Single-family is a legal zoning regulation which allows only for single-family detached homes on properties within the zone. The zoning regulation emerged in the 20th century, restricting the construction of high rise residential housing, condominiums and duplexes, and is nowadays the most common form of zoning in the United States.
The first time a single-family zone was established was in East Berkeley, California, in 1916. The language of the zoning regulation and contracts specified the wish for racial (white) sameness in the area, thus giving ground to the racial motive behind the single-family zoning. Single standing housing dwellings built in these areas are at the same time more expensive and accessible to a certain percentage of Americans. (investopedia, 2022)
The income and racial segregation that single-family zoning constructs is still very valid today. Movements like the Not In My Backyard (NIMBY) oppose more affordable, multifamily developments that could provide opportunities especially for ethnic minorities in these low dense neighborhoods and change the urban fabric to a more diverse one.
Social activism, as well as the growing need for more affordable housing as an answer to the housing shortage in the US have put single-family zones under discussion - on local and national levels. Already many cities have rezoned single-family into multifamily areas in the past 10 years, such as Minneapolis, Gainesville, and Buckhead, with likely more cities and municipalities to follow. (Bloomberg, 2022)