FAQs: Accessory Dwelling Regulations Update

On Nov. 27, 2017, the Arlington County Board adopted an ordinance updating the accessory dwelling regulations in the Zoning Ordinance; which governs second dwellings with a kitchen, bathroom, and a separate entrance on existing single family lots. Visit the Building Arlington website to apply for an Accessory Dwelling (AD) Permit.

Arlington County is updating its accessory dwelling regulations, which governs second dwellings with a kitchen, bathroom, and a separate entrance on existing single family lots. A citizen-led Working Group is working with staff on draft recommendations on improving the ordinance, which went into effect in 2009. Learn more about the update.


What is an accessory dwelling?

An accessory dwelling (AD) is a second dwelling with kitchen, bathroom, and separate entrance on a single family lot. In Arlington, ADs are only permitted inside single-family detached houses, e.g. in a basement, on the second floor, or in an addition to the home. More information on regulation provisions.

What are the benefits of an accessory dwellings?

Accessory dwelling units provide supplementary housing that can be integrated into existing single-family neighborhoods to provide a typically lower-priced housing alternative. AD units can help promote the supply of rental housing for older adults and persons with disabilities. Homeowners can also build AD units to receive additional income and/or to allow them to remain in a home otherwise too big to fit their needs.

Why is this issue coming up again?

Several issues have been identified that limit usage. Since 2009, when the regulations became effective, only 20 accessory dwelling units have been approved. Adjustments to the existing accessory dwelling unit regulations was one of the County Board directives to undertake in order to advance the goals of the Affordable Housing Master Plan. Accessory dwellings was identified as an existing tool in the Plan to help meet the stated goal of having an adequate supply of housing to meet community needs as well as provide support so that older adults can age in place. The Plan recommended review of the regulations to encourage greater use.

Who is reviewing the ordinance?

A Working Group has been set up to assist staff in determining what changes need to be made to the accessory dwelling regulations in order to encourage greater usage while preserving Arlington’s single-family neighborhoods. The Working Group is made up of members of the Housing Commission, two members from the Commission on Aging, a member from the Civic Federation and a member from the Alliance for Housing Solutions.

What is the schedule?

The Working Group and staff are meeting to come up with draft recommendations between now and the end of April. These recommendations will be shared with the community and comments will be received via a survey (more information coming soon) and a community meeting on May 13. Based on public comment, the recommendations will be revised and then sent to the Board for a request to advertise changes to the accessory dwelling ordinance in October with final Board consideration in November.

Anticipated Commissions and County Board Schedule

  • Zoning Committee (ZOCO) (September 12)
  • Neighborhood Conservation Advisory Commission (September 14)
  • Housing Commission (October 12)
  • Commission on Aging (October 16)
  • Disability Advisory Commission (October 17)
  • County Board Request to Advertise (October 21)
  • Planning Commission final consideration (November 6)
  • Housing Commission (November 9)
  • County Board action (November 18) 

How can I get involved and where can I get more information on this process?

For more information or to add your name to an email list serve for upcoming events, email Joel Franklin.