In Kenya, urban planning is particularly weak and the major towns have seen a mushrooming of slums on the one hand, but also of rich gated communities on the other. Segregation between the rich and the poor is becoming more pronounced. In these circumstances, a residential association in Karengata, a wealthy district in Nairobi, has decided to design its own urban planning project, against the will of the local authorities, but with the support of the Ministry of Local Government. Its main argument is based on the fact that it is a participatory and community-based approach, aimed at the "sustainable development" of the area. Is the participatory approach therefore a first step towards urban secession and social injustice?