This article examines the relations between practices in informal land transactions under customary tenure and spatial differentiation among suburbs in the periphery of the city of Pointe-Noire, Congo-Brazzaville. Urban sprawl is a permanent feature of urbanisation in Congo-Brazzaville that not only propagates slums for low-income dwellers but also entails locally embedded ways of building the city in the absence of state-led planning. The case of Pointe-Noire shows that large tracts of customary land are sold without public control, a process accompanied by the emergence of new suburbs with different stylistic patterns of housing. While suburbanisation does carry the potential to improve the quality of housing by attracting wealthy residents, it exacerbates spatial fragmentation and the exclusion of certain groups in the population from access to both land for housing in upmarket suburbs and public services. Powerful actors tend to profit most from informality.