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ACCESSORY DWELLINGS

Understanding Affordable Housing

Affordable Housing Investment Fund

Market Rate Affordable Housing

ACCESSORY DWELLINGS

Accessory dwellings are additional, often small, housing units located within or adjacent to single-family homes. They are frequently known by more descriptive names such as basement apartments, granny flats, backyard cottages, in-law suites, and carriage houses. A property owner with an accessory dwelling can live in either the main dwelling or the accessory dwelling while renting out the other unit.

Accessory dwellings are one way of adding to the supply of housing in single-family neighborhoods without altering the character of the area.

Because of their size and characteristics, these units are often rented at rates that can be affordable to low- or moderate-income individuals. They are also often one of the only options for smaller rental apartments in some areas of a community, providing a valuable housing option for those who need it.

Accessory dwellings can also help elderly homeowners age in place. Caregivers or family members can occupy either the accessory unit or the main home. For homeowners who choose to rent the accessory dwelling, this can provide a valuable supplemental source of income.

Timeline: Accessory Dwellings in Arlington

July 2008 Arlington begins allowing accessory dwellings that are no more than 750 square feet within a single-family home (example: basement or attic apartment).

November 2017 Regulations are updated to allow conversions of existing detached buildings into accessory dwellings (example: converted detached garage).

May 2019 Arlington allows construction of new detached accessory dwellings.

Arlington County adopted an ordinance in 2008 that allowed accessory dwellings generally no greater than 750 square feet within a single-family home. Detached accessory dwellings – such as backyard cottages or detached carriage houses – were not allowed in Arlington. In December 2017, the County Board approved updates to the ordinance that streamlined the rules and allows conversion of existing detached accessory buildings (such as garages) to be converted to accessory dwellings. In May 2019, the County Board approved allowing new construction of detached accessory dwellings. See the resources below for additional details on all these updates.

Learn More: Accessory Dwellings in Arlington

Arlington’s accessory dwelling permit process is managed by the zoning office of the Department of Community Planning, Housing, and Development. Follow the links below to learn more.