French public housing is commonly understood as a social policy whose aim is to sustain decent housing for low income populations. The present work demonstrates that this aim was early challenged by pro-natalist and pro-family goals. During the first part of the twentieth century, consequences were limited because of the weakness of public policies. On the contrary, after the World War II, the implications of this pro-natalist scheme became more important when the major housing policies of the Trente Glorieuses such as the housing allowance took effect. Created in 1948 to compensate rent increases and encourage good housing, housing allowances were meant for families with children and excluded other households such as the elderly until the 70s. Our study demonstrates the importance of pro-natalist and pro-family ideology in the construction of French housing policy.