According to the records of the Municipal Housing Department of Sao Paulo City Hall, they are generally formed by the combination or juxtaposition of favelas, upgraded areas, irregular allotments and tenements. Tenements, precarious collective rental housing concentrated in central areas of the city, are not subject to the same upgrading and land regularization policies as the other types.
It is estimated that about 9.4% of the 4.9 million households in the municipality of Sao Paulo (IBGE, 2022) are located in favelas and upgraded areas. The growth of these neighborhoods occurred mainly in the 1970s and 1980s.