Prior to 1914 owner-occupation was unusual, with even many landlords renting the houses they themselves lived in. The inter-war years, and particularly the 1930s, witnessed the start of a trend towards Britain becoming a nation of owner-occupiers and of a popular perception that ownership was socially superior to renting. The 1930s owner-occupation boom has traditionally been portrayed as a process from which the working class were largely excluded. However, working-class families (particularly recently married couples) played a substantial role in this boom. This transition was the product of falling building costs, mortgage liberalization, and an intensive marketing campaign by the two key components of the private house-building value chain: the house-building firms that determined the character, design, and location of the final product, and the building societies that provided the all-important mortgage finance.