The challenges, methods, and opportunities of understanding informal urbanism: a case study in Lomas del Centinela, Mexico

Informal settlements are a defining feature of urban growth in many regions, yet they remain difficult to study because of fragmented infrastructure, irregular land tenure, and limited official data. These challenges hinder progress toward Sustainable Development Goal 11 on sustainable cities and communities. To address this gap, we review the historical evolution of methods for studying informality, from early observational research to recent participatory and technological approaches. We then present a multi-year case study in Lomas del Centinela, Mexico, where a range of information-gathering techniques were used to address critical gaps in energy, water, food, mobility, and safety. Methods included surveys, interviews, behavioral mapping, sensor deployments, remote sensing, and videography. Together, these approaches provided a detailed view of everyday practices and infrastructure conditions, while also supporting community-led interventions. The findings highlight the value of combining flexible, context-sensitive methods to generate meaningful insights in informal urban contexts. They also offer a model for future research and policy aimed at improving the quality of life in marginalized communities. This approach shows the potential to make cities more sustainable and to strengthen national and regional planning through bottom-up community participation and the use of novel data technologies.