The City Statute of 2001 enacted the urban-policy chapter of Brazil's 1988 constitution, giving cities legal tools to enforce the 'social function' of property and to plan in the public interest. It required larger municipalities to adopt participatory master plans and provided instruments such as progressive property taxation of idle land, the regularisation of informal settlements, and the capture of land-value gains created by public action. It also strengthened residents' rights to security of tenure in favelas and to participate in urban decisions. The law became an international reference for the 'right to the city'.
It is among the most influential pieces of progressive urban legislation, subordinating property to a social function and giving cities tools to regularise informal settlements and recapture land value.