The Montgomery County Council voted unanimously Tuesday to pass a zoning amendment that would loosen regulations for auxiliary dwelling units, or ADUs, allowing thousands more residents to transform garages, basements or detached structures into separate residences.

The decision comes after months of heated discussion in Maryland’s most populous jurisdiction between officials who see the need to update the county’s zoning ordinances and a vocal group of owners of single-family homes who see the amendment as a furtive attempt at upzoning and a threat to their vision of suburban living.

“Throughout this process, we’ve heard from voices of exclusion,” said County Council member Hans Riemer (D-At Large) to public observers in the council’s hearing room, some of whom wielded homemade protest signs in opposition to the bill. “I want to thank my colleagues for being resolute in the face of that criticism.”

Opposition started when the bill was introduced in January and culminated in a petition submitted to the council last week with more than 1,100 signatures. This group’s members, predominantly owners of ­single-family homes, say ADUs will worsen congestion and school overcrowding and potentially alter the character of their neighborhoods.

In response, officials and planning experts say that ADUs can help accommodate family members looking to stay closer to each other or new residents seeking affordable housing.


Gail Weiss (right), a lifelong Bethesda resident, waving to passing drivers outside the Montgomery County Council building during a protest against a zoning amendment July 9. (Rebecca Tan/The Washington Post)

“I was just so disappointed that no one voted against it despite the vocal opposition,” said Carol Placek, one of about a dozen residents who turned up to protest the bill at the council’s headquarters in Rockville.

Trina Leonard, 68, agreed, adding that she thinks the zoning change “represents a departure from Montgomery’s historical planning.”

For Riemer and other advocates, this was something to celebrate.

“We are a community that historically has been shaped by single-family zoning, and in the early days, that was substantially to keep out communities of color,” the council member said in an interview. “We’ve changed.”

While the vote brings a temporary close to the testy discussions around this specific zoning amendment, residents on opposing sides of the issue remain divided.

Eric Saul, an architect from Takoma Park, said he knows of at least six residents in the Silver Spring area who are planning to build ADUs once this amendment goes into effect Dec. 31. Leonard, on the other hand, said her homeowners association in the Windermere neighborhood of North Bethesda, which she helps oversee as vice president, has its own set of rules around ADUs and does not plan to change them to allow more.

With the vote, Montgomery joins Arlington, the District and other jurisdictions across the country turning to ADUs as part of a broader effort to achieve what experts call “gentle density” — a strategy to accommodate burgeoning populations without causing dramatic disruption to existing neighborhoods.