Rick and Pavy Bacon are converting the detached garage behind their Silver Spring home into a secondary dwelling where Pavy’s parents will live. Photo by Michael Ventura

The detached four-car garage wasn’t what attracted Rick and Pavy Bacon to the Silver Spring home they purchased 10 years ago. In fact, they didn’t even own a car at the time. “We had a scooter,” Pavy says. What sold them was the charming bungalow style architecture of the home, a neighborhood that was near public transportation and not far from the District, and good schools for the children they hoped to have.

Over the years, the Bacons always thought the garage would be more useful if they converted it into an apartment rather than using it as a storage shed. So they were thrilled when the Montgomery County Council unanimously approved a zoning amendment in 2019 to ease restrictions on accessory dwelling units (ADUs).

Last summer, the Bacons got a permit to convert the detached garage on their quarter-acre lot. They hired Eric Saul of Saul Architects in Takoma Park to design an in-law apartment for Pavy’s parents, who live in Wheaton after relocating from Singapore to help with the couple’s two young children and be a part of their daily lives. “I think it’s the perfect solution for aging in place,” says Pavy, who is looking forward to having her parents living just across the backyard, where her kids can visit anytime, once the construction is finished this summer. “It’s a mutually beneficial relationship, and it also makes good financial sense for all of us,” she says.

Secondary dwellings—whether they’re called a granny flat, an in-law suite, or a guest cottage—on the same parcel as a single-family home are nothing new. Montgomery County has long allowed licensed rental units (living quarters with a bathroom, full kitchen and a separate entrance) inside of homes; most are basement apartments. Detached living quarters, however, were only permitted on residential lots larger than 1 acre.

The zoning ordinance changes, which went into effect on Dec. 31, 2019, removed several of the old constraints, including limits on the number of ADUs allowed per neighborhood, and streamlined the permitting process. One of the major shifts was eliminating the 1-acre rule. Officials hope this change will translate into more lifestyle flexibility and rental income potential for local homeowners who live on smaller suburban lots and want a secondary dwelling on their property. Saul advocated for passage of the amendment. “I supported the changes because the market, and my client base, needed it,” he says. “They were missing out on economic opportunities because of all of the restrictions.”

Chris and Lisa Puchalla wanted their guest cottage in Chevy Chase, D.C., to look as if it had always been there. It was designed to mimic the charming style of the century-old main house, with wood clapboard siding, a slate roof and copper gutters and downspouts. Photo by Helen Norman

Zoning guidelines regarding lot coverage, square footage, height, setbacks, parking, and stormwater management continue to apply. The size of a detached ADU must be the least of: 50% of the footprint of the principal dwelling, 10% of the lot area, or 1,200 square feet of gross floor area, according to Ehsan Motazedi, deputy director at the Montgomery County Department of Permitting Services.


The revisions are part of a larger effort to address a significant housing need in the county. Studies show continuing population growth, with a projected increase of more than 60,000 new households by 2040. Officials think that reducing restrictions on single-family home zoning will allow for a wider variety of housing types for singles, young adults, older people or anyone who needs a smaller, more affordable place. “We need options for the ‘missing middle,’ and ADUs are just a part of the formula for solving the bigger housing issue,” says William Kirwan, a principal at Muse Architects in Bethesda and a former chair of the Montgomery County Historic Preservation Commission.

The concept is gaining in popularity nationally, but few people appear to know that it’s allowed here. In 2020, the county granted only six permits for detached ADUs, according to the Department of Permitting Services. The Bacons’ project was one of them. “The new rules went into effect just a couple of months before the pandemic, so I think that 2021 will be busier,” Saul says.

The recent buzz about so-called “tiny houses,” which are typically less than 600 square feet in size, the need for more space for extended family, and the potential for extra income are expected to pique local homeowners’ interest in building an ADU. According to real estate agent Lisa Stransky of Washington Fine Properties in Potomac, many homebuyers would like a property with an ADU, but such units are uncommon in the suburban Washington, D.C., market. “If a property is lucky enough to have one, I do think it adds financial value,” she says. Marc Fleisher, executive vice president of The Fleisher Group at Compass in Chevy Chase, also thinks that ADUs can be an asset. “It is not easy to find detached structures to establish as additional full-time living space,” he says. “I think it will certainly be a plus for some homeowners.”

Durable materials and furnishings—soapstone countertops, black leather chairs, performance fabrics on the sofa and headboard, outdoor resin wicker counter stools, a dark patterned rug—stand up to high traffic. Photo by Helen Norman

Local builders, including FineCraft Contractors Inc. in Gaithersburg and Bethesda-based Case Architects & Remodelers, are already building detached ADUs in the District and Arlington, Virginia, jurisdictions that were ahead of Montgomery County in amending their zoning laws. John Audet, director of project development at Case, is currently building a 400-square-foot home behind a house in Northeast Washington, where the family’s grandmother is expected to live. “It’s a great way to give people options now and down the road,” he says. “I hope these types of spaces become more a part of people’s thinking.”

FineCraft Business Manager Niko Papaheraklis has been fielding inquiries from Montgomery County residents about building ADUs, and the firm is preparing to begin some projects. “The pandemic has gotten people thinking about staying in their homes and making better use of the spaces,” he says. His company is in talks with an architecture firm to develop a series of predesigned and pre-engineered plans to simplify the process.

The price tag for building a freestanding dwelling likely will deter some curious homeowners. The cost can range from $200,000 to $400,000, depending on the size and complexity. Building a foundation and running utilities—electricity, water and sewer—to another structure can be expensive. “It’s much more cost effective to build an apartment inside a house, where you already have access to those things,” Kirwan says.


While Montgomery County adds more ADUs to its inventory, here are two examples of small structures in Upper Northwest D.C.

The interiors of the Puchallas’ ADU are low maintenance and neutral, with a backdrop of Benjamin Moore Simply White paint to keep the spaces feeling light and bright. A chic black, white and gray color palette creates timeless appeal for renters. Photo by Helen Norman

The flexibility of a backyard dwelling is what motivated Lisa and Chris Puchalla to build a small house on the site of a former single-car garage adjacent to their 1907 colonial in Chevy Chase, D.C. After living in their home for almost 20 years and raising three children there, they started considering new ways of using the leafy, 7,000-square-foot property.

“We were toying with the idea of redoing the old garage as my office,” says Lisa, an interior designer who owns LilyMae Design. But as they explored their options, they realized that erecting a secondary unit on the site represented income potential. “We got more and more excited about building a little house, and the idea of renting it out,” she says.


The couple enlisted Chris’ brother, contractor Dominic Puchalla of Fairchild Construction in Northwest Washington, to build it, and Neal Thomson of Thomson & Cooke Architects, also in Northwest, to create a design that mirrored the style of the main house, with gray lap siding and a mansard roof with slate shingles. “We wanted a miniversion of the main house, and for it to look like it had always been there,” Lisa says. When the plans were finalized and approved, the Puchallas shared them with their neighbors, who luckily were all on board. “They were all so nice, and they could see that we were going to build something super cute,” Lisa says.

The two-level unit is 600 square feet above ground, with a kitchen, living room, bedroom, bathroom, and laundry area, and 350 square feet below grade. The cost of construction was about $300,000. “We were losing our garage storage, so Dominic dug out a basement with an 8-foot ceiling that’s accessible from an exterior staircase entrance,” Lisa says. The family uses the space to store yard tools, suitcases and Christmas decorations, and Lisa has put up racks to hold styling items for her business.

Architect Kate Donahue used black window frames and a mix of horizontal and vertical siding on the exterior of Mark and Jill Stacey’s 465-square-foot modern style ADU in Friendship Heights. “It breaks up the monotony,” Donahue says. Photo by Morgan Howarth

The “baby house,” as they call it, has been inhabited often in the last three years. When the couple remodeled the main house, they moved into the smaller home for 10 months. “I actually loved every minute,” Lisa says. “It has everything we needed, just on a small scale, and it’s very convenient.”


The Puchallas used the space to house visiting family and friends before deciding to advertise it for rent. Lisa admits she was somewhat uncertain about renting at first, but has had good luck with tenants. “We are very careful and always do background checks,” she says. She’s hosted a diverse group, including a neighbor’s son and daughter-in-law, who wanted to be nearby during the pandemic; a newly separated dad; and a couple who wanted to try living in Chevy Chase before committing to a move there. “We’ve loved our clients,” Lisa says. “We’ve met some really great people.”

The Puchallas are already dreaming about how the little house will factor into their next phase of life. “We would even consider retiring there,” Lisa says. “We love to travel, so we could keep it as a home base and rent out the main house.”

The bedroom is upstairs, along with a full bathroom and a washer and dryer. Hardwood floors add warmth, and the windows flood the space with natural light from every direction. Photo by Morgan Howarth

Investment opportunities are just one of the reasons homeowners are building ADUs. As perspectives on multigenerational living change, in part because of the pandemic, people like the Bacons are recognizing the benefits of having grandparents nearby and providing independent living spaces for them.


Keeping family close by was the impetus for the accessory unit that Jill and Mark Stacey built in 2019 behind their Friendship Heights home in Northwest D.C. Mark grew up in the neighborhood, and his mom still lives there. The couple wanted to build a small house for her so she wouldn’t have to move away when she’s ready to downsize.

“I’d seen the small accessory houses they were building in cities like Portland, Oregon, and was inspired by the contemporary designs in magazines like Dwell,” Jill says. “The zoning laws had changed recently, and this became something we could do.” The couple decided to explore the idea, and consulted with Four

A simple black and white color combination is jazzed up with a mix of hexagonal and subway tiles. Photo by Morgan Howarth

Brothers Design + Build, a D.C.-based firm that was building an addition for them at the time. The firm had just completed its first ADU project in Northwest D.C. and gave the couple a tour of the two-story home.


The Staceys liked what they saw. Their spacious backyard provided plenty of room for a sizable two-story structure, while adhering to the city’s 20-foot height restrictions. Architect and project manager Kate Donahue planned around several existing trees and tucked the building into a shady rear corner, so there is still plenty of yard space.

To maximize the footprint, Donahue designed a practical, boxy house. “The two squares allowed us to create a space for a stairwell with storage underneath,” she says. The family’s main residence is a traditional brick colonial with a slate roof, but the rear addition is more modern, so Donahue played off that design for the little house.

Although building codes require only one door, the house has two entrances. A single door leads to a parking pad on the alley, and double doors open to a patio and the backyard, with views to the deck of the main house. When the weather is nice, Mark’s mom will be able to sit on the patio and watch the kids play in the yard.


Inside is an open, airy and multifunctional space with a second-floor bedroom, bathroom and laundry area. There is also a bathroom on the first floor, and extra space for a bed if climbing stairs becomes an issue for Mark’s mother. “We were designing for the present, but planning for the future,” Donahue says, “which is always a good idea.”

Carolyn Weber lives in Silver Spring and frequently writes about architecture and home design.