The Chicago Housing Authority is the third largest public housing agency in the nation. It serves more than 17,000 low-income public housing households, providing safe, decent and affordable housing in healthy, vibrant communities.. Public housing provides homes for families, the elderly and those with disabilities from scattered single family houses to apartments for elderly families. The CHA is 87 percent complete in a comprehensive, historic overhaul of 25,000 public housing units, providing residents a firm foundation on their road to self-sufficiency.