The US applies several zoning categories, such as residence, commercial, manufacturing or special purpose district. Every zoning district has different kinds of regulations and restrictions on building’s bulk, parking, open space, FAR, height regulations and setbacks.
A setback is the minimum distance that buildings on a lot need to keep between each other, roads, highways, rivers, railway tracks, fences and other structures. Setback restrictions can be set by the state or federal government through ordinances or building codes. For instance, if the regulation requires 10 feet setback, then the buildings need to keep 10 feet distance between each other. Setbacks are highly important for privacy, environmental protection and safety.
Setback restrictions are different from place to place, district to district (city/rural area), depending on the zoning laws of each district. In dense big cities the setback is often small, whereas in rural areas it is bigger. For example, a setback in the densest single-family residence district of Chicago is 5 feet, while in the multifamily district it is only 2 feet. Some front setbacks in business districts is 0 feet, which means buildings and other structures can be right next to the sidewalk. (Hansmann, 2016)
Until 1916 when the first zoning law was accepted, there were no setback regulations. Thus, the setback between houses which were built before 1890 was very close. Starting from 1920 setbacks started to increase from approximately 5 feet to 15 feet. Later, due to the increasing number of cars in our societies, the setback regulations started to require more spaces between buildings and streets.