With around 883 million urban dwellers living in slums and many others yet to be measured facing inadequate and unaffordable housing, this indicator is strongly associated with other social challenges such as low educational attainment, crime, and poor well-being. The Global Strategy for Shelter to the Year 2000 and the enabling approach have dominated housing policies since Habitat II and the 1996 Habitat Agenda, which rests on two pillars: housing for all, and sustainable human settlements in an urbanizing world. Today more than 100 countries have a constitutional provision on the right to adequate housing.