November Hearings Set on Proposed Accessory Dwelling Regulation Chang

Published on October 21, 2017

  • Working to increase accessory dwelling opportunities, maintain residential neighborhood character

  • Only 20 accessory dwellings approved since 2009

  • Hearings set before Planning Commission, County Board

The Arlington County Board in November will consider proposed changes to its accessory dwelling regulations that are meant to increase opportunities for residents to add accessory dwellings, while maintaining the character of residential neighborhoods.

Since the County's first regulations of accessory dwelling units took effect on January 1, 2009, only 20 such units have been approved. The units are defined as second dwellings with a kitchen, bathroom and separate entrance on a single-family lot. They must be attached to single-family detached houses (such as basements, on the second floor, or in an addition).

"We are revisiting these regulations because they have not met the goals the Board sought when we first voted to allow accessory dwelling units," County Board Chair Jay Fisette said. "Our goal has always been to create another form of low-to-moderate income housing, and to help Arlingtonians age in place by allowing them, in carefully controlled circumstances, to have the option of creating an accessory unit that would provide another stream of income. We have also been clear that we will maintain the character of our residential neighborhoods. I think the extensive community process and our experience since first enacting regulations has helped us craft a better, more realistic approach."

The Board voted unanimously  to set a public hearing before the Planning Commission November 6 and before the Board at its November 18 meeting on the proposed changes to the accessory dwelling regulations. To read the staff report, visit the County website. Scroll down to Item No. 44 on the agenda for the Oct. 21, 2017 Regular County Board Meeting.

Key proposed revisions include:

  • Allow for accessory dwellings in detached accessory buildings

  • Increase the maximum occupancy from two to three

  • Increase the maximum square footage for an accessory dwelling wholly within a basement

  • Remove the minimum lot width and area restrictions on creating Ads on nonconforming lots

  • Remove the requirement that a resident must live in the dwelling for one-year prior to applying for an accessory dwelling

  • Some revisions to design requirements to allow for more flexibility


The County's initial regulation of accessory dwellings was restrictive, in response to community concerns about the then-unknown impacts of the new accessory use, including overcrowding, parking and traffic. The 20 approved units located throughout the County since 2008 have generated no complaints. The proposed changes are meant to add more flexibility to the regulations.

Public engagement

Staff developed the recommendations with a Working Group. Staff held a community meeting to gather feedback on the proposed regulations on May 13, and opened an online survey over the summer. Various advisory groups and commissions — including the Planning Commission, Housing Commission and Commission on Aging — will be weighing in on the recommendations before the November Board meeting. Learn more about the update process on the County website. The public is invited to comment on the proposed regulations at the Nov. 18 County Board Meeting. Visit the County website for information on speaking at a Board Meeting.