Exclusionary zoning is the use of zoning laws to exclude certain types of people from a community. Exclusionary zoning laws began to be used in the United States in the late 19th century. Exclusionary zoning rules are still used today across the country. A common type of exclusionary zoning rule is a minimum lot size rule. This type of rule makes it hard for poor families to build a house on a small lot that they could afford. Exclusionary zoning rules make it hard for poor families to find housing in a community.