlation between public health and urban form (Shen & Lung, 2020; Fathi et al., 2020; Hankey & Marshall, 2017). However, limited studies have investigated the relationship between public health and urban form of informal settlements even though several of the indicators of urban slums such as unsafe housing, inadequate access to safe water, and inadequate access to sanitation are linked to spatial factors (Mottelson & Venerandi, 2020). The lack of knowledge on the relation between urban form of informal settlements and public health may compromise public policy in containing the spread of diseases as well as decrease the effect of urban planning efforts to improve livelihood in such urban areas. Accordingly, studies on the relation between urban form of informal settlements and public health conditions may produce interesting and useful results.

The link between transportation costs and distribution of densities is widely acknowledged in urban economics (Glaeser, 2020). Kombe (2005) argues that the organic urban form of informal settlements does not reflect mainstream economic models. The papers presented in this thesis contribute with some possible explanations to reduce this knowledge gap. Namely, that government restriction of informal land supply may lead to significantly higher population densities in informal settlements in cities with large populations financially excluded from the formal housing market. Furthermore, the studies suggest that the ‘collective investment capacity’ and the time of the establishment of the settlements may account for increased housing supply elasticity. However, the relationship between socio-economic conditions and urban form of informal settlements is poorly understood. Furthermore, as argued previously, the relationship between densities and the time of the establishment has not yet been studied. Accordingly, longitudinal studies on the relationship between socioeconomic conditions and built densification may generate interesting and useful results. Do higher income levels lead to urban densification? Or do people with more resources seek more open space and thus contribute to urban expansion? No studies have investigated these issues in the context of informal settlements in sub-Saharan Africa and the answers may be relevant in addressing the overconsumption of resources linked to contemporary urban expansion in the region.

Mottelson (2020a) suggests that urban density and public space ratio of informal settlements are not interdependent and that public space ratio likely is linked to average block sizes. These conclusions need corroboration based on larger scale data sets and more in-depth quantitative analysis. Further studies in this field will likely find links between built densities and street configuration such as higher built densities along internal main streets which score high on centrality measures, as such areas would likely have higher levels of economic activity and thus provide resources for investments in densification. Vice-versa, areas around dead-end streets with low measured centrality will likely show lower levels of built density. Furthermore, Venerandi & Mottelson (2021) find low-density fringe blocks in centrally located informal settlements as much space in these blocks are used for parking. This finding contests the findings of Hillier et al. (2000) who suggested that the built form of fringe blocks consolidates in centrally located informal settlements which are integrated in the formal urban fabric, due to increased economic exchange with the surrounding urban area. Accordingly, further research on this would arguably be significant.

Visagie & Turok (2020) examine the conditions for compact city development in informal settlements in sub-Saharan Africa. The extra costs of multi-story construction are arguably an important economic barrier for urban densification in the region (Mottelson & Andersen, 2018). However, increasing costs of land caused by growing urban populations may provide incentives for densification. Specifically, the equilibrium between the cost of land and the extra costs of multi-story construction per area may account for the conditions that will enable large-scale densification based on market conditions. Accordingly, research on the