Worried about ADUs in Falls Church? Studies Reveal Community Benefits, If Involved

Have doubts about ADUs (Accessory Dwelling Units) coming to your neighborhood?

Not to worry. 

Numerous studies around the country, and in the Commonwealth of Virginia, reveal that with ample community input and sensible regulatory parameters, the municipal allowance of ADUs – also known as “granny flats,” “secondary suites,” or “backyard cottages” – offers substantial benefits both to local communities and homeowners. 

City of Falls Church Mayor Letty Hardi has actively promoted the City’s adoption of zoning codes and regulatory allowances for homeowners to build ADUs on their properties. 

And, with the support of several pro-housing City Council members, and the City’s Planning Department, she’s moving to ensure city planners hear from local community members about ADU concerns, while the regulatory parameters on the building and maintenance of ADUs comport with Virginia’s statewide housing standards, per Virginia’s Comprehensive Plan and the state's Department of Housing and Community Development's (DHCD) Consolidated Plan.  

So, What Exactly is an ADU? 

Per the DHCD, it’s “an accessory to a single-family primary dwelling unit on the same property” that “can be attached, internal or detached to the primary dwelling unit and [is] most often considered a separate living space.” As a “dwelling unit,” an ADU must be on a “residential lot with its own living, bathroom, and kitchen space.” And there’s no legal requirement that it serve as “affordable housing,” i.e., purchasable by households below the area median income (AMI).

Mayor Hardi Promotes ADUs

Mayor Hardi reassured constituents in her weekly newsletter Nov. 8 that the Accessory Dwellings (AD) policies she supports are “based on national best practices, input from 9 public meetings and City boards and commissions, input from 4 open house meetings, and analysis of proposed state code legislation.” 

And she's looking forward to hearing more from the community and major stakeholders.

“As a refresher, here are the benefits and considerations when considering ADs – which will be familiar slides if you attended the open houses,” Hardi wrote. “Detached ADs offer a choice in how someone can use their property to meet their specific needs – vs right now, the only option for 70 percent of the city’s land is a single family home. An important note: ADs are not an affordable housing strategy by the strict definition, but they are less expensive forms of housing especially relative to current options in neighborhoods. And they offer supplemental income if rented out, which can help offset living expenses for the owner.

In the slides, Hardi outlines both the “benefits” and “considerations” of ADUs. 

On the positive side, they can help families “age in place,” by providing “housing options for dependent or multigenerational family members that may need or want to live nearby.” They can help homeowners supplement their incomes by “renting their ADs.” And, they can increase “housing diversity and inclusivity” by providing “smaller, less expensive housing options than typical detached single-family homes.” 

Some “considerations,” however, include possible “environmental impacts,” such as increasing “impervious surface and building coverage,” “stormwater” runoff, and possibly reducing “tree canopy.” Neighborhood impacts on “equity” and “privacy” must be taken into account. And, “facilities impacts,” such as for “storm and sanitary sewers” and for schools must also be factored in.

Hardi continued: “The staff report has a lot more detail, but here’s a summary of the current staff recommendations. An overarching principle is to lower the cost and barriers to building an accessory dwelling so that it can be a more realistic choice, while balancing the considerations above.”

• Gross floor area (aka size of the AD) – lesser of 1K square feet or 50 percent of the primary dwelling.
• Lot coverage – same as current rules (25 percent building coverage, 35 percent impervious coverage) to preserve open space and mitigate stormwater runoff.
• Height and setbacks – sliding scale option 20′ tall if 5′ setback (1.5 stories), 25′ tall if 10′ setback (2 stories). For reference, single family homes are allowed to be 35′ with a 10′ side setback and sheds/garages/accessory structures are allowed to be 12′ tall with a 3′ setback.
• Parking – no off-street parking requirements, as it increases impervious surface area and cost of construction.
• No owner occupancy requirement, which presumes a negative association with renters that is not born out in the data. Owner occupancy requirements would introduce complications should owners need to move for job reasons or others.
• Short term rentals – currently we do not have rules regulating short term rentals because we haven’t been a market for short term rentals. We have “nuisance” ordinances that regulate issues such as trash, upkeep, noise, etc., that can be applied to all properties.
• Conversion of existing structures (for example, garages) into ADs would be allowed via a special use permit process that would go to the Board of Zoning Appeals.

But, the City of Falls Church will not be alone in allowing ADUs. Several surrounding areas have done so as well,” Hardi said.

“Nearby jurisdictions have legalized similar rules for accessory dwellings,” she wrote. “To date, Alexandria has 63 accessory dwellings (internal and detached) since 2021, and Arlington has 78 since 2014… And these areas are over six-to-10 times “our size in geography and population." 

With data showing that “ADs represent less than 10 percent of all single family homes built,” Hardi wrote, “qualifying parcels in Falls Church, and cost of construction ($200K+), [planning] staff estimates Falls Church could see 2 accessory dwelling units per year,” as opposed to twenty new Single-Family Homes (SFHs) built per year.

What’s the City Calendar on ADUs?

The City held an “exhaustive discussion at its work session” on Nov. 4, as the City Council “mulled options for revisions in the City’s zoning code to allow for the building” of ADUs, per the Falls Church News-Press. The City Council is also planning a “robust round of hearings before a variety of volunteer boards and commissions” on ADU issues. A “first reading” vote will then be held Nov. 25. And a “final consideration” on the ADU measure(s) are scheduled for March, 2025.

The City Planning Office’s Perspective

In its most recent staff report on the issue of ADUs, the City’s Planning Office, citing national and state-level research, reassured the public that ADUs in the City of Falls Church – if properly regulated and considerate of local historical norms – can prove beneficial to the community. 

“Regulations on accessory dwellings [ADs] have been adjusted in some localities across the country as a tool for increasing housing availability and reducing housing costs while having limited impacts on community character or sense of place,” Jack Trainor, AICP, Senior Planner in the City Planning Office, wrote for the staff. “Common uses for accessory dwellings include housing for extended family members or family members that need to live nearby, and providing a source of supplemental income for homeowners. Regulations for accessory dwellings in communities across the country and locally within the region address numerous dimensional and programmatic standards. This is a common practice in zoning ordinances, and decisions can be complicated because accessory dwellings often involve development within existing neighborhoods.” 

Despite such “complications,” however, local residents can provide city planners with sufficient feedback about how ADUs might impact their neighborhoods, and the City Council can make necessary modifications.

By Falls Church City Code, ADUs in The Little City must also meet the City’s elevated standards, as they are required to provide “permanent provisions for living, sleeping, eating, cooking and sanitation for use by one family within the limits set forth in this Code pertaining to health, building, or other relevant provisions of the law.” 

Currently, there are no permitted ADUs in the City. With approval, however, that could begin to gradually change.

National and State-Level Study Findings in Support of ADUs

Harvard University 

Harvard University’s Graduate School of Design researcher Ellie Sheild highlights significant community benefits from ADUs in her 2023 study Learning from State Efforts to Encourage Accessory Dwelling Units. According to Sheild, ADUs have the “potential to address such housing-related challenges as affordability, equity, and sustainability.”

Sheild describes how “over the last two decades, many cities and towns have changed their zoning to allow by-right approval of ADUs that meet clear standards for their size and use.” She explores how effective policymakers and politicians – sensitive to the needs of their communities – eventually defeated the “self-reinforcing negative cycle” of powerful and outspoken “homeowners oppos[ing] efforts to allow ADUs, usually because of concerns about traffic, neighborhood character, and property values.” 

In many cases, “onerous restrictions” such as “limiting occupancy of the ADU to family members, requiring that the ADU’s owners live in the primary residence or the ADU, and/or mandating that the ADU have one or more on-site parking spaces,” had to be enacted.  

Surveying study findings from California, Oregon, Hawaii, Washington, Oregon, Utah, Montana, and the New England States (Vermont, New Hampshire, Connecticut, Maine, Massachusetts, and Rhode Island), Sheild concluded that “ADUs alone cannot fully address a host of housing-related challenges. However, they can be an important part of meaningful comprehensive efforts to address them.” 

The key for policymakers, Sheild concluded, is to understand that “significantly increasing the production of ADUs requires the passage of statewide legislation mandating by-right, local approval of ADUs that meet meaningful state standards related to their size and design.” 

Fortunately, Virginia seems to be moving in that direction.

Virginia’s Department of Housing and Community Development (DHCD) 

Mayor Hardi’s assertion that ADUs don’t serve as an “affordable” housing” panacea for low-income households is confirmed by a report in 2021 from Virginia’s DHCD. But that same report provides ample study evidence evidence to suggest that allowing ADUs to be built can bring significant benefits to a community.

Though DHCD generally advocates for low-income and “affordable housing” measures, the agency’s report Accessory Dwelling Units (ADUs): Presentation of Policy Brief, Literature Review, and Exploration of Regulations in State Laws Concerning ADUs does cite a host of positive benefits from ADUs.

“Many believe increasing [housing] stock may eventually lead to more affordable homes as higher inventory decreases market competition,” the report said. “While constructing an ADU might be out of reach for households not in a high-income bracket,” the report says, “research supports the conclusion that ADUs are increasing housing stock in neighborhoods zoned exclusively for single-family homes.”

For homeowners, an investment in an ADU can increase their property values substantially. “According to the National Association of Realtors,” the report said, “properties in the largest metros with ADUs are priced an average of 35 percent higher than homes without one. This demonstrates an ADU's ability to generate wealth for participating households and promotes ADUs as a potential investment choice.”

ADUs also have significant environmental benefits. According to the report, they have “less of a negative environmental impact compared to standard single-family homes.” Since most ADUs range from between 600 to 1,200 sq.-feet, “they are less likely to have large environmental footprints,” the report said. With their smaller resource usage, ADUs can also help compensate for the fact that “only 3 percent of new single family homes have been under 1,000 sq.-ft. since 1956, making smaller homes, which have less of an environmental impact, scarce,” the report said, citing Sightline research.

Now, as more homeowners are looking to downsize and more home buyers and renters with smaller families are looking for smaller spaces, there’s growing demand for small units like ADUs. The report sites a 2019 National Association of Builders’ study across the U.S. determining that “20 percent of home renovation projects included converting an existing space to an ADU.”

With ample community input, jurisdictions have had success in crafting ADU policies to fit their local needs. 

Due to intense feedback from historical preservationists, environmentalists, residents concerned about crime, noise, or absentee landlords who allow rental properties to decline and thereby lower property values, many examples of regulatory carve-outs were cited in the DHCD report. 

In Maine, “shoreland zoning requirements,” “watershed” and “drinking water” protections were enacted. “California requires newly constructed, non-manufactured, ADUs to provide solar panels, if the unit is a detached ADU.” Vermont “allows municipalities to prevent ADU construction,” if in a flood or erosion area. Washington state protects communities by protecting population density limits, as well as “wetlands, fish and wildlife habitats, flood plains, or geographically hazardous areas.” Oregon, ensures against “wildfire hazards” and mandates that ADUs allow firefighting access.

ADU Laws and Regulations in Virginia

In an article examining “ADU Laws and Regulations in Virginia,” Zoe Harper, marketing specialist at Steadily Insurance, says “ADU laws and regulations in Virginia are becoming a pivotal aspect of urban planning,” and are “revolutionizing the housing landscape.”

Studying the City of Fredericksburg, Virginia, in particular, Harper claims that local officials are “actively amending their Virginia ADU guidelines to foster diverse and affordable housing.”

“By navigating this dynamic frontier, Virginia pioneers a new chapter in residential housing, ensuring adherence to the comprehensive Virginia accessory dwelling units regulations,” Harper writes.

For Harper, ADU codes can be modified to protect architectural history and neighborhood sensibilities, provided “community engagement” is designed into the code-making process.

“In Virginia,” Harper writes, “the conversation surrounding Accessory Dwelling Units (ADUs) has gained considerable momentum as communities look for creative ways to address the need for diverse housing. With Virginia ADU zoning regulations at the forefront, these units have become a vital instrument in urban and suburban development strategies, aiming to enrich neighborhoods with a wider range of living options.”

“Virginia aims not just to increase housing availability but also to provide affordable living solutions tailored to suit an array of inhabitants,” Harper continues. “Whether assisting homeowners with additional income or helping families stay close, ADUs are carving out their place as a versatile and inclusive housing solution within Virginia's growing cities and towns.”

“The quest for affordable housing in cities like Fredericksburg, Virginia, leads to an important conversation" about ADUs — "a potential game-changer in the market,” she continues. “As the city grapples with the multifaceted challenge of housing affordability, the role of ADUs is being closely examined. Not merely additional structures, ADUs embody a shift in housing paradigm, addressing the needs of different community members through a singular initiative.”

“The essence of modern urban development in Virginia hinges on the judicious crafting and implementation of Virginia ADU regulations. With a legislative and regulatory framework that continuously evolves, the state's approach to Accessory Dwelling Units (ADUs) takes shape through meticulous planning and community-oriented strategies,” she writes. “As ADUs emerge as a powerful tool for housing expansion and diversity, understanding the state's direction and specific stipulations within Virginia ADU policies becomes essential for homeowners, builders, and civic planners alike. But the bedrock of these regulations lies in the city's overarching vision for residential growth, encapsulated in the Virginia Comprehensive Plan.”

“A cornerstone of Virginia’s approach to residential planning is the multifaceted Virginia Comprehensive Plan, which actively promotes a mosaic of housing solutions to meet the needs of an ever-changing demographic,” Harper emphasizes. “Advocating for diverse housing types, the plan outlines a mindful integration of Virginia ADUs into communities. It procures the added benefit of accentuating and protecting the chapters of history within the city's districts by prescribing ADUs that align with the existing architectural tapestry.”

Among her key “takeaways:” 

• Virginia is adapting its housing laws to include ADUs, promoting diversity and affordability.
• Fredericksburg stands as a beacon, developing ADU ordinances for future growth.
• ADUs range from basement units to detached structures, expanding housing possibilities.
• Community engagement is crucial in shaping the future of ADU ordinances in Virginia.
• Virginia ADU regulations are designed to honor neighborhood scales and historic aesthetics.
• Compliance with Virginia Uniform Statewide Building Code is mandatory for all ADUs.
• Statewide efforts aim to ensure that ADUs merge seamlessly with existing communities.

“The evolving landscape of housing in Virginia is witnessing a significant shift towards Accessory Dwelling Units (ADUs), propelled by the need to infuse versatility and affordability into local real estate markets,” Harper writes. “As each city strives to calibrate its approach, the complexity of Virginia ADU zoning regulations comes under meticulous examination. These regulations embody the collective goal to harmonize the charm of Virginia’s diverse neighborhoods with the functional essence of modern living.”

“In navigating the intricacies of ADU laws in Virginia, one finds a common thread—each jurisdiction is diligently working towards a customized set of guidelines that consider the distinct character of their environments,” she continues. “This pursuit is far from trivial; it underpins the vision of Virginia to uphold its rich architectural heritage while embracing the oncoming tide of sustainable urban development.”

“Critical to this effort are the Virginia ADU building codes," Harper contends. "They are drafted not only with the objective of safety and durability but also aesthetic consonance with traditional Virginia homesteads. The crafting of these building codes is a balancing act, ensuring that the addition of ADUs to Virginia’s residential tapestry is both seamless and structurally sound.”

For Harper, “the introduction of ADUs across Virginia is more than an architectural feat; it's a catalyst for social and economic vitality, offering an adaptable housing solution to meet the demands of a dynamic populace.”

• Ensuring ADUs are in tune with the architectural ethos of Virginia's neighborhoods.
• Adapting zoning regulations to meet the unique needs of different communities.
• Aligning building codes with modern safety standards without compromising traditional values.
• Advocating for inclusive guidelines that foster diverse housing solutions.

“Community engagement is crucial,” Harper writes. “The process includes public meetings to educate and gather feedback from residents about ADUs. This community input is expected to guide policy recommendations and ultimately influence decisions made by the Planning Commission and City Council."

National Association of Home Builders (NAHB)

In an analysis of ADU ordinances across the United States, the National Association of Home Builders (NAHB) described the municipal consideration of ADUs as a “national trend in the last two decades as people [are] moving back into cities,” creating “more pressure on the demand for housing.”

In a study of ADUs in Portland, the NAHB elaborated on the successful adoption of regulatory parameters that allowed concerned residents to eventually buy into allowing ADUs. Despite some “continued complaints about the proximity of ADUs to property lines, the potential for noise, and concern over short-term rentals,” the report said, “the code construction and communication with the public were vital to the success of ADUs in Portland." 

“With a good code structure and education, people started accepting ADUs,” developer and builder Eli Spevak is quoted saying. “The educational components include regular tours of ADUs done by ADU advocates, a dedicated website on the process, general word of mouth, and seeing neighbors’ homes in progress. All these elements and the recent amendments have really spurred development, such that the number of permit approvals increased to around 500 a year in 2016 and 2017, up from just 80 plus in 2010.”

The AARP

In a recent article entitled  “ADUs are Good for People and Places,” the American Association of Retired Persons (AARP) argues that “communities that understand the benefits of ADUs, allow homeowners to create them.”

A provocative slide opens the piece, asking, “Do we really need more than three times as much living space per person as we did in 1950? Can we afford to buy or rent, heat, cool and care for such large homes?” 

The following bullets from the article help make the case that ADUs improve home affordability in single-family home markets, they can serve effectively in affordable housing and anti-displacement strategies, they help provide homes for people of all ages, and they’re “community compatible.”

• Although market-rate rents for ADUs tend to be slightly more than for similarly sized apartments, they often represent the only affordable rental choices in single-family neighborhoods, which typically contain no studio or one-bedroom housing options at all.
• Some municipalities are boosting ADUs as part of affordable housing and anti-displacement strategies. Santa Cruz, California... is among the cities with programs to help lower-income households build ADUs or reside in them at reliably affordable rents.

ADUs are able to house people of all ages

• An individual’s housing needs change over time, and an ADU’s use can be adapted for different household types, income levels, employment situations and stages of life.
• ADUs offer young people entry-level housing choices.
• ADUs enable families to expand beyond their primary home.
• ADUs provide empty nesters and others with the option of moving into a smaller space while renting out their larger house or letting an adult child and his or her family reside in it.

ADUs are just the right size

• Generally measuring between 600 and 1,000 square feet, ADUs work well for the one and two-bedroom homes needed by today’s smaller, childless households, which now account for nearly two-thirds of all households in the United States.

ADUs are community compatible

• ADUs offer a way to include smaller, relatively affordable homes in established neighborhoods with minimal visual impact and without adding to an area’s sprawl.
• ADUs provide a more dispersed and incremental way of adding homes to a neighborhood than other options, such as multistory apartment buildings. As a result, it’s often easier to get community support for ADUs than for other housing types.

Zillow

According to American tech real-estate marketplace giant, Zillow, ADUs are “having a rock star moment.” 

In an article entitled, “What is an ADU? What to Know Before Building This Popular Living Space on Your Property,” the company asserts that “Scores of cities and counties in at least 35 states and the District of Columbia, and at least nine states, including California, have changed or adopted laws that make it easier and more attractive for homeowners to build ADUs.”

“For many homeowners, ADUs can be a great source of rental income or serve as living quarters for adult children or extended family,” the article says. “They can also be a work-from-home space, or a place to escape to or run a home-based business.”

“Once common prior to World War II, many consider ADUs to be a more affordable source of housing,” the article claims. “This is because you can build them without having to purchase land. Land is usually the biggest component of housing prices, especially in expensive coastal cities.”

“ADUs are still a unique housing type,” the article quotes Kol Peterson, who “teaches and writes a comprehensive blog on the subject. He’s also authored 'Backdoor Revolution: The Definitive Guide to ADU Development,' a book for homeowners considering building one.”

"Legally permitted ADUs tend to add value to a property," Petersen says. "While ADUs don’t promise instant riches, they can be a good way to build wealth. In cities with high housing costs, rental income can pay for the costs of development in a matter of years. Rental income also can provide a homeowner with future options for downsized living without having to move from their home."

"Some localities, such as San Mateo, California, have created ADU calculators to help people determine whether area rents will generate enough to cover monthly expenses," Peterson adds.

Per Zillow, the following benefits are worth noting for ADUs: generating new income; providing “a possible place for relatives to live;” “Flexibility to change with life’s stages without having to uproot;” maximizing one’s investment; and helping to “provide a home to someone else.” 

It’s all about doing what the City of Falls Church is doing – listening to community concerns over ADUs and then crafting policies and codes that ensure reasonable and constructive community housing, building, and safety standards.

By Christopher Jones