County Board Paves Way for More Accessory Dwellings Units

Many Arlington homeowners can now build backyard cottages, thanks to a vote from the County Board.

Board members unanimously voted to loosen zoning regulations on so-called detached “accessory dwelling units” (ADUs) during their Saturday meeting. The vote came after a contentious discussion with residents who said they feared the impacts of greater density and fewer trees in their neighborhoods.

“I am very pleased to support this motion for the benefits I think we’re going to see,” Board member Erik Gutshall said. “In my view the benefits far outweigh the potential impacts. To me it’s about housing. Period.”

Board members have long eyed small backyard homes as a way to help increase the county’s available affordable housing stock.

The newly amended zoning rules allow Arlington homeowners to build detached ADUs on their property without first seeking county permission to do so — as long as it’s a one-family property. Previously, homeowners could only build an ADU inside their house (such as an English basement) or convert an existing outside structure into one.

Now, homeowners can build an ADU on an interior lot as long as the structure is at least 5 feet away from the property lines. ADUs built on corner lots must sit 5 feet from the side yard line and 10 feet from the rear yard line.

Previously, the County Board debated whether to allow 1-foot setback distances, but members ultimately nixed the idea, citing privacy concerns between neighbors and the fact it would only increase the number of ADU-eligible properties by 2 percent.

The exact distance didn’t matter to Urban Forestry Commission member Phil Klingelhofer, who said Saturday he had “serious concerns” about allowing any detached ADUs because laying sewer lines and footings anywhere could hurt the county’s tree canopy coverage.

“I want to make sure that we’re not… losing the forest for the trees,” Board member Katie Cristol replied. “Nationally, the biggest driver of emission and therefore climate change is sprawl development.”

Previously, several members of the activist Arlington Tree Action Group cited concerns about ADU construction killing trees and adding impervious surfaces to the county, which is already at a higher risk of floods.

Among the opponents was former County Board member John Vihstadt, who said the measure was part of a bigger mismanagement of density and natural resources.

“We must do better with managing our growth,” he said.

County Housing Planner Joel Franklin said since Jan 1, 2018, the county has approved 10 requests to build ADUs, three of which were converting existing structures into detached backyard cottage-style units.

A March draft of the policy estimated that 44 percent of Arlington’s one-family residential lots would be eligible to build ADUs under these rules, but Board members said Saturday they believed homeowners would build ADUs slowly.

However, Board members appeared to be confused about the rules regarding using ADUs as Airbnb rentals — along with tree removal and neighborhood notice of ADU construction — and had to frequently ask staff for regulatory clarifications.

“I’m hoping that as we move forward, maybe in a year… I would like to have a report back to us and the community about how this is working out,” said Board Member Libby Garvey, at the end of the discussion. “What’s happening to the trees? What’s happening to the uses? Just what’s really going on?”

Another point of the contention on Saturday was the Housing Commission’s recommendation that the county establish a zoning appeals process for homeowners to ask for regulatory exceptions to the new ADU zoning rules.

“We know that lots in Arlington are so irregular that situations can arise where something may not fit in something that’s been designed at this point,” said Arlington Housing Commission member Alice Hogan. She added that homeowners and zoning staff could work together on those special appeal cases.

“Staff currently does not recommend establishing a way to seek modifications to, or potentially relief from, the use standards of accessory dwelling units at this time,” said Associate Planner Timothy Murphy, citing concerns that homeowners may try to make buildings that rival the size of their main house.

Saturday’s rule change did not alter the county’s other requirements that an ADU must:

  • Have a separate entrance
  • Have its own kitchen and bathroom
  • House no more than three people
  • Be no bigger than 750 square-feet
  • Pass a fire-safety regulation inspection

“We have dealt with this 12 years ago, two years ago, one year ago, and today,” Hogan said of the county’s many revisions to ADU zoning regulations. “So it’s definitely an iterative process.”

“Even though I think we’re going to take some action today that will move us further, I don’t think it will be the last one,” said Board Chair Christian Dorsey.

Images via Arlington County