Informal housing and marginal settlements

Abstract

Marginal settlements, slums, squatters—these are only few terms describing informal settlements. As the definition of ‘slum’ is controversial, counting slum dwellers is a difficult venture. In the first section, this chapter provides an overview about common definitions, develops a low-cost housing typology and explains how the different terms are used. Characteristics, formation processes and spatial patterns of slums are addressed. A second section is concerned with the global debate on the challenge of slums reflected in several global summits on housing questions. The principles adopted and initiatives introduced (e.g., the Habitat Agenda) are explored, from the first World Conference on Human Settlements in 1976 (Habitat I) until the adoption of the Sustainable Development Goals in 2015. Highlighting the importance of the challenge of slums, the last section gives an overview about current estimations about the state of the world’s slum population, its spatial distribution and prospected development.