Arlington County, a close-in suburb of Washington, D.C., has approved a wide-ranging housing reform bill that makes it one of the first jurisdictions on the East Coast to eliminate single-family-only zoning.

The policy, approved unanimously by the five county board members Wednesday evening, aims to increase housing supply in the 26-square-mile county by allowing lots that could previously only have one home to accommodate two to six units.

The vote culminated a contentious, more than three-year process in which Arlington conducted a Missing Middle Housing Study to analyze the need for allowing multi-unit properties.

More than 200 residents spoke at two days of animated hearings, with some voicing a need to allow more affordable housing options to increase the county's diversity, and others expressing concerns that the added units would overwhelm county infrastructure, The Washington Post reported.

The policy will begin to take effect July 1 but will be phased in over five years. Only 58 permits will be allowed each year for these multi-unit properties until 2028, when the cap would be lifted.

The number of units allowed on a property would depend on its size, with only lots over 6K SF being able to accommodate five or six units. The buildings still must adhere to the same rules around height, lot coverage and setbacks that applied to single-family homes.

Arlington, with a population of around 233,000, has long allowed high-density development around its Metro stations with a drop off to single-family homes in the surrounding neighborhoods. The county across the Potomac River from the nation's capital has faced increasing pressure on its housing market in recent years, especially since Amazon selected Arlington for its second headquarters in November 2018.

Arlington County Board Chair Christian Dorsey at Wednesday's meeting called the county's single-family-only zoning a "vestige of old times," ARLnow reported.

“By allowing natural increases in the housing supply, we will lower the barriers of entry into all neighborhoods and, in doing so, address the housing crisis and our history of exclusionary zoning head-on," Dorsey said in a statement.

The movement to eliminate single-family-only zoning has begun to gain momentum in recent years as the nation faces a serious housing shortage.

Minneapolis made national headlines when it eliminated single-family zoning in December 2018. In 2019, Oregon became the first state to end single-family zoning. In September 2021, California passed a law to effectively abolish single-family zoning across the state, and Maine became the third state to pass such a policy in April 2022.

At least eight municipalities have now passed single-family zoning bans in addition to the three states, but Arlington is one of the only jurisdictions to allow six units on some formerly one-unit lots, The Washington Post reported.

“It’s an amazing step forward,” Bryan Coleman, a vice president of the NAACP’s Arlington chapter, told the Post.