The widespread existence of slums in developing countries is not a new phenomenon in economic and social history. At the end of the 19th century in England where the industrial revolution started and at the beginning of the 20th century in continental Europe, housing and general living conditions of workers were unbearable. The living conditions of workers and their families gave rise to powerful political movements, including revolutions. The trade unions and the social-democratic political movement were the main driving force for the gradual improvement of the living conditions of workers and their families